Biomedical subjects

A A Wiley

Publications and source records attributed to A A Wiley.

At least 19 recordsLinked to original sources

PubMed2006

Uterine development and endometrial programming.

Structural patterning and functional programming of uterine tissues are mechanistically coupled. These processes ensure anteroposterior differentiation of uterine tissues from adjacent segments of the developing female reproductive tract (FRT) and radial patterning that establishes uterine-specific histoarchitecture and functionality. Uterine organogenesis begins prenatally and is completed postnatally. Genes required for FRT development include Pax2, Lim1 and Emx2, genes in the abdominal-B Hoxa cluster, and members of both Wnt and Hedgehog (Hh) gene families. Disruption of morphoregulatory gene expression patterns can prevent FRT development entirely or compromise uterine organogenesis specifically. Oestrogen receptor-alpha (ER) -dependent events associated with development of the neonatal porcine uterus can be altered by administration of oestrogen (E) or relaxin (RLX). Expression of the RLX receptor is detectable in porcine endometrium at birth, before onset of ER expression and uterine gland genesis. Uterotrophic effects of both E and RLX can be inhibited with the ER antagonist ICl 182,780, indicating that RLX may act via crosstalk with the ER system in neonatal tissues. Exposure of neonatal gilts to E alters temporospatial patterns of Hh, Wnt and Hoxa expression in the uterine wall. Oestrogen given for two weeks from birth produced hypoplastic adult porcine uteri that were less responsive to periattachment conceptus signals as reflected by reduced growth response and luminal fluid protein accumulation, altered endometrial gene expression, and reduced capacity for conceptus support. Data reinforce the concept that factors affecting signalling events in uterine tissues that produce changes in morphoregulatory gene expression patterns during critical organisational periods can alter the developmental trajectory of the uterus with lasting consequences. Thus, uterine tissues can be programmed epigenetically for success or failure during perinatal life.

Animals↗

PubMed2004

Abnormal morphology of the penis in male rats exposed neonatally to diethylstilbestrol is associated with altered profile of estrogen receptor-alpha protein, but not of androgen receptor protein: a developmental and immunocytochemical study.

Objectives of the study were to determine developmental changes in morphology and expression of androgen receptor (AR) and estrogen receptor (ER)alpha in the body of the rat penis exposed neonatally to diethylstilbestrol (DES). Male pups received DES at a dose of 10 microg per rat on alternate days from Postnatal Day 2 to Postnatal Day 12. Controls received olive oil vehicle only. Tissue samples were collected on Days 18 (prepuberty), 41 (puberty), and 120 (adult) of age. DES-induced abnormalities were evident at 18 days of age and included smaller, lighter, and thinner penis, loss of cavernous spaces and associated smooth muscle cells, and increased deposition of fat cells in the corpora cavernosa penis. Fat cells virtually filled the entire area of the corpora cavernosa at puberty and adulthood. Plasma testosterone (T) was reduced to an undetectable level, while LH was unaltered in all treated groups. AR-positive cells were ubiquitous and their profile (incidence and staining intensity) did not differ between control and treated rats of the respective age groups. Conversely, ERalpha-positive cells were limited to the stroma of corpus spongiosus in all age groups of both control and treated rats, but the expression in treated rats at 18 days was up-regulated in stromal cells of corpora cavernosa, coincident with the presence of morphological abnormalities. Hence, this study reports for the first time DES-induced developmental, morphological abnormalities in the body of the penis and suggests that these abnormalities may have resulted from decreased T and/or overexpression of ERalpha.

Aging↗

PubMed2001

Neonatal estradiol exposure alters uterine morphology and endometrial transcriptional activity in prepubertal gilts.

Porcine endometrial development between birth (postnatal day = PND 0) and PND 56 involves differentiation of glandular epithelium (GE) from luminal epithelium (LE) and estrogen receptor-alpha (ER) expression. Juvenile ER architecture evolves after birth, as stroma and nascent GE first express ER. Mature ER architecture is evident after PND 30, when stroma, GE and LE are ER-positive. When administered during discrete periods between PND 0 and 56, effects of estradiol-17beta valerate (EV) on the neonatal porcine uterus relate to endometrial ER architecture. Transient EV exposure from birth reduces embryo survival in pregnant adult gilts. Effects of EV, administered as juvenile endometrial ER architecture develops (P1, PND 0-13), or after mature ER architecture is established (P2, PND 42-55), were evaluated in uteri from gilts treated with corn oil or EV in P1 or P2 and hysterectomized on PND 100 without additional steroids (NSt), on PND 102 after EV on PND100-101 (EV2), or on PND 117 after EV2 followed by progesterone on PND 102-116 (EP). Neonatal EV reduced uterine weight (P < 0.02), size (P < 0.01), luminal protein content (P < 0.07), and percent incorporation of 3H-leucine into nondialyzable endometrial products in vitro (P < 0.01). Group (NSt, EV2, EP) -specific treatment effects detected for endometrial ER, progesterone receptor, uteroferrin, and/or retinol binding protein mRNA levels were frequently related to period (P1,P2). Results support the idea that estrogen-sensitive postnatal organizational events, including those defined, in part, by endometrial ER architecture, are likely components of genetic and epigenetic programs governing uterine morphogenesis and ontogeny of endometrial function in the pig.

Acid Phosphatase↗

PubMed2001

Expression and molecular characterization of estrogen receptor alpha messenger RNA in male reproductive organs of adult goats.

The fact that male estrogen receptor alpha (ERalpha) knockout mice are infertile indicates a role for this receptor in male reproduction. Here, objectives were to evaluate ERalpha expression in male goat reproductive tissues at the transcriptional level using RNase protection assay (RPA) and in situ hybridization (ISH), and to clone a partial cDNA for caprine ERalpha using reverse transcription-polymerase chain reaction (RT-PCR). For RPA and ISH procedures, a radiolabeled antisense cRNA probe, generated in vitro from the ovine oER8 cDNA template, was employed. Evaluations were made on individual samples obtained from adult goats. Labeled cRNA sense probe was used as a negative control in ISH. A 530-base pair amplicon was generated by RT-PCR from efferent ductules (EDs), epididymis (EP), and testis, cloned from the ED and EP, and sequenced. The caprine ERalpha (cERalpha) cDNA displayed 81%-96% sequence identity with that of other species. A signal indicative of ERalpha mRNA was identified by both RT-PCR and RPA in all tissues, but was strongest in the ED. Compared with ED, ERalpha signal was sixfold lower in the EP, and 66-fold lower in the testis. Similarly, strong ERalpha expression was observed in ED epithelium, whereas little or no signal was detected in EP or testis by ISH. Thus, among different segments of the male reproductive tract and testis, the highest level of ERalpha mRNA expression was found in epithelium of the ED.

Animals↗

PubMed2001

Developmental biology of uterine glands.

All mammalian uteri contain endometrial glands that synthesize or transport and secrete substances essential for survival and development of the conceptus (embryo/fetus and associated extraembryonic membranes). In rodents, uterine secretory products of the endometrial glands are unequivocally required for establishment of uterine receptivity and conceptus implantation. Analyses of the ovine uterine gland knockout model support a primary role for endometrial glands and, by default, their secretions in peri-implantation conceptus survival and development. Uterine adenogenesis is the process whereby endometrial glands develop. In humans, this process begins in the fetus, continues postnatally, and is completed during puberty. In contrast, endometrial adenogenesis is primarily a postnatal event in sheep, pigs, and rodents. Typically, endometrial adenogenesis involves differentiation and budding of glandular epithelium from luminal epithelium, followed by invagination and extensive tubular coiling and branching morphogenesis throughout the uterine stroma to the myometrium. This process requires site-specific alterations in cell proliferation and extracellular matrix (ECM) remodeling as well as paracrine cell-cell and cell-ECM interactions that support the actions of specific hormones and growth factors. Studies of uterine development in neonatal ungulates implicate prolactin, estradiol-17 beta, and their receptors in mechanisms regulating endometrial adenogenesis. These same hormones appear to regulate endometrial gland morphogenesis in menstruating primates and humans during reconstruction of the functionalis from the basalis endometrium after menses. In sheep and pigs, extensive endometrial gland hyperplasia and hypertrophy occur during gestation, presumably to provide increasing histotrophic support for conceptus growth and development. In the rabbit, sheep, and pig, a servomechanism is proposed to regulate endometrial gland development and differentiated function during pregnancy that involves sequential actions of ovarian steroid hormones, pregnancy recognition signals, and lactogenic hormones from the pituitary or placenta. That disruption of uterine development during critical organizational periods can alter the functional capacity and embryotrophic potential of the adult uterus reinforces the importance of understanding the developmental biology of uterine glands. Unexplained high rates of peri-implantation embryonic loss in humans and livestock may reflect defects in endometrial gland morphogenesis due to genetic errors, epigenetic influences of endocrine disruptors, and pathological lesions.

Animals↗

PubMed2000

Ovine uterine gland knock-out model: effects of gland ablation on the estrous cycle.

Ovine endometrial gland development is a postnatal event that can be inhibited epigenetically by chronic exposure of ewe lambs to a synthetic progestin from birth to puberty. As adults, these neonatally progestin-treated ewes lack endometrial glands and display a uterine gland knockout (UGKO) phenotype that is useful as a model for study of endometrial function. Here, objectives were to determine: 1) length of progestin exposure necessary from birth to produce the UGKO phenotype in ewes; 2) if UGKO ewes display normal estrous cycles; and 3) if UGKO ewes could establish and/or maintain pregnancy. Ewe lambs (n = 22) received a Norgestomet (Nor) implant at birth and every two weeks thereafter for 8 (Group I), 16 (Group II), or 32 (Groups III and IV) weeks. Control ewe lambs (n = 13) received no Nor treatment (Groups V and VI). Ewes in Groups I, II, III, and VI were hemihysterectomized (Hhx) at 16 weeks of age. After puberty, the remaining uterine horn in Hhx ewes was removed on either Day 9 or 15 of the estrous cycle (Day 0 = estrus). Histological analyses of uteri indicated that progestin exposure for 8, 16, or 32 weeks prevented endometrial adenogenesis and produced the UGKO phenotype in adult ewes. Three endometrial phenotypes were consistently observed in Nor-treated ewes: 1) no glands, 2) slight glandular invaginations into the stroma, and 3) limited numbers of cyst- or gland-like structures in the stroma. Overall patterns of uterine progesterone, estrogen, and oxytocin receptor expression were not different in uteri from adult cyclic control and UGKO ewes. However, receptor expression was variegated in the ruffled luminal epithelium of uteri from UGKO ewes. Intact UGKO ewes displayed altered estrous cycles with interestrous intervals of 17 to 43 days, and they responded to exogenous prostaglandin F(2 approximately ) (PGF) with luteolysis and behavioral estrus. During the estrous cycle, plasma concentrations of progesterone in intact control and UGKO ewes were not different during metestrus and diestrus, but levels did not decline in many UGKO ewes during late diestrus. Peak peripheral plasma concentrations of PGF metabolite, in response to an oxytocin challenge on Day 15, were threefold lower in UGKO compared to control ewes. Intact UGKO ewes bred repeatedly to intact rams did not display evidence of pregnancy based on results of ultrasound. Collectively, results indicate that 1) transient, progestin-induced disruption of ovine uterine development from birth alters both structural and functional integrity of the adult endometrium; 2) normal adult endometrial integrity, including uterine glands, is required to insure a luteolytic pattern of PGF production; and 3) the UGKO phenotype, characterized by the absence of endometrial glands and a compact, disorganized endometrial stroma, limits or inhibits the capacity of uterine tissues to support the establishment and/or maintenance of pregnancy.

Animals↗

PubMed1999

Endometrial development and adenogenesis in the neonatal pig: effects of estradiol valerate and the antiestrogen ICI 182,780.

In the pig, appearance of endometrial glands between birth (postnatal day [PND] 0) and PND 14 involves development of estrogen receptor-alpha-positive (ER+) phenotype by, and increased DNA synthesis in, nascent glandular epithelium (GE). To determine whether ER activation is required for this process, gilts were treated daily with either vehicle, the antiestrogen ICI 182,780 (ICI), estradiol-17beta valerate (EV), or both ICI and EV. Treatments began on PND 0, before onset of adenogenesis, or on PND 7, after onset of gland proliferation. Uteri obtained on PNDs 7 and 14 (study one) or on PND 14 (study two) were weighed; uterine histology was evaluated; DNA synthesis in luminal epithelium and GE was characterized by determining 5-bromo-2'-deoxyuridine (BrdU) labeling index; and patterns of ER mRNA expression were evaluated in situ (study one). Gland genesis was inhibited by ICI, which decreased gland penetration depth by PND 14 in study one, both endometrial thickness and BrdU-labeling index in GE in study two, and increased stromal cell compaction in both studies. Uterotropic effects of EV included increased gland development and epithelial BrdU labeling and decreased stromal compaction. These effects were inhibited by coadministration of ICI. Treatments did not alter ER mRNA expression, which remained limited to stroma and GE. Data indicate that endometrial maturation and adenogenesis in the neonatal pig require expression and activation of a functional ER system.

Aging↗

PubMed1999

Discovery and characterization of endometrial epithelial messenger ribonucleic acids using the ovine uterine gland knockout model.

Prolonged exposure of the developing neonatal ovine uterus to a progestin from birth prevents uterine gland development and creates an adult endometrial phenotype characterized by the absence of glandular epithelium, the uterine gland knockout (UGKO) phenotype. This study used endometrium from normal and UGKO sheep to identify messenger RNAs (mRNAs) expressed differentially in the endometrial epithelium using the molecular techniques of mRNA differential display PCR (DD-PCR) and suppression subtractive complementary DNA (cDNA) hybridization (SSH). Sequence analyses of DD- and SSH-identified and cloned cDNAs indicated similarity of some to known mRNAs, including beta-lactoglobulin, alkaline phosphatase, type B and D endogenous sheep retroviruses, gp330/megalin, matrix Gla protein, and others. Other cDNAs were not similar to any known sequences and are considered novel, although some of these match human expressed sequence tags. In situ hybridization analyses of uteri from cyclic and pregnant ewes indicated that all DD-PCR- and SSH-identified mRNAs were expressed in either the endometrial lumenal and/or glandular epithelium, although some were also expressed in other uterine cell types. Northern and in situ hybridization analyses revealed that patterns of mRNA expression for most clones were affected by the day of the estrous cycle and pregnancy in a manner consistent with regulation by progesterone. Studies demonstrate the utility of the ovine UGKO model as a tool with which to identify known and novel uterine epithelial-specific genes. Cloned cDNAs identified here are expressed sequence tags useful for comparative and physical genetic mapping and may be used to reveal new factors and pathways regulating endometrial function.

Animals↗

PubMed1999

Uterine differentiation as a foundation for subsequent fertility.

Uterine differentiation in cattle and sheep begins prenatally, but is completed postnatally. Mechanisms regulating this process are not well defined. However, studies of urogenital tract development in murine systems, particularly those involving tissue recombination and targeted gene mutation, indicate that the ideal uterine organizational programme evolves epigenetically through dynamic cell-cell and cell-matrix interactions that define the microenvironmental context within which gene expression occurs and may ensure adult tissue stability. In the cow and ewe, transient postnatal exposure of the developing uterus to steroids can produce immutable changes in adult uterine tissues that may alter the embryotrophic potential of the uterine environment. Thus, success of steroid-sensitive postnatal events supporting uterine growth and development can dictate the functional potential of the adult uterus. Studies to determine effects of specific steroidal agents on patterns of uterine development during defined neonatal periods, as well as the functional consequences of targeted neonatal steroid exposure in the adult uterus, should enable identification of critical developmental mechanisms and determinants of uterine integrity and function. Extreme adult uterine phenotypes (lesion models) created in cattle and sheep by strategic postnatal steroid exposure hold promise as powerful tools for the study of factors affecting uterine function and the rapid identification of novel uterine genes.

Animals↗

PubMed1998

Regulation of androgen and estrogen receptors in male excurrent ducts of the goat: an immunohistochemical study.

BACKGROUND: Since androgens and/or estrogens must bind with specific receptors in order to elicit a response at the target organ(s), it is important to understand factors that regulate expression of androgen receptors (AR) and estrogen receptors (ER). Hence, the objective of the study is to determine the relative significance between circulating androgen (CA) and luminal androgen (LA) in maintaining normal expression of AR and ER in male excurrent ducts. METHODS: Mature Nubian goats were subjected for 15 days each to the following treatments: (1) bilateral orchidectomy, (2) bilateral orchidectomy and testosterone treatment, (3) unilateral ligation of the extratesticular rete, and (4) unilateral orchidectomy. Tissues from different segments of the excurrent ducts were fixed in 4% paraformaldehyde and embedded in Paraplast-plus. Antigenic sites for AR and ER were immunolocalized using PG-21 rabbit antirat/human antibody and H-222 rat antihuman monoclonal antibody, respectively. The avidin-biotin horseradish peroxidase procedure was used to identify positive immunoreactivity. Negative controls included incubation of sections with irrelevant IgG in place of primary antibody. RESULTS: In intact animals, whereas AR were found in epithelial, connective tissue, and peritubular smooth muscle cells of the efferent ductules, regions I-V of the epididymis, and ductus deferens, ER were confined to nonciliated cells of the efferent ductules. Bilateral orchidectomy caused a severe loss of both AR and ER staining. Testosterone replacement to orchidectomized animals restored staining of both AR and ER to the intact level. Neither unilateral ligation of the extratesticular rete nor unilateral orchidectomy had any effect on AR or ER immunostaining. CONCLUSION: Circulating androgen alone, without any input from luminal androgen or other rete fluid contents, can regulate expression of both androgen receptor and estrogen receptor.

Animals↗

PubMed1998

Ovary-independent estrogen receptor expression in neonatal porcine endometrium.

Effects of age and ovariectomy (OVX) at birth on uterine growth, endometrial development, and estrogen receptor (ER) expression were determined for intact and OVX gilts (n = 5 per day) hysterectomized on postnatal days (PND) 0, 15, 30, 60, 90, or 120. Uteri were evaluated histologically, and ER protein and mRNA expression were characterized immunohistochemically and by in situ hybridization. OVX did not affect uterine weight or endometrial thickness until after PND 60, when both increased more rapidly in intact gilts. Neither did it affect genesis of uterine glands, which were present and which proliferated after PND 0, or endometrial ER expression patterns in glandular epithelium (GE), luminal epithelium (LE), or stroma (S) between PND 0 and 120. Endometrium was ER negative at birth. On PND 15, the ER signal was strong in GE, weak in S, and effectively absent in LE. Thereafter, although the ER signal remained strong in GE and increased through PND 60 in S, it was not evident consistently until after PND 30 in LE. The data indicate that 1) porcine uterine growth and endometrial morphogenesis are ovary-independent processes before PND 60; 2) uterine gland genesis is associated temporally with development of ER-positive endometrial GE and S; and 3) regulation of endometrial ER expression is ovary independent between PND 0 and 120. The results establish the ER as a marker of GE differentiation and implicate this receptor in mechanisms regulating endometrial morphogenesis in the neonatal pig.

Aging↗

PubMed1998

Keratinocyte growth factor expression by the bovine corpus luteum.

Communication between cells of the corpus luteum (CL) is thought to be necessary for normal luteal function. Keratinocyte growth factor (KGF) is produced by mesenchymally derived cells in numerous tissues and acts on epithelial cells. In bovine follicles, theca cells produce KGF, which can stimulate granulosa cell proliferation. Whether KGF is produced by ovarian cells after luteinization is unknown. Our objective was to determine whether KGF mRNA and protein were present in bovine luteal tissue, and if so, to determine what type(s) of luteal cells contains KGF. CL (n = 3-4/day) were obtained from specific days throughout diestrus. Presence of KGF mRNA in CL was determined using a porcine KGF anti-sense cRNA probe. Northern analyses of luteal tissue poly(A)+ RNA revealed a single transcript (approximately 2.0 kilobases), the quantity of which did not change throughout diestrus. Western analysis revealed an immunoreactive band (28 kDa) in luteal tissues and theca cell homogenates that was absent from granulosa cell homogenates. Immunocytochemistry showed KGF predominantly in theca and small luteal cells. Results indicate that bovine CL produce and contain KGF, which is primarily localized in small luteal cells. Therefore, KGF may participate in paracrine communication within the bovine CL.

Animals↗

PubMed1998

Effects of the estrous cycle and early pregnancy on uterine expression of Mx protein in sheep (Ovis aries).

Conceptuses of ruminant ungulates produce large amounts of a type I interferon, interferon-tau (IFNtau), which is the signal for maternal recognition of pregnancy. Induction of cellular Mx proteins is an important component of the response to type I interferon in the immune system, but Mx regulation and function have not been studied in the uterus. This study examined temporal and spatial alterations in ovine uterine Mx expression during the cycle and early pregnancy using immunohistochemistry, in situ hybridization, and Northern and slot-blot analysis. Sheep uterine endometrium expressed a single approximately 2.5-kilobase Mx mRNA transcript that was detectable at all stages of the estrous cycle and early pregnancy examined. In cyclic ewes, mRNA abundance in endometrium increased from Day 1 to peak levels at Day 13 and then declined to Day 15. In pregnant ewes, steady-state levels of Mx mRNA were first detected above the level in cyclic ewes at Day 13 postmating, were greater than 10-fold higher at Day 15, and remained elevated at Day 19. Expression of Mx mRNA in the myometrium did not change during the estrous cycle but increased approximately 23-fold between Days 11 and 15 of pregnancy. Immunohistochemical and in situ hybridization analysis revealed a similar temporal pattern of Mx expression. In cyclic ewes, Mx protein and mRNA were initially localized to the luminal epithelium at Days 1 and 3, increased from Days 5 to 13, especially in the shallow uterine glands, and then declined at Day 15. Pregnancy resulted in up-regulation of Mx expression in the luminal and glandular epithelium, stroma, and myometrium. Punctate Mx immunostaining and Mx mRNA concentrations were greatest when progesterone production was maximal during the estrous cycle and were strongly up-regulated by the conceptus across the entire uterine wall. It is suggested that a cascade of induction of Mx gene expression proceeds from the luminal epithelium to the outer longitudinal myometrium and that transcriptional activation of the promoter may involve both soluble cytokines (i.e., IFNtau) and steroid hormones (i.e., progesterone).

Animals↗

PubMed1997

Immunolocalization of androgen receptor and estrogen receptor in the developing testis and excurrent ducts of goats.

BACKGROUND: Because of the significance of androgens and estrogens in prenatal and postanatal differentiation of the testis and excurrent ducts, it is important to understand the developmental pattern of androgen receptor (AR) and estrogen receptor (ER) in these organs. METHODS: Tissues from 1-23-week-old goats were fixed in 4% paraformaldehyde and embedded in Paraplast-plus. Antigenic sites for AR and ER were immunolocalized using the PG-21 rabbit anti-rat/human antibody and the H-222 rat anti-human monoclonal antibody, respectively. The avidin-biotin horseradish peroxidase procedure was used to identify positive immunoreactivity. Controls included incubation of sections with irrelevant IgG in place of primary antibody. RESULTS: Within the testis, immunostaining for AR in the nuclei of Sertoli cells increased gradually from mild at week 1 to strong at week > or = 19. In contrast, nuclei of peritubular myoid cells and Leydig cells exhibited moderate to strong reaction for AR in all animals. Germ cells were negative. Within the rete testis, efferent ductules, regions I-V of the epididymis, and ductus deferens, nuclei of all epithelial cells, peritubular myoid cells, and intertubular connective tissue cells expressed moderate to strong staining for AR at all ages. ER were confined to nonciliated cells of the efferent ductules, which displayed moderate staining in all animals, beginning from week 1. CONCLUSIONS: Nuclear AR staining, found in all testicular cells (except germ cells) and excurrent duct cells examined, was observed to change in an age-related manner only in Sertoli cells, where staining intensity increased between week 1 and week 19. Staining for ER, confined to nonciliated epithelial cells of the efferent ductules, was not affected by postnatal age.

Animals↗

PubMed1997

Immunolocalization of receptors for androgen and estrogen in male caprine reproductive tissues: unique distribution of estrogen receptors in efferent ductule epithelium.

Androgens and estrogens affect physiological processes in the testis and male excurrent duct system. This study was designed to identify and characterize distribution of androgen receptors (AR) and estrogen receptors (ER) in the reproductive organs of the male goat. Tissues, including testis, efferent ductules, epididymis (regions I-V), and ductus deferens, were obtained from five mature Nubian goats, fixed in 4% paraformaldehyde, and embedded in paraplast. Antigenic sites for AR were unmasked by microwave treatment (four times, 5 min each) of tissue sections immersed in 10 mM citrate (pH 6) and were detected using the PG-21 rabbit anti-rat/human antibody. Antigenic sites for ER were identified using the H-222 rat anti-human monoclonal antibody after tissue sections were treated with pronase (0.5 mg/ml, 37 degrees C, 8 min). Avidin-biotin horseradish peroxidase procedures were used to identify positive immunoreactivity. Irrelevant IgG was substituted for primary antibody in negative controls. Positive nuclear immunostaining for AR was observed in all types of epithelial cells, peritubular smooth muscle cells, and intertubular fibroblasts of the intratesticular rete, efferent ductules, epididymis (regions I-V), and ductus deferens, as well as in Sertoli, Leydig, and peritubular myoid cells and intertubular fibroblasts of the testis. In contrast, nuclear immunostaining for ER was confined to nonciliated cells of the efferent ductules. Thus, AR-positive cells are ubiquitously distributed in caprine testicular and excurrent ductular tissues, and ER-positive cells are unique to the efferent ductules. The caprine model should be useful in studies designed to determine mechanisms through which androgens and estrogens regulate development and function of the testes and excurrent ducts.

Animals↗

PubMed1997

Comparative study of uterine morphogenesis and protein secretion in neonatal White crossbred and Meishan gilts.

Thirty-five crossbred and 22 Meishan contemporary gilts were necropsied on Day 1, 14, 28, 42, or 56 of age (birth = Day 0). At necropsy, a cross section of one uterine horn was fixed for histomorphometric study, and minced uterine tissue was cultured with 50 muCi [3H]leucine. Secreted proteins were identified by two-dimensional PAGE, fluorography, and incorporation of radioactivity. Body weights at necropsy were similar for the two breeds and increased (p < 0.01) between Days 1 and 56 of age. Ovarian and uterine weights, as well as histomorphometric areas, were similar for the two breeds on Day 1 but increased markedly (p < 0.01) in Meishan gilts on Day 56. In gilts of both breeds, secretion of uterine proteins 1 (M(r) x 10(-3)/pI; 45/6.0), 2a and 2b (doublet, 25/6.2), and 3 (20/5.5) increased in association with endometrial gland development. A fourth protein (97/4.0) was observed in gilts of both breeds but was more abundant in Meishan; a fifth protein (13/6.0) was detected only in crossbred gilts on Day 56. Although specific regulatory roles for locally produced uterine proteins remain to be defined, the increase in specific uterine proteins and breed differences in uterine protein secretion suggest that uterine proteins may influence early uterine development.

Age Factors↗

PubMed1997

Effects of stage of gestation and uterine ligation on ovine placentome development and glycosaminoglycans.

Effects of restricting uterine space on physical, biochemical, and histochemical characteristics of ovine placental tissues were studied. Ewes (n = 20) were unilaterally ovariectomized, assigned to either control (C; n = 10) or unilateral (UPx; n = 10) pregnancy groups, mated (d 0), and hysterectomized on either d 60, 90, or 120. Placental and fetal weights and placentome wet weights (PWT) in three placental areas (AI, AII, AIII) were recorded. Placentome tissue concentrations of RNA, DNA, hyaluronic acid (HA), and protein (TP) were determined. Overall, placentome numbers were reduced (P < .02) 23%, but individual PWT increased (P < .05) 27% in UPx ewes. In UPx ewes, neither total placental nor placentome weights, fetal weights, fetal crown-rump lengths, nor PWT:fetal weight ratios were affected by treatment (Trt). In the C and UPx groups, PWT increased (P < .01) from d 60 to 90. However, compensatory growth was confined to placental areas AII and AIII in UPx groups (treatment x area, P < .01). Treatment did not affect concentrations of RNA, DNA, TP, or HA. However, RNA, DNA, and TP increased from d 60 to 120 (P < .01), but HA decreased (P < .01). Histologically, placentome cellularity increased from d 60 to 120 as area occupied by individual fetal chorioallantoic villi (FV) decreased. The FV stained with Alcian Blue 8X. Alcianophilia was attenuated at low pH and eliminated by pretreatment with hyaluronidase, indicating the presence of HA. Thus, increased placentomal cellularity was accompanied by loss of HA from fetal allantoic mesenchyme. Mechanisms regulating loss of HA from FV may support placental maturation and fetal growth.

Animals↗

PubMed1995

Neonatal exposure to progesterone and estradiol alters uterine morphology and luminal protein content in adult beef heifers.

Exposure of the developing urogenital tract to steroids can affect structure and function of adult tissues and compromise reproductive performance. This study was conducted to determine 1) if exposure of neonatal heifer calves to progesterone (P) and estradiol benzoate (E), delivered from a commercial growth-promoting implant, would affect adult uterine morphology or uterine luminal protein content; and 2) whether such effects would be related to neonatal age at the first exposure. At birth (Day 0), 20 crossbred beef heifers were assigned to 1 of 4 treatment groups (n = 5 per group), defined by age at implant placement. Heifers either received an implant on Days 0, 21 or 45, or served as untreated controls. The heifers were maintained together and slaughtered at 15 mo of age, during the luteal phase of an induced estrous cycle, when reproductive tracts and blood samples were obtained. Peripheral plasma P concentrations were determined by RIA. Uterocervical wet weights were recorded, and uterine luminal flushings (ULF) were assayed for total protein. Cross-sections of uterine tissues were evaluated histomorphometrically to determine myometrial and endometrial areas and relative endometrial gland density. Treatment did not affect plasma P concentrations (3.2 +/- 0.5 ng/ml). Regardless of age at treatment, neonatal PE exposure reduced uterocervical wet weight by 35% (112.8 < 173.9 +/- 13.9 g; P < 0.01), myometrial area by 23% (125.3 < 162.8 +/- 8.5 mm2; P < 0.02), and endometrial area by 27% (33.3 < 45.4 +/- 2.7 mm2; P < 0.09) compared with the untreated controls. Endometrial gland density was reduced (P < 0.01) by 40% in treated heifers. This effect was related to age at implant placement. Uterine gland density was reduced (P < 0.01) by 65% in heifers treated at birth, while reductions of 22 and 33% were observed for heifers treated on neonatal Day 21 or 45, respectively. Consistently, ULF protein content was lower (P < 0.01) in the treated heifers (2.67 < 4.98 +/-. 72 mg/ULF). Thus, exposure of newborn calves to PE can have profound effects on adult uterine morphology and environment, the extent of which may depend upon the developmental period when exposure occurs. The potential of such alterations to affect reproductive performance in adult beef heifers remains to be investigated.

Journal Article↗