SEARCH · PubMed Health

Results for “Progesterone--indications”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

PubMed1975

Progesterone synthesis in developing rabbit corpora lutea in the absence of follicular estrogens.

We have investigated the role of 17beta-estradiol in the early development of the rabbit corpus luteum. Ectopic corpora lutea were established in all animals by autotransplanting preovulatory follicles beneath the kidney capsule 6.5 to 8 h after mating (day 0). At this time, the rabbits were bilaterally ovariectomized and in some of these rabbits a Silastic capsule containing crystalline 17beta-estradiol was implanted SC. Mean serum concentration of estradiol in rabbits with an estradiol impant was 16.4 pg/ml. In rabbits without an estradiol implant, the estradiol concentration averaged 1 pg/ml despite the presence of transplanted luteinized follicles. Daily blood samples were analyzed for progesterone by radioimmunoassay. Ectopic corpora lutea developed in rabbits with or without estradiol treatment. Serum progesterone concentrations in the two groups increased above castrate values and were not significantly different from one another through day 5. After day 5, progesterone concentrations steadily increased in rabbits treated with estradiol and reached a value of 4.8 ng/ml by day 10. In contrast serum progesterone steadily decreased after day 5 in rabbits without estradiol treatment to a level of 450 pg/ml by day 10. Hysterectomy on day 0 did not prevent this decline in progesterone, indicating that a uterine luteolytic agent was not involved. Total luteal weight on day 10 was positively correlated with serum progesterone concentration (r equals .92; P greater than 0.01). These results indicate that for a period of approximately 5 days afte r ovulation, the development of the rabbit ectopic corpus luteum and the secretion of progesterone are autonomous from estradiol secreted by ovarian follicles. After this time, there is an absolute requirement for estrogen which permits further development of the corpus luteum and the continuation of progesterone synthesis.

Animals↗

PubMed1992

Modulation of mouse placental lactogen-I secretion in vitro: effects of progesterone and mouse placental lactogen-II.

The primary objective of this study was to develop a cell culture system for assessing effects of putative secretagogues on mouse PL-I (mPL-I) secretion. Trophoblast from days 7 to 11 of pregnancy was dispersed in collagenase, and the cells were fractionated on a Percoll gradient and plated on collagen gels in serum-free medium. Cells from days 7-9 of pregnancy yielded five bands on Percoll gradients and those from days 10 and 11 yielded six. mPL-I was present in four of the bands of cells from each day of pregnancy. Cells from day 7 of pregnancy that banded at a density of 1.044 g/ml secreted the largest amount of mPL-I during 5 days of culture. The mPL-I concentration of the medium of these cells increased for the first 3 or 4 days of culture and then declined on the fifth day. mPL-II could not be detected in the medium until the third or fourth day of culture, and its concentration increased thereafter. Cell viability was about 90% at the time of plating, remained at about 80% between days 1 and 4, and then declined on day 5. The cell type that produced mPL-I was identified with the reverse hemolytic plaque assay and by staining with anti-mPL-I antiserum. Both methods indicated that mPL-I was produced by giant cells. The ability of the cells to respond to putative secretagogues was examined using mPL-II and progesterone. mPL-II, at concentrations ranging between 10 ng/ml and 10 micrograms/ml, had no effect on the mPL-I concentration of the medium when it was present for up to 3 days of culture, which suggests that mPL-II does not inhibit mPL-I secretion in vitro. Incubation of the cells in the presence of 100-1000 ng/ml progesterone caused a dose- and time-dependent reduction in the mPL-I concentration of the medium and a decrease in the number of cells that stained with anti-mPL-I antiserum. The effect of progesterone on both endpoints was not apparent until the second day of treatment. These data suggest that progesterone inhibits mPL-I secretion at least in part by inhibiting the differentiation of mPL-I-producing giant cells. The fact that the mPL-I-producing cells responded to progesterone indicates that this culture system will be useful in assessing effects of putative secretagogues on mPL-I secretion.

Animals↗

PubMed1984

Daily hormonal changes in the maternal, fetal, and amniotic fluid compartments before parturition in a primate species.

The daily hormonal fluctuations that occur simultaneously in the fetus, mother, and amniotic fluid during late gestation and before preterm parturition were studied in long term catheterized rhesus macaques. Blood and amniotic fluid samples were collected twice daily and analyzed by RIA for estrone, estradiol, dehydroepiandrosterone sulfate (DHEAS), progesterone, cortisol, and prostaglandin F2 alpha metabolite (PGFM). Vaginal delivery in monkeys with live fetuses was preceded by rising concentrations of DHEAS in fetal, but not maternal, blood. Parallel increases in fetal plasma estrone, maternal plasma estrone and estradiol, and amniotic fluid estrone preceded the rise in amniotic fluid PGFM (P less than 0.005, by analysis of variance). Cortisol levels remained stable in maternal blood and amniotic fluid, but increased before delivery in fetal blood. Nocturnal progesterone peaks in both fetal and maternal blood increased progressively in magnitude in fetuses before parturition. Rising concentrations of fetal DHEAS, estrone, and progesterone indicated an increase in adrenal activity before parturition in the rhesus fetus. PG production, reflected in amniotic fluid PGFM concentrations, was temporally related to increasing amniotic fluid concentrations of estrone. Although progesterone withdrawal may occur at a local tissue level, parturition occurred without an apparent decrease in circulating maternal, circulating fetal, or amniotic fluid progesterone concentrations.

Amniotic Fluid↗

PubMed1975

Oestrogen-inducible uterine progesterone receptors. characteristics in the ovariectomized immature and adult hamster.

In order to characterize the uterine progesterone-binding proteins of oestrogen-primed and unprimed, ovariectomized immature and adult golden hamsters, cytosols were incubated with [3H]progesterone and/or other steroids and analyzed by sucrose-glycerol density gradient ultracentrifugation. Progesterone-binding components with sedimentation coefficients of 7S and 4.5S were found in the uterine cytosols, but not in the cytosols from the hypothalamus, pituitary, diaphragm, or small intestine. Oestradiol-17beta markedly elevated the level of 7S uterine receptor and this increase appeared to be due to new receptor synthesis, since actinomycin D and cycloheximide blocked this response. Fifty to 100 mug of oestradiol-17beta per kg body weight was found to promote a maximum increase in the 7S macromolecular component. The 7S receptor showed a tendency to saturate at 1 X 10(-7) M [1,2-3H]progesterone, indicating limited capacity. At a molar ratio of 100:1, unlabeled progesterone competed effectively for 7S and 4,5S [3H]progesterone binding, whereas 5alpha-pregnane-3,20-dione, oestradiol-17beta and testosterone did not. Moreover, [1,2-3H]cortisol and [1,2-3H]corticosterone did not bind to the 7S receptor, implying steroid specificity. CI-628, a non-steroid oestrogen antagonist, completely prevented [6,7-3H]oestradiol-17beta binding to its 8.5S uterine cytosol receptor, but was entirely without effect on 7S and 4.5S [3H]progesterone binding. Pronase, but not DNase or RNase, abolished 7S and 4.5S progesterone binding, suggesting that the binders are at least in part protein. Protamine sulphate and p-hydroxymercuribenzoate also obliterated 7S binding, implying that this receptor may be an acidic protein which contains sulfhydryl groups that are necessary for progesterone binding.

Animals↗

PubMed1983

An improved model of the distribution and metabolism of progesterone and 20 alpha-dihydroprogesterone in sheep.

When [3H]progesterone is infused intravenously into ewes, blood 20 alpha-dihydroprogesterone (20 alpha-diHP) becomes labelled and the changes in [3H]20 alpha-diHP activity with time are clearly related to that of [3H]progesterone. Concentrations of 20 alpha-diHP in blood have now been estimated for these experiments. During the infusion, the specific radioactivity of 20 alpha-diHP at steady state was only 53% of the specific radioactivity of progesterone, indicating that 20 alpha-diHP was produced other than by C-20 reduction of secreted progesterone. The change in blood concentration of 20 alpha-diHP during pregnancy in ewes suggests that the placenta is its source. [3H]20 alpha-dihydroprogesterone was infused into pregnant ewes and the specific radioactivity of 20 alpha-diHP measured during and after infusion. Together with information from earlier experiments when [3H]progesterone was infused, there is now sufficient data to estimate, without constraint, the parameters of a four-pool model describing the distribution and metabolism of progesterone and 20 alpha-dyhydro-progesterone in sheep.

20-alpha-Dihydroprogesterone↗

PubMed1984

Induction of plasma LH surges and normal luteal function in acyclic post-partum ewes by the pulsatile administration of LH-RH.

Plasma LH surges, similar to preovulatory surges in cyclic ewes (N = 9), were induced in 11/15 acyclic ewes, 19-26 days post partum, treated with LH-RH (100 ng i.v. every 3 h for 24 h, every 2 h for 24 h, then every 1 h for 24 h) (Group PPrh ), and in 11/15 LH-RH-treated acyclic ewes pretreated with progesterone (s.c. implant for 11 days) (Group PPprh ). Plasma progesterone, indicating subsequent luteal function, was detected in 10/11 Group PPrh ewes and in 9/11 Group PPprh ewes. The mean and peak plasma progesterone concentrations in these ewes were similar to those in cyclic ewes (2.0 +/- 0.2 and 3.1 +/- 0.4 ng/ml). The periods over which plasma progesterone was detected were similar in cyclic (11.7 +/- 0.5 days) and in Group PPprh ewes (12.2 +/- 0.8 days), but less in Group PPrh ewes (9.6 +/- 0.4 days). After regression of the induced corpus luteum more Group PPprh ewes (6/9) than Group PPrh ewes (2/10) showed oestrus and continued cycling. These results show that an appropriate pattern of pulsatile LH-RH treatment of post-partum acyclic ewes, pretreated with progesterone, can lead to plasma LH surges, luteal function, and subsequent ovarian cyclicity similar to that found in cyclic ewes. This suggests that ovarian acyclicity in post-partum ewes is a reflection of an inadequate pattern of pulsatile release of LH-RH from the hypothalamus.

Animals↗

PubMed1986

Determination of reproductive maturity in the female nine-banded armadillo (Dasypus novemcinctus).

At 3-month intervals from birth to 27 months of age, 3 female armadillos were killed. The number and size of follicles greater than 202 micron were determined, plasma progesterone concentration was measured, and values were correlated with age. Blood samples were taken monthly by femoral vein puncture and plasma was analysed by radioimmunoassay for progesterone concentration. At necropsy, both ovaries were visually inspected for a corpus luteum, weighed and then processed for routine histology. The number of normal, antral follicles greater than 202 micron were counted. These follicles were arbitrarily categorized into 15 different size groups (every 77 micron). Total number of follicles greater than 202 micron varied from 15.5 +/- 1.3 at 15 months of age to 26.3 +/- 1.9 at 21 months. Follicles of a size (greater than 978 micron) most likely to ovulate were present only at greater than or equal to 9 months of age. Progesterone values remained below the adult concentration (5 ng/ml) until 15 months of age. A concentration of progesterone indicative of ovulation (approximately 10 ng/ml) occurred between 17 and 20 months of age. The findings of the present study demonstrate that the female armadillo is reproductively mature after 15 months of age.

Animal Population Groups↗

PubMed1986

Steroid production and hCG binding by ram-induced ovarian follicles in seasonally anoestrous ewes.

The introduction of rams to a group of previously isolated anoestrous ewes has been shown to stimulate ovarian follicular development and ovulation. The present experiment was carried out to determine the ability of follicles arising from this ram stimulus to produce steroids and bind hCG. Seasonally anoestrous Southdown ewes were exposed to rams for 24 h, 40 h, 3 days, 10 days or 20 days before ovariectomy. Steroid production and the concentration of hCG binding sites in follicles dissected from the ovaries were measured in vitro. The presence of a ram caused ovulation and enhanced oestradiol production by follicles, but had little effect on total androgen production or the number of hCG binding sites present in the follicles when compared to follicles from anoestrous ewes. The oestradiol concentrations in large follicles were not as high as in preovulatory follicles from cyclic ewes reported in other studies. Follicles continued to develop through the ram contact period and when incubated after 40 h and 10 days of ram contact produced high levels of progesterone, indicating partial luteinization, although the corpora lutea (CL) resulting from the induced ovulations regressed prematurely. We suggest that the lack of hCG binding sites in ram-induced follicles may be the cause of poor luteinization and suboptimal development of luteal tissue after induced ovulation in ewes during seasonal anoestrus.

Anestrus↗

PubMed1990

Social suppression of ovarian cyclicity in captive and wild colonies of naked mole-rats, Heterocephalus glaber.

To investigate the endocrine cause of reproductive suppression in nonbreeding female naked mole-rats, animals from 35 colonies were studied in captivity. Urinary and plasma progesterone concentrations were elevated in pregnant females (urine: 10.0-148.4 ng/mg Cr, 27 samples from 8 females; plasma: 3.6-30.0 ng/ml, 5 samples from 5 females; Days 21-40 of pregnancy) and cyclic breeding females (urine: 0.5-97.8 ng/mg Cr, 146 samples from 7 females; plasma: less than 1.0-35.4 ng/ml, 25 samples from 7 females). The latter group showed cyclic patterns of urinary progesterone, indicating a mean ovarian cycle length of 34.4 +/- 1.6 days (mean +/- s.e.m.) with a follicular phase of 6.0 +/- 0.6 days and a luteal phase of 27.5 +/- 1.3 days (19 cycles from 9 breeding females). In non-breeding females urinary and plasma progesterone values were undetectable (urine: less than 0.5 ng/mg Cr, 232 samples from 64 females; plasma: less than 1.0 ng/ml, 7 samples from 6 females). Breeding females had higher (P less than 0.001) plasma LH concentrations (3.0 +/- 0.2 mi.u./ml, 73 samples from 24 females) than did non-breeding females (1.6 +/- 0.1 mi.u./ml, 57 samples from 44 females). Urinary and plasma progesterone concentrations in non-breeding females from wild colonies situated near Mtito Andei, Kenya, were either below the assay sensitivity limit (urine: less than 0.5 ng/mg Cr, 11 females from 2 colonies; plasma: less than 1.0 ng/ml, 25 females from 4 colonies), or very low (plasma: 1.6 +/- 0.6 ng/ml, 15 females from 4 colonies). In captivity, non-breeding females removed from their colonies (i.e. the dominant breeding female) and either paired directly with a non-breeding male (N = 2), or removed and housed singly for 6 weeks before pairing with a non-breeding male (N = 5) may develop a perforate vagina for the first time in as little as 7 days. Urinary progesterone concentrations rose above 2.0 ng/mg Cr (indicative of a luteal phase) for the first time 8.0 +/- 1.9 days after being separated. These results suggest that ovulation is suppressed in subordinate non-breeding female naked mole-rats in captive and wild colonies, and show that plasma LH concentrations are significantly lower in these non-breeding females. This reproductive block in non-breeding females is readily reversible if the social factors suppressing reproduction are removed.

Animals↗

PubMed1992

Modulation of luteinizing hormone and follicle-stimulating hormone in circulation by interactions between endogenous opioids and oestradiol during the peripubertal period of heifers.

The aim of this study was to determine whether the decline in oestradiol inhibition of circulating luteinizing hormone (LH) and follicle-stimulating hormone (FSH) during the peripubertal period of heifers is associated with a change in opioid modulation of LH and FSH secretion. Opioid inhibition of LH secretion was determined by response to administration of the opioid antagonist naloxone. Prepubertal heifers (403 days old) were left as intact controls, ovariectomized or ovariectomized and chronically administered oestradiol. Control heifers were used to determine time of puberty. Three weeks after ovariectomy, four doses of naloxone (0.13-0.75 mg kg-1 body weight) or saline were administered to heifers in the treatment groups in a latin square design (one dose per day). Blood samples were collected at intervals of 10 min for 2 h before and 2 h after administration of naloxone. This procedure was repeated four times at intervals of 3 weeks during the time intact control heifers were attaining puberty. All doses of naloxone induced a similar increase in concentration of serum LH within a bleeding period. During the initial bleeding period (before puberty in control heifers), administration of naloxone induced an increase in LH concentration, but the response was greater for heifers in the ovariectomized and oestradiol treated than in the ovariectomized group. At the end of the study when control heifers had attained puberty (high concentrations of progesterone indicated corpus luteum function), only heifers in the ovariectomized and oestradiol treated group responded to naloxone. Opioid inhibition of LH appeared to decline in heifers during the time control heifers were attaining puberty. Heifers in the ovariectomized group responded to naloxone at the time of administration with an increase in FSH, but FSH did not respond to naloxone at any other time. Administration of naloxone did not alter secretion of FSH in ovariectomized heifers. These results suggest that opioid neuropeptides and oestradiol are involved in regulating circulating concentrations of LH and possibly FSH during the peripubertal period. Opioid inhibition of gonadotrophin secretion appeared to decline during the peripubertal period but was still present in ovariectomized heifers treated with oestradiol after the time when age-matched control heifers had attained puberty. We conclude that opioid inhibition is important in regulating LH and FSH in circulation in heifers during the peripubertal period. However, opioids continue to be involved in regulation of circulating concentrations of LH after puberty.

Animals↗

PubMed1988

Regulation of LH subunit mRNA levels by gonadal hormones in female rats.

To determine the physiological role of the ovaries in regulation of LH subunit gene expression, levels of cytoplasmic mRNA were measured in a cDNA-RNA dot-blot hybridization assay. An increase (twofold) in alpha mRNA was first detected 8 days after ovariectomy and then remained stable for 4 weeks. In contrast, LH-beta mRNA increased by 60-79% within 12 h of removing the ovaries and then rose progressively to six times the intact values at 3 and 4 weeks. Increases in LH-beta mRNA were always greater than those of alpha mRNA. Oestradiol, and oestradiol plus progesterone, but not progesterone alone, prevented the rise in alpha and LH-beta mRNA 10 days after ovariectomy. Three days after ovariectomy, alpha mRNA, but not LH-beta mRNA, was suppressed to below intact control values by oestradiol and oestradiol plus progesterone, indicating greater sensitivity of alpha mRNA to oestradiol inhibition at this stage. A single injection of oestradiol (1 microgram s.c.) to rats ovariectomized 14 days previously transiently suppressed alpha and LH-beta mRNA levels and serum LH concentrations in parallel for 1-8 h, after which high preinjection values were restored. However, pituitary LH content remained suppressed after LH mRNA levels had returned to the control values of ovariectomized rats. In most instances there was a qualitative positive correlation between changes in alpha and LH-beta mRNA, pituitary LH content and serum LH concentrations. LH content reflected LH-beta mRNA changes more closely than those of alpha mRNA. However, in oestradiol-treated rats ovariectomized 10 days previously, LH content remained increased despite normalization of the LH-beta and alpha mRNA levels, suggesting differential sensitivity to oestradiol of the gene expression and translational processes. Thus divergence of pre- and post-translational regulation of LH biosynthesis was demonstrated. These results imply an important physiological role for female sex hormones in the control of LH gene expression and LH biosynthesis. Prolactin mRNA fell by 30-50% for the first 2 weeks after ovariectomy, but by 3 and 4 weeks values were similar to those of intact controls. Serum and pituitary prolactin levels were reduced by 50% or more at all time-points, despite normalization of mRNA. Treatment of ovariectomized rats for 10 days with oestradiol and progesterone, either alone or combined, reversed the fall in prolactin mRNA and serum and pituitary prolactin levels. These changes in prolactin gene expression and synthesis were opposite to those of LH subunits in response to the same in-vivo hormone manipulations.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1977

Steroids and pituitary responsiveness in female, androgenized female and male rats.

Spontaneous gonadotrophin release and the gonadotrophin response to LH releasing factor (RF) were studied in pro-oestrus, androgenized female and male rats. The animals were either intact or gonadectomized (about 32 h previously) and treated with various steroids. The gonadotrophin response (especially LH) was much lower in intact males and androgenized females than in pro-oestrous females. Oestrogen plus progesterone increased plasma gonadotrophin concentrations and responses in ovariectomized rats, but inhibited the increase in the plasma gonadotrophin concentration and the LH response which followed castration in males. As in the normal female, ovariectomy decreased the LH response but increased the plasma FSH concentration and response in the androgenized female; oestrogen and progesterone had relatively little effect. Apart from reducing the postcastration rise in plasma FSH, testosterone had no significant effect in gonadectomized male or female animals. These results show that the effect of steroids on the gonadotrophin response to LH-RF as well as the spontaneous secretion of gonadotrophin depends upon sexual differentiation of the hypothalamo-hypophysial system. Studies with various metabolites of progesterone indicated that the facilitatory action of this steroid could be due, in part, to a 5alpha-reduced derivative.

Animals↗

PubMed1991

Influence of growth rate and exposure to bulls on age at puberty in beef heifers.

Two experiments were conducted to test the following hypotheses: 1) exposure of beef heifers to sterile bulls increases the proportion of heifers attaining puberty by 14 mo of age and 2) rate of growth interacts with bull exposure to influence age at puberty in beef heifers. In Exp. I, heifers were assigned to one of two treatments: 1) heifers were exposed to bulls (BE; approximately 70-d period of exposure) or 2) heifers were isolated from bulls (NE) and served as controls. In Exp. II, heifers were assigned to either BE or NE treatments (175-d period of exposure to bulls) and were fed to gain at a moderate (MG; .6 kg/d) or high (HG; .8 kg/d) growth rate. Blood samples were collected twice weekly to determine concentrations of progesterone indicative of onset of corpus luteum function and puberty. In Exp. I a greater (P less than .05) proportion of heifers receiving the BE treatment than of heifers receiving the NE treatment initiated corpus luteum function by 14 mo of age. In Exp. II, there was a bull exposure x growth rate interaction (P less than .05). The effect of bull exposure was greater within the HG groups than within the MG groups. However, heifers fed to attain a moderate or high growth rate and exposed to bulls attained puberty at younger ages than heifers not exposed to bulls and fed to attain a moderate or high growth rate. Mean ages at puberty were 375, 422, 428, and 449 (pooled SEM = 8.6) d for heifers in the BE-HG, BE-MG, NE-HG, and NE-MG groups, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1975

Plasma levels of progesterone and oestrogens in women treated with an oral contraceptive of low oestrogen content (Ovostat 1375).

The plasma levels of progesterone and oestrogens were measured during treatment with an oral contraceptive containing 37.5 mug of ethinyl oestradiol and 1 mg of lynestrenol (= 3-desoxy-17alpha-ethinyl-19-nortestosterone) (Ovostat 1375, Organon, Oss, Holland). Blood samples were taken every day during 9 complete cycles in 5 healthy women. The plasma levels of progesterone were in the range of those found during the early follicular phase of the normal women. No ovulation seemed to have occurred. The mean plasma levels of oestrogens (oestradiol and oestrone) during treatment were below those found during early follicular phase of 34 normal cycles although overlapping of values occurred. The ratio between oestradiol and oestrone during treatment was 1:2 vs. 1:1 during the early follicular phase of the normal cycles. In two cycles treatment was started during the midcyclic rise of oestrogens. No rise of progesterone indicating corpus luteum formation was found. Despite the low amount of oestrogen in the drug the ovaries appeared to secrete minimal amounts of sex steroids. The lynestrenol content is likely to be partly responsible for the inhibition of ovulation and the additional suppression of steroidogenesis.

Adult↗

PubMed1987

Proliferative potential and polymorphism of human endometrial stromal cells.

The proliferative potential of stromal cells from human endometrium, separated from glands by dispersion in the presence of collagenase and subsequent passage through a sieve, was evaluated by determining the total number of cell doublings achieved when cells were repeatedly subcultured in a 1:2 split ratio in Ham's F-10 medium containing 10% fetal bovine serum (FBS). Fifty doublings or more (up to 100) were observed in 8 of the 26 specimens (30%) which we examined. This number of doublings is high for cells obtained from adult tissues and may in part reflect the unusually great proliferative capacity of human endometrium when compared to that of other tissues. The shape of the stromal cells depended on the medium in which they were originally cultured. Cells cultured in Ham's F-10 medium containing 10% FBS showed the typical fibroblastic morphology at confluence; they appeared elongated or spindle-shaped and formed monolayers. In contrast, cultures in CMRL-1066 medium in the presence of 10% FBS appeared polygonal or stellate-shaped and also formed monolayers. In about 50% of the cultures in CMRL-1066 medium we observed fibroblast-shaped cells that superficially resembled cells grown in Ham's F-10 medium, but were able to form dome structures. In some cultures the regions of prominent overgrowth were macroscopically visible. Switching media during later passages did not reverse the shape of the cells obtained in CMRL-1066 medium or that of the fibroblast-shaped cells in Ham's F-10 medium, suggesting either that the growth of a subpopulation was favoured early during cellular adaptation to primary culture or that there was a single cell population whose phenotype was determined early in culture and then no longer responded to medium factors. Examination of the cytoskeleton after visualization with rhodamine-labelled phalloidin revealed that the arrangement of the microfilaments corresponded to the cell shape observed in living cells under the phase contrast microscope. Distinct changes in morphology were observed when primary stromal cell cultures in CMRL-1066 medium were exposed to progesterone, indicating that progestins may affect cytoskeletal proteins.

Actin Cytoskeleton↗

PubMed1982

Conversion of progesterone from the adrenal or ovary to deoxycorticosterone in plasma.

The in vivo conversion of progesterone to deoxycorticosterone (DOC) by peripheral 21 hydroxylation was studied in normal men and women. The technique used was to infuse labeled progesterone under steady state conditions and isolate the precursor and product from blood by multiple chromatography steps. DOC was chromatographed as both the steroid and its acetylated derivative. The conversion rate was found to be 1.3 +/- 0.1% in men and women despite differences in the concentration of progesterone during the cycle. Since progesterone was very low in men and women in the follicular phase of the cycle, we conclude that DOC is derived from direct secretion. However, progesterone rises to 1073 +/- 101 ng per dl in the luteal phase and the calculations indicate that DOC increases from 8.3 +/- 0.4 (SE) to 15.6 +/- 1.3 ng per dl. 3/4 of luteal phase DOC is from conversion of progesterone. Acute ACTH increases both progesterone and DOC, and almost all of the DOC in plasma is from direct secretion. However, chronic ACTH excess and adrenal 21 hydroxylase deficiency is associated with a fraction (1/4-1/5) of DOC from progesterone indicating that the peripheral conversion rate is unrelated to the adrenal enzyme defect.

Adrenal Glands↗

PubMed1978

Milk progesterone to predict reproductive status in a commercial dairy herd.

Progesterone was measured in milk strippings of cows to evaluate potential diagnosis of pregnancy and to estimate embryonic mortality. Progesterone in milk was measured at 20 days and at 10-day intervals thereafter through 90 days after artificial insemination when the cows were palpated for pregnancy. Mean progesterone for 24 nonpregnant cows in estrus was 4.5 ng/ml at 20 days after insemination. Cows were classified as pregnant or nonpregnant by a formula which provided a progesterone concentration for which the probability of nonpregnancy was .8. At 20 days after insemination, the success in identifying the nonpregnant and pregnant cows was 87% and 67%. Ten of 34 nonpregnant cows with low (nonpregnant range) progesterone in milk on day 20 were not seen in estrus. Progesterone at sampling intervals after 20 days was used to investigate incorrect assessments. Seventeen nonpregnant cows had progesterone indicative of pregnancy at day 20. Progesterone in milk decreased at various later sampling intervals in all 17 cows. Two of these cows were diagnosed as having pathology of their reproductive tracts. If the other 15 cows experienced death of their embryos, the frequency of embryonic mortality was 28%.

Animals↗

PubMed1989

Effect of treatment with progesterone on pregnancy rate and plasma concentrations of progesterone in Holstein cows.

Progesterone-releasing intravaginal devices inserted into the vaginas of dairy cows between d 5 to 12 (n = 28) or d 10 to 17 (n = 27) after insemination increased pregnancy rate to 60 over 30% in untreated control cows (n = 30). Plasma progesterone concentrations were increased during both progesterone treatments. Subtraction of the estimated contribution of exogenous progesterone indicated that endogenous, luteal progesterone was reduced during d 10 to 17 but not during d 5 to 12. Supplemental progesterone increased pregnancy rate but suppressed endogenous production of progesterone when administered during d 10 to 17 after insemination.

Administration, Intravaginal↗