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R D Geisert

Publications and source records attributed to R D Geisert.

At least 73 records · Page 4Linked to original sources
PubMed1990

Identification and characterization of bovine oviductal glycoproteins synthesized at estrus.

Published reports indicate that in several mammalian species the oviduct synthesizes and secretes specific glycoproteins which are components of the luminal fluids at the time of ovulation and fertilization. The present study characterized the secretory glycoproteins synthesized by the bovine oviduct at estrus. Oviducts obtained from four crossbred cows in estrus were flushed with saline, and segments of the ampullary and isthmic regions were fixed for immunocytochemical analyses. The remainder of the tissue was subjected to explant culture for 24 h in medium containing either 3H-leucine or 3H-glucosamine. Analysis of culture media by one- and two-dimensional SDS-PAGE followed by fluorography indicated that both the ampullary and isthmic regions synthesized a major class of Mr 97,000 glycoproteins with isoelectric points ranging from 5.5 to 8.1. A polyclonal antibody was generated to the glycoproteins after their isolation by gel filtration followed by electrophoretic separation. Western blot analysis of oviductal culture media indicated that the antisera cross-reacted with a doublet at Mr 97,000 and to a lesser extent with two additional bands at Mr greater than 200,000. Immunoreactive antigens were not identified in serum or in culture media of ovary, uterus, and nonreproductive tract tissues. The Mr 97,000 glycoproteins were present in oviductal flushings obtained from cows in estrus. They were also detected to a lesser degree in oviductal flushings obtained from cows at Days 5, 10, 15, and 18 of the estrous cycle, with the least amount of immunoreactivity being observed in Day 10 samples.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Nutrition, body condition and reproduction in beef cows: fetal and placental development, and estrogens and progesterone in plasma.

Mature, pregnant Hereford cows (n = 17) were used to determine the effect of nutrition and body energy reserves on fetal development, concentrations of nutrients and estrogens in placental fluids, and on progesterone, estrogens and placental lactogen in maternal plasma. On d 145 of gestation, cows were assigned by breeding date to two groups and fed to achieve either a thin (TH; n = 8) or a moderate (M; n = 9) body condition score (BCS) by d 195 of gestation. Body weights, BCS, estrogens, placental lactogen and progesterone in plasma were determined weekly between d 200 and 256 of gestation. Cows were slaughtered on d 259 +/- 1 of gestation, and amnionic and allantoic fluids were sampled and analyzed for concentrations of protein, fructose and estrogens. Body weights and BCS were less (P less than .01) for TH (419 kg; 3.7) than for M (511 kg; 5.7) cows at slaughter. Uterine weights were less (P less than .07), but chorioallantoic weights were greater (P less than .07) in TH than in M cows. Cotyledonary weights were greater (P less than .05) for TH than for M cows, and total fructose in amnionic fluid was reduced (P less than .01) in TH compared with M cows. Concentrations of estradiol, estrone and placental lactogen were greater between d 240 and 256 of gestation for TH than for M cows. We conclude that nutrient intake and(or) BCS of beef cows during late gestation influence placental weight, fructose in amnionic fluid, and placental lactogen, estrone and estradiol in plasma.

Allantois↗
PubMed1990

Embryonic steroids and the establishment of pregnancy in pigs.

In the pig, establishment of pregnancy begins about 11-12 days after the start of oestrus. The ability of pig conceptuses to synthesize and release oestrogens during this period, as well as the ability of exogenous oestrogens to induce pseudo-pregnancy when administered from Day 11-15 of the oestrous cycle, provide evidence for an involvement of oestrogen in the maternal recognition of pregnancy in the sow. Oestrogen derived from the conceptus or from administration to cyclic gilts stimulates uterine secretion of calcium and specific polypeptides on Day 11-12. The specific roles for the uterine secretory response to oestrogen in the maintenance of pregnancy are unknown. However, it has been proposed that oestrogen prevents luteolysis in the sow through reorientation of endometrial prostaglandin release, i.e. into the uterine lumen rather than into the uterine vasculature. Oestrogen may interact with prolactin and/or conceptus secretory proteins to shift the direction of prostaglandin movement. Although conceptus oestrogen synthesis triggers a number of uterine secretory events on Day 11, a second sustained phase of oestrogen stimulation from Day 14 to 18 appears to be necessary for luteal maintenance beyond Day 25. Pig conceptuses synthesize and release large amounts of oestrogens between Days 14 and 18 of pregnancy. Conceptus oestrogens are clearly involved with the establishment of pregnancy. However, the conceptus also secretes a number of biologically active substances such as catechol oestrogens, prostaglandins and polypeptides which could interact with oestrogen to prevent luteolysis. The roles of these factors in control of vascular permeability, blood flow, placental attachment and immunological protection certainly indicate that, in addition to oestrogens, other factors are involved in the establishment of pregnancy in pigs.

Animals↗
PubMed1989

Uterine secretory alterations coincident with embryonic mortality in the gilt after exogenous estrogen administration.

Sixteen crossbred gilts were assigned randomly to receive either an i.m. injection of sesame oil (control) or estrogen (E), 5 mg of estradiol valerate, on d 9 and 10 of pregnancy. Gilts were unilaterally hysterectomized on either d 12 and 14 or 16 and 18. Uterine horns were flushed with 20 ml of .9% sterile NaCl solution to recover conceptus tissue. Conceptuses and endometrial explants were cultured for 24 h with 100 microCi [3H] leucine in 15 ml of minimum essential media. After dialysis, culture media were submitted to 2D-polyacrylamide gel electrophoresis and incorporated proteins were analyzed by fluorography. Normal, intact conceptus tissue was recovered from control gilts. Estrogen-treated gilts flushed on d 12 and 14 contained intact conceptuses; however, uteri from two gilts on d 16 and three on d 18 contained degenerating conceptus tissue. Comparison of endometrial polypeptides synthesized in vitro indicated an alteration in E-treated gilts on d 12 through 18. Although similar polypeptides were present, a band of polypeptides with a Mr of approximately 30,000 and pI from 7.9 to 8.9 and a larger, acidic polypeptide (Mr = 100,000, pI 3.5 to 5.0) were faint or absent in E-treated gilts. Conceptuses elongated normally in the altered uterine environment, but failed to survive past d 14 in E-treated gilts. Although loss of specific polypeptides in E-treated gilts coincides with conceptus death, their function in conceptus development or attachment is unknown.

Abortion, Veterinary↗
PubMed1988

Effect of exogenous progesterone on prostaglandin F2 alpha release and the interestrous interval in the bovine.

The present study was developed to determine if administration of progesterone, early in the estrous cycle of the cow, stimulated an advanced pulsatile release of PGF2 alpha from the uterine endometrium resulting in a decreased interestrous interval. Twenty-three cyclic beef cows were randomly assigned to receive either sesame oil or progesterone (100 mg) on Day 1, 2, 3 and 4 of the estrous cycle. Peripheral plasma concentrations of progesterone and the metabolite of prostaglandin F2 alpha, 15-keto-13,14-dihydro-prostaglandin F2 alpha (PGFM) were measured by radioimmunoassay. Administration of exogenous progesterone increased peripheral plasma concentration of progesterone in treated (3.67 ng/ml) compared to control (1.28 ng/ml) cows from Day 2 through 5 of the estrous cycle. Progesterone administration shortened the interestrous interval (16.7 d) compared to controls (21.6 d). The shortened interestrous intervals in treated cows resulted from an earlier decline in peripheral plasma progesterone. Decline of peripheral plasma progesterone concentrations is coincident with an increased pulsatile release of PGFM in both progesterone treated and control cows. Results indicate that administration of exogenous progesterone stimulates an earlier maturation of endometrial development, causing an advanced release of PGF2 alpha which shortens the interestrous interval of the cow.

Animals↗
PubMed1988

Influence of Synchro-Mate-B and breed composition on estrous response and pregnancy rate in spring- and fall-bred Brahman crossbred beef cows.

Estrous response, pregnancy rate, and the relationship between palpable corpora lutea (CL) and plasma progesterone concentrations were studied during the spring (n = 149) and fall (n = 146) breeding seasons using postpartum, crossbred beef cows consisting of 0-Brahman, 1 4 - Brahman , or 1 2 Brahman breeding. At the start of each breeding season, a jugular blood sample was collected for progesterone analysis; each cow was palpated for the presence of a CL and randomly alloted within breed to a non-treated control or Synchro-Mate-B (SMB) treatment. Fewer (P<0.01) fall than spring bred cows exhibited estrus within the first 21 d of breeding. Within 48 h of implant removal, 84 and 64% (spring and fall, respectively) of synchronized cows exhibited estrus. In both seasons, more SMB than control cows became pregnant by 7 d of breeding. Percentage of Brahman breeding did not influence estrous response or pregnancy rate. On the basis of 292 evaluations, palpation per rectum correctly assessed ovarian status 74% of the time. These data indicate that although season can influence response. SMB can be used effectively to synchronize Brahman crossbred cows. In addition, it was found that there is a close relationship between palpation per rectum and plasma concentrations of progesterone.

Journal Article↗
PubMed1988

Estrogen-induced pseudopregnancy in gilts: Its use in estrus synchronization and subsequent influence on litter response.

The effectiveness of using estrogen-induced pseudopregnancy followed by PGF(2alpha) (Lutalyse) treatment to synchronize estrus in gilts and the subsequent effect of pseudopregnancy on litter parameters was examined in two experiments. Experiment 1 consisted of a control (n = 49) group and a pseudopregnant (n = 49) group. Pseudopregnant gilts received PGF(2alpha) between Days 25 and 38 and were bred at the ensuing estrus. Ninety-two percent of the gilts responded to PGF(2alpha) and exhibited estrus in 4.9 +/- 0.2 (Least Square Mean +/- SEM) days. Duration of estrus was longer in pseudopregnant compared to control gilts (2.8 vs 1.7 d, P<0.001). Experiment 2 consisted of a control (n = 24) group and a pseudopregnant (n = 24) group. All pseudopregnant gilts received PGF(2alpha) on Day 38 and 79% responded with a mean onset of estrus at 5.2 +/- 0.2 d. As in Experiment 1, duration of estrus was longer in gilts from the pseudopregnant group (2.2 vs 1.7 d, P<0.005). The percentage of farrowing was similar for both groups in both experiments, and no differences existed in the number of pigs born and those alive at 21 d post partum. Litters from gilts in the pseudopregnant groups were heavier at birth than those in the control group (Experiment 1, 17.21 vs 15.25 kg, P<0.01; Experiment 2, 15.31 vs 13.55 kg, P<0.02) and at 21 d (Experiment 1, 60.81 vs 56.79 kg, P<0.01; Experiment 2, 51.89 vs 46.96 kg, P<0.02). Survival rate at 21 d was higher in offspring from pseudopregnant gilts in both experiments (Experiment 1, 85.3% vs 78.2%, Experiment 2, 91.4% vs 81.2%).

Journal Article↗
PubMed1988

Effect of heat stress on conceptus and uterine secretion in the bovine.

This study examined the effects of heat stress on conceptus secretion of bovine trophoblastic proteins (bTP) and the uterine secretory environment on Day 17 of pregnancy. After mating to fertile bulls, cows were placed in an environmental chamber at 21 degrees C, 45% RH on Day 7 and were assigned to one of the following treatments on Day 8: Control (21 degrees C, 45% RH), Treatment 1 (37 degrees C, 30% RH) and Treatment 2 (37 degrees C, 40% RH). Cows were slaughtered on Day 17 and each uterine horn was flushed separately with physiological saline to recover the conceptus and uterine contents. The wet weight of the conceptus was recorded and uterine flushings were analyzed for quantitative and qualitative protein changes, prostaglandin F and calcium concentrations. Conceptus tissue was cultured in vitro with 100 muCi of [(3)H]-leucine and the polypeptides released into the medium were analyzed by 2D-PAGE followed by fluorography. Heat stress increased rectal temperature of cows and reduced conceptus wet weight. Uterine content of protein and calcium were increased in the uterine horn ipsilateral to the CL of heat-stressed cows. Although uterine protein increased in heat-stressed cows, no qualitative difference was observed in the polypeptides present in the uterine lumen. Conceptus synthesis and release of bTP were enhanced in treated cows. These responses indicate that heat stress between Days 8 to 17 of pregnancy altered the uterine environment as well as growth and secretory activity of the conceptus.

Journal Article↗
PubMed1988

Evidence for maternal regulation of early conceptus growth and development in beef cattle.

Fifty-one cyclic beef cows were mated with fertile bulls. At 36 h after the start of oestrus, cows were assigned to receive sesame oil (controls) or progesterone (100 mg) on Days 1, 2, 3 and 4 of pregnancy. Peripheral plasma concentration of progesterone was measured until slaughter on Days 5 or 14. Cows were randomly assigned to be slaughtered on Days 5 or 14 or remain intact and palpated per rectum on Day 40 to verify pregnancy. Uteri on Days 5 and 14 were flushed for recovery of luminal protein and conceptus tissue. Conceptus and endometrial tissues were cultured with [3H]leucine and submitted to two-dimensional-PAGE and fluorography. Administration of progesterone increased peripheral plasma progesterone concentration on Day 2-5. Conceptuses recovered from progesterone-treated cows on Day 14 were advanced in development compared to conceptuses from control cows. Conceptuses recovered from progesterone-treated cows were viable as polypeptides associated with maintenance of pregnancy in cattle were synthesized and released at an earlier time and pregnancy was maintained beyond Day 40. Early progesterone stimulation altered the synthesis and release of polypeptides from endometrial explant cultures on Day 5. Results indicate a role of progesterone in the maternal regulation of conceptus growth and development in early pregnancy of cattle.

Animals↗
PubMed1987

Length of pseudopregnancy and pattern of uterine protein release as influenced by time and duration of oestrogen administration in the pig.

Treatment of gilts with 5 mg oestradiol benzoate on Day 9.5, 11, 12.5, 14, 15.5 or Days 14-16 resulted in an interoestrous interval of about 30 days. Administration of oestradiol benzoate daily from Days 11 to 15 or two periods of treatment on Days 11 and 14 to 16 resulted in prolonging CL function beyond 60 days from the pre-treatment oestrus. Endometrial secretory response to oestrogen stimulation, based on the ability of oestrogen to release calcium and uterine protein into the lumen appears to occur after Day 10 of the oestrous cycle. The results suggest that maintenance of prolonged CL function appears to require two periods of oestrogen stimulation. The first period occurs on Day 11 when the endometrium has become responsive to oestrogen stimulation followed by a second prolonged increase in oestrogen stimulation after Day 14. These findings accord with the normal patterns of oestrogen released by pig blastocysts during early pregnancy.

Animals↗
PubMed1987

Development of pig blastocysts in a uterine environment advanced by exogenous oestrogen.

Routine embryo transfer techniques were used to establish recipient groups in which blastocysts were either asynchronous (blastocysts 24 h behind recipient uterus) or synchronous with their uterine environment. Oestradiol valerate (5 mg) was administered on Day 11 of the recipient's cycle to stimulate release of uterine secretion in the synchronous gilts (Group SE) and one group (AE) of asynchronous gilts. The gilts in the other asynchronous group (Group AC) were injected with vehicle (sesame oil). Embryos recovered on Day 14 by hysterectomy and flushing were evaluated for morphological development. Oestradiol treatment resulted in a failure of blastocyst development in Group AE gilts only. Recoverable oestradiol in the uterine flushings was increased in gilts in Groups AC and SE which contained elongated blastocysts. Plasmin inhibitor levels were lower in Groups AC and SE while PGF tended to be increased. Acid phosphatase activity was higher and recoverable Ca2+ was lower in Groups AE and SE. Failure of blastocyst development in Group AE is believed to have resulted from a failure to undergo trophoblastic elongation due to premature alteration of the uterine environment at a critical period of blastocyst development or from the presence of an unfavourable uterine environment for blastocyst attachment and development shortly after Day 12.

Acid Phosphatase↗
PubMed1987

Development and survival of pig blastocysts after oestrogen administration on day 9 or days 9 and 10 of pregnancy.

In Exp. 1, administration of 5 mg oestradiol valerate i.m. to pregnant gilts on Days 9 or 9 and 10 advanced the uterine secretion of calcium, protein, and acid phosphatase as demonstrated by levels recovered in the uterine flushings of females unilaterally hysterectomized on Day 11. Upon removal of the remaining uterine horn on Day 12, protein and acid phosphatase increased while Ca2+ decreased in oestradiol-treated gilts as did PGF. In contrast, a 4-fold increase in recoverable Ca2+ occurred from Days 11 to 12 in control gilts. Recoverable oestradiol-17 beta was increased in all 3 groups on Day 12 and plasmin inhibitor concentration increased in oestradiol-treated gilts. Two-dimensional PAGE demonstrated the appearance of a group of very acidic polypeptides in oestradiol-treated gilts. Blastocysts recovered from the second uterine horn had undergone elongation to the filamentous morphology in all 3 groups. In Exp. 2, oestradiol valerate was administered to pregnant gilts on Day 9 or Days 9 and 10 followed by total hysterectomy on Day 16. No differences in recoverable Ca2+ or protein were found, but acid phosphatase was decreased by 75% after oestradiol treatment. Recoverable oestradiol was decreased in oestradiol-treated gilts while PGF and plasmin inhibitor concentrations were unaffected. Compared with the control gilts, blastocysts recovered from oestradiol-treated gilts were fragmented and degenerating on Day 16. PAGE demonstrated greatly intensified staining of the group of acidic polypeptides in oestradiol-treated gilts. These results indicate that oestradiol treatment on Day 9 of pregnancy advances uterine secretory response, but that blastocyst elongation can occur in this uterine environment and in the presence of declining intraluminal Ca2+ levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Phosphatase↗
PubMed1987

Effect of heat stress on early embryonic development in the beef cow.

Hereford and Hereford X Angus cows (n = 31) were utilized to determine the effects of heat stress on early embryonic development and survival. After acclimation to handling, cows were cannulated via the jugular vein on d 7 and assigned to either a control (C) chamber environment of 22 C, 35% relative humidity (RH) or one of two heat stress treatments. Ambient temperature was maintained at 37 C for 12 h followed by a decrease to 33 C for the remainder of the day in both treatment groups. Relative humidity was maintained at 27% in treatment 1 (TRT 1) and 38% in treatment 2 (TRT 2). On d 8 to 16, daily measurements of respiration rate (RES), rectal temperature (REC) and water intake were taken along with samples of blood, which were analyzed for hematocrit (HEM) and plasma concentration of protein (PP), progesterone (P4), estradiol-17 beta (E2), thyroxine (T4) and glucose (GLU). The uterus was recovered and flushed with saline on d 17 to recover the conceptus and uterine contents. Conceptus (if present) and corpus luteum (CL) wet weight were determined. Cows subjected to TRT 2 had increased RES and REC (P less than .01), while HEM was decreased (P less than .05) compared with C cows. Plasma T4 concentration was decreased (P less than .10) in TRT 2 compared with TRT 1 and cows, while P4 concentration were not significantly different. Corpora lutea wet weights were reduced (P less than .10) in heat-stressed cows vs C cows.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Role of prostaglandins in development of porcine blastocysts.

Rapid elongation of porcine blastocysts between Days 11 to 12 of pregnancy coincides with an increase in uterine luminal content of prostaglandins. The present study evaluated the effect of two prostaglandin synthesis inhibitors (indomethacin and flunixin meglumine) on elongation of porcine blastocysts from spherical to filamentous forms between Day 11 to 12 of pregnancy. Gilts were hemi-hysterectomized on Day 11 of pregnancy. The excised uterine horn was flushed with 0.9% saline and diameter of blastocysts recovered were measured. Immediately following surgery, pregnant gilts were assigned to receive either: 1) vehicle every 4 h, 2) flunixin meglumine (banamine) every 4 h, or 3) indomethacin every 12 h. The remaining uterine horn was removed and flushed after the time of blastocyst elongation estimated for each gilt on basis of blastocyst development in the first horn. Uterine flushings were analyzed for total calcium, protein, acid phosphatase activity, estrone, estradiol-17 beta and prostaglandin F. Pretreatment blastocyst diameter was similar for all groups and ranged from 1 mm to 20 mm. Treatment of gilts with either banamine or indomethacin effectively inhibited (P less than 0.001) the increase in uterine luminal content of PGF. Total calcium, estrone and estradiol-17 beta were not influenced by treatment. Total uterine luminal protein and acid phosphatase activity were reduced (P less than 0.05) in banamine treated gilts compared to those receiving vehicle or indomethacin treatments. Although total PGF recovered in uterine flushings was reduced during the period of blastocyst elongation, treatment with PGF synthetase inhibitors failed to block rapid elongation of blastocysts from the spherical to filamentous forms.

Animals↗
PubMed1985

Differential patterns of secretory protein localization within the pig uterine endometrium.

We have compared the distribution of two of the major secreted proteins of the porcine uterus within the endometrium of ovariectomized pigs which had received hormone replacement therapy for 30 days. The proteins studied, plasmin/trypsin inhibitor (PI) and uteroferrin (Uf), an iron-containing acid phosphatase, were both secreted into the uterine lumen by ovariectomized gilts given progesterone (P4) or P4 and 17 beta-estradiol but not by animals given 17 beta-estradiol alone or corn oil. The two proteins were localized immunocytochemically within the endometrium using an immunoperoxidase procedure. The results confirmed that production of PI and Uf was P4-dependent and demonstrated that the primary site of synthesis of PI was the surface and upper glandular epithelium, while Uf synthesis was confined to the glandular epithelium. A similar localization of PI and of Uf was found in endometrial tissue from pigs at day 13 (late luteal phase) of the estrous cycle. These results suggest that the uterine epithelium of the pig is regionally differentiated with regard to the production of P4-induced proteins.

Acid Phosphatase↗
PubMed1984

H1 histone synthesis by implanting pig blastocysts.

Histones were isolated from pig conceptuses on Days 8-18 of pregnancy, Acid-urea polyacrylamide gel electrophoresis (PAGE) was performed on samples of total histone and on PCA-soluble histone fractions (primarily histone H1). Conceptuses were also incubated for 24 h in vitro in the presence of [3H]lysine, and the histones analysed by autofluorography after PAGE. A minimum of two H1 histone bands was resolved in stained gels by these techniques. The autofluorographs indicate that both H1 histones are synthesized throughout the developmental period analysed. No shift in H1 histone subtype, as encountered in sea urchin development, was observed. The results suggest that such a shift, if it occurs, may have been made before Day 8.

Animals↗
PubMed1983

Relationship between release of plasminogen activator and estrogen by blastocysts and secretion of plasmin inhibitor by uterine endometrium in the pregnant pig.

Pig blastocysts isolated between Days 10 and 16 of pregnancy release the protease, plasminogen activator (PA), into the medium in a time-dependent manner when cultured in vitro. Production is biphasic. The initial phase (Days 10-12) coincides with the early elongation stages, while release during the second phase (Days 14-16) occurs during a time at which the DNA content of the blastocysts is increasing markedly. Uterine flushings from these pregnant animals contain the zymogen substrate for PA, plasminogen, presumably as a serum transudate. Plasminogen is present in highest amounts at Day 12. The blastocyst, therefore, has the potential ability to generate the broadly specific protease, plasmin, within the uterine lumen. However, during this same period, the endometrium secretes an inhibitor of plasmin into the uterine lumen. In pregnant animals the amount of plasmin inhibitory activity rose 7-fold between Day 10.5, when the blastocysts were spherical, and Day 12, when they had become filamentous. At Day 12 each uterine horn contained about 3 to 4 mg of plasmin inhibitor. A similar release of inhibitor can be initiated in nonpregnant gilts given a single, intramuscular injection of estradiol valerate on Day 11 of the estrous cycle. It is suggested that the initiation of estrogen production by the elongating blastocyst triggers the release of plasmin inhibitor by the maternal endometrium and that the inhibitor serves to prevent a proteolytic cascade of reactions initiated by blastocyst PA, which might otherwise damage the uterine epithelium.

Animals↗