SURVIVAL AND GONADOTROPHIN RESPONSIVENESS OF LUTEAL CELLS IN VITRO

1971 ◽  
Vol 68 (1_Suppl) ◽  
pp. S295-S317 ◽  
Author(s):  
William Hansel

ABSTRACT Simplified methods for incubating luteal tissues have been developed. Progesterone biosynthesis in washed, minced bovine luteal tissue is stimulated by added bovine LH. The response is linear in the range 2–200 ng added LH per ml of medium. The use of covariance analysis to correct for differences in time elapsing between mincing the tissue and the beginning of incubation reduces the standard error of the mean and results in marked improvement in the indices of precision. Progesterone biosynthesis in washed, minced bovine luteal tissues appears specific for LH; no other pituitary hormones give a response, and the response is completely negated by adding anti-bovine LH serum to the incubation medium. Prior treatment of cattle from which the incubated corpora lutea are obtained with various levels of human chorionic gonadotrophin, results in greatly increased luteal tissue weights. However, this tissue has a markedly reduced sensitivity to LH added in vitro. No conclusive evidence was found for a feedback inhibition of progesterone on its own synthesis in this system. The incubation system developed is sensitive enough to serve as a bioassay for LH in biological tissues and fluids. Preliminary data suggest that a simplified protein binding assay can be successfully used to measure the progestins synthesized by minced, washed bovine luteal tissue in response to added bovine LH.

Reproduction ◽  
2017 ◽  
Vol 153 (2) ◽  
pp. 233-240 ◽  
Author(s):  
Kenneth P McNatty ◽  
Derek A Heath ◽  
Zaramasina Clark ◽  
Karen Reader ◽  
Jennifer L Juengel ◽  
...  

Ewes heterozygous for combinations of the Inverdale (FecXI; I+), Booroola (FecB; B+) and Woodlands (FecX2W; W+) mutations have ovulation rates higher than each mutation separately. The aims of the experiments described herein were to examine the ovarian phenotypes in I+B+ and I+B+W+ ewes and to compare these with the appropriate ++ (controls), I+ and BB animals available for this study. The mean ± s.e.m. ovulation rates in the ++ (n = 23), I+ (10), I+B+ (7), I+B+W+ (10) and BB (3) animals were 1.8 ± 0.1, 2.5 ± 0.2, 6.6 ± 1.0, 9.6 ± 0.9 and 9.7 ± 0.9 respectively. The maximum number of granulosa cells per follicle in the ++ and I+ genotypes was accumulated after exceeding 5 mm diameter, whereas in I+B+, I+B+W+ and BB animals, this was achieved when follicles reached >2–3 mm. The number of putative preovulatory follicles, as assessed from those with LH-responsive granulosa cells, 24 h after the induction of luteolysis, was higher (P < 0.01) in the I+B+ and I+B+W+ compared to the ++ and I+ genotypes. The median follicular diameters of these follicles in the ++, I+, I+B+, I+B+W+ and BB genotypes were 6, 5, 3, 3 and 3 mm respectively. The total number of granulosa cells in the putative preovulatory follicles when added together, and total mass of luteal tissue, did not differ between the genotypes. Thus, despite large ovulation rate differences between animals with one or more fecundity genes, the total cell compositions over all preovulatory follicles and corpora lutea, when added together, are similar to that from the one or two such follicles in the wild types.


1989 ◽  
Vol 121 (3) ◽  
pp. 459-465 ◽  
Author(s):  
M. G. Hunter ◽  
J. A. Southee

ABSTRACT In order to investigate the development and possible heterogeneity in the luteal population following superovulation, anoestrous ewes were induced to ovulate using progestagen priming followed by injections of pregnant mare serum gonadotrophin (1000 IU) and hCG (1000 IU). Ovaries were recovered from ewes on each of days 2, 4, 6, 8, 10, 12 and 15, and the weight, progesterone content, 125I-labelled hCG binding and progesterone synthesis in vitro of the individual corpora lutea measured. The results obtained showed that plasma progesterone concentrations on the day of slaughter were significantly correlated with time (P<0·05), total weight of luteal tissue (P< 0·001) and number of corpora lutea (P<0·05). The number of corpora lutea recovered per animal ranged from two to 12 and was significantly (P<0·05) correlated with the day after hCG injection until day 10. There was much variation between individual corpora lutea, particularly in terms of weight and progesterone content, although both were significantly (P<0·001) correlated with day of recovery until day 10. 125I-Labelled hCG binding was significantly (P<0·001) correlated with time until day 15. There was a significant (P<0·001) effect of age of the tissue on progesterone production in vitro, with output declining throughout the luteal phase. These results show that the number of corpora lutea induced by superovulation in anoestrous ewes was very variable, and suggest that ovulation may have continued to occur during the luteal phase. Moreover, there was much variation between individual corpora lutea recovered from the same animal, and thus it should not be assumed that an individual corpus luteum is representative of the entire population. Journal of Endocrinology (1989) 121, 459–465


1984 ◽  
Vol 103 (1) ◽  
pp. 107-110 ◽  
Author(s):  
M. G. Hunter

ABSTRACT Human luteal tissue recovered from varying stages of the luteal phase was minced and incubated for 3 h and the effect of human chorionic gonadotrophin (hCG), prolactin and hCG + prolactin on progesterone and oestradiol production measured. While hCG generally enhanced both progesterone and oestradiol synthesis, prolactin alone at either 20 or 200 μg/l had no significant effect on steroidogenesis. When prolactin was added along with hCG in four of six corpora lutea, however, progesterone production significantly increased and in three of six corpora lutea oestradiol production was increased above that induced by hCG alone. It is concluded that prolactin may play some role in the control of steroidogenesis by the human corpus luteum. J. Endocr. (1984) 103, 107–110


1973 ◽  
Vol 21 (3) ◽  
pp. 321 ◽  
Author(s):  
MJ Smith ◽  
RA How

Reproduction was studied in eight female T. caninus held in captivity in Armidale, N.S.W., for up to 5 yr. Oestrus was diagnosed from the vast increase in epithelial cells in the vaginal smear, post-oestrus being detected by the appearance of many leucocytes and of some elongate epithelial cells. The mean of 17 oestrous cycles was 26.4+- 1.0 days and the mean of 10 gestation periods was 16.2+-0.2 days. The teats evert and the female first ovulates at the end of her 2nd year, but no captive female gave birth till near the end of her 3rd year. In the anatomy of the uteri and vaginae, T. caninus resembles T. vulpecula but the ovaries of T. caninus are markedly distinguished by the presence of up to seven large corpora lutea. Although the weight of the luteal tissue may contribute as much as 83.9 % of the total ovarian weight, there is no evidence from the uteri that these large corpora lutea are functional in hormone secretion. The luteal cells are large but vacuolated and are separated by a well developed network of connective tissue. As the corpora lutea persist throughout the life of the animal, it is suggested that their number be used to indicate the maximum age of the animal.


1990 ◽  
Vol 126 (2) ◽  
pp. 297-307 ◽  
Author(s):  
H. M. Picton ◽  
C. G. Tsonis ◽  
A. S. McNeilly

ABSTRACT The study investigated the relationship between the plasma concentration of FSH and the stimulation of preovulatory follicle growth in vivo in ewes chronically treated with the gonadotrophin-releasing hormone (GnRH) agonist buserelin (HOE 766). Welsh Mountain ewes with regular oestrous cycles were treated for 6 weeks with two discs implants placed s.c., each containing 5 mg of the agonist in a matrix of polyhydroxybutyric acid. Treatment with the agonist for 35 days produced a sustained suppression of the plasma concentration of FSH, stopped the pulsatile release of LH and prevented follicular development beyond 2·5 mm diameter. There was no difference between the total number of follicles > 1·0 mm diameter present in the ovaries of GnRH agonist-treated ewes and day 8 luteal phase control ewes. During the sixth week of agonist treatment ewes were infused with ovine FSH (6 μg NIADDK-oFSH16/h) in the presence of only basal concentrations of LH. After 24, 48, 72 or 120 h of FSH infusion, the mean number of follicles > 1 ·0 mm diameter per ewe was not significantly different between treated and control animals. Infusion of FSH caused a timedependent increase in (1) the number of follicles per ovary >2·5 mm, (2) the mean diameter of these follicles and (3) the proportion of the large follicles which could be classified as oestrogenic (> 3·7 nmol oestradiol/follicle per h in vitro). Injection of human chorionic gonadotrophin (750IU i.m.) after 120 h of FSH infusion caused the majority of these large follicles to ovulate and form apparently normal corpora lutea. These results indicate that, in the absence of pulsatile LH, FSH stimulates the growth of normal large oestrogenic follicles which, when stimulated, ovulate to produce viable corpora lutea. Journal of Endocrinology (1990) 126, 297–307


1997 ◽  
Vol 154 (2) ◽  
pp. 259-265 ◽  
Author(s):  
R K Arioua ◽  
A Benhaïm ◽  
C Féral ◽  
P Leymarie

Abstract Previous studies on rabbit corpus luteum (CL) led to the conclusion that the luteotrophic complex, in rabbit, may include LH as well as oestradiol for normal luteal function. However, the requirement for LH is controversial. We have recently demonstrated the existence of a human chorionic gonadotrophin (hCG)-stimulated aromatase activity in cultured corpora lutea from a hyperstimulated pseudopregnant rabbit model, which develops a large number of corpora lutea, with only a few or no follicles in the ovaries. The present study was undertaken to investigate the in vitro responsiveness to hCG, dibutyryl cAMP (dbcAMP) and oestradiol of those corpora lutea. Pseudopregnancy (PP) was induced in rabbits by i.m. injection of 200 IU equine chorionic gonadotrophin daily for 2 days followed on day 4 by i.m. injection of 200 IU hCG (day 0 of PP). Luteal tissue and small and large luteal cells obtained at days 5 and 9 of PP were cultured for 24 h or during several days respectively with or without hCG, dbcAMP or oestradiol. Basal progesterone secretion was 3·6- and 22-fold higher in large cells compared with small ones at day 5 and 9 of PP respectively. When stimulated by small doses of hCG, luteal tissue responded by a 5-fold increase in progesterone secretion. Small cells produced four times higher amounts of progesterone than controls in the presence of 1 mIU/ml hCG and more than ten times in the presence of 0·1 IU/ml hCG, whereas large cells were insensitive to hCG stimulation. dbcAMP mimicked the effect of hCG on progesterone secretion by luteal tissue and luteal cells and oestradiol stimulated basal progesterone secretion in both small and large luteal cells. Given the large contribution of non stimulated large cells to luteal progesterone production and the remarkably high sensitivity of luteal tissue to gonadotrophin in vitro it seems that interactions between the two types of cells might occur during LH stimulation. Our results suggest that LH could participate in the luteotrophic complex at least in part through the stimulation of endogenous oestradiol production by luteal cells. Journal of Endocrinology (1997) 154, 259–265


1988 ◽  
Vol 117 (2) ◽  
pp. 167-172 ◽  
Author(s):  
S. Atkinson

ABSTRACT Sixteen ewes in mid-seasonal anoestrus were stimulated to ovulate using sequential injections of FSH (total dose 10 mg) over a 4-day period. Half of the ewes received a dietary growth promotant (monensin) known to enhance the ovarian response to exogenous gonadotrophins. The ewes were ovariectomized on day 5 or 11 (day 0 = the initiation of FSH treatment). Serial blood samples were taken in half of the ewes to determine peripheral concentrations of LH and a single sample of ovarian venous blood was collected before ovariectomy. All luteal structures were dissected from the ovaries, counted and incubated in vitro to determine progesterone production. The luteal structures were then examined histologically for the abundance of luteal cells. The physical appearance of the ovary, along with plasma concentrations of LH and ovarian venous oestradiol indicated that the monensin-treated ewes ovulated before control ewes. The corpora lutea from control ewes produced significantly (P <0·05) more progesterone than did the corpora lutea from the monensin-treated group. Furthermore, only 7% of the remaining luteal structures in the monensin-treated group produced significant amounts of progesterone on day 11, whereas 61% of the luteal structures in the control group were actively secreting progesterone. The mean number of granulosa cells in the follicles was similar at ovulation in the two groups, but the mean numbers of large and small luteal cells were significantly (P <0·05) lower in luteal structures from the monensin-treated ewes than in those from the control ewes. It is therefore postulated that inadequate corpora lutea function following precocious ovulation is due to a lack of luteal cell development formed after premature luteinization. J. Endocr. (1988) 117, 167–172


Steroids ◽  
1970 ◽  
Vol 15 (6) ◽  
pp. 789-797 ◽  
Author(s):  
Masao Maeyama ◽  
Hirozo Matuoka ◽  
Yoko Tuchida

1995 ◽  
Vol 61 (1) ◽  
pp. 57-62 ◽  
Author(s):  
J. A. Abecia ◽  
S. M. Rhind ◽  
T. A. Bramley ◽  
S. R. McMillen

AbstractTwo groups of eives were fed to provide 1·5 × (high, H; no. = 13) or 0·5 × (low, L; no. = 12) energy requirements for maintenance of live weight from 12 days before a synchronized mating in November until slaughter at 14 days after mating and the effects on embryo survival and associated patterns of gonadotropin secretion, and ovarian follicle and corpus luteum function were investigated. Proportionately, there were more pregnant ewes in the H group than the L group (0·62 v. 0·08; %2 = 7·67; P < 0·01) at day 14 of pregnancy but there were no differences in mean LH concentrations, LH pulse frequencies or amplitudes, either before mating and ovulation (follicular phase) or at day 10 after mating (luteal phase). The mean size (mm) of the three largest follicles (H: 5·69; L: 5·65; s.e.d. = 0·21), the proportion of these follicles that were oestrogenic (secreting > 500 pg oestradiol per h; H: 0·29; L: 0·28; y) = 0·01; P > 0·05) and secretion (pg/h) in vitro of oestradiol (H, 294; L, 386; s.e.d. = 146) (pg/h) and testosterone (H: 636; L: 508; s.e.d. = 293) by these follicles were similar for both treatments. There were no treatment differences in LH receptor concentrations (pg hormone bound per mg protein) in granulosa (H: 69·02; L: 67·76; s.e.d. = 0·20) and thecal (H: 46-88; L: 50·82; s.e.d. = 0·19) tissues. However, there was a higher concentration of receptors in the thecal tissue of oestrogenic follicles ofL than H ewes (167 v. 62; s.e.d. = 18; P < 0·05). Mean weights (g) of corpora lutea (H: 0·72; L: 0·59; s.e.d. = 0·003; P = 0·09), progesterone secretion (ng/mg per h) in vitro by luteal tissue (H: 1·75; L: 1·78; s.e.d. = 0·30) and LH receptor concentrations in corpora lutea (H: 58·16; L: 54·27; s.e.d. = 25·14) were similar for both treatments. It is concluded that the reduction in embryo survival associated with a reduced level of food intake was not attributable to a reduction in LH secretion, inadequacies in follicle growth and development or in the capacity of the corpora lutea to synthesize and release progesterone.


Reproduction ◽  
2007 ◽  
Vol 133 (1) ◽  
pp. 187-196 ◽  
Author(s):  
Nicole Tinfo ◽  
Carolyn Komar

Peroxisome proliferator-activated receptor γ (PPARγ) has been shown to stimulate progesterone production by bovine luteal cells. We previously reported higher expression of PPARγ in old compared with new luteal tissue in the rat. The following studies were conducted to determine the role of PPARγ in rat corpora lutea (CL) and test the hypothesis that PPARγ plays a role in the metabolism of progesterone and/or luteal lifespan. Ovaries were removed from naturally cycling rats throughout the estrous cycle, and pseudopregnant rats. mRNA for PPARγ and P450 side-chain cleavage (SCC) was localized in luteal tissue byin situhybridization, and protein corresponding to PPARγ and macrophages identified by immunohistochemistry. Luteal tissue was cultured with agonists (ciglitazone, prostaglandin J2) or an antagonist (GW-9662) of PPARγ. Progesterone was measured in media by RIA and levels of mRNA for 20α-hydroxysteriod dehydrogenase (HSD) and bcl-2 were measured in luteal tissue after culture by RT-PCR. An inverse relationship existed between the expression of mRNA for SCC and PPARγ. There was no effect of PPARγ agonists or the antagonist on luteal progesterone productionin vitro, or levels of mRNA for 20α-HSD. PPARγ protein was localized to the nuclei of luteal cells and did not correspond with the presence of macrophages. In new CL, ciglitazone decreased mRNA for bcl-2 on proestrus, estrus, and metestrus. Interestingly, GW-9662 also decreased mRNA for bcl-2 on proestrus and diestrus in old and new CL, and on metestrus in new CL. These data indicate that PPARγ is not a major player in luteal progesterone production or metabolism but may be involved in regulating luteal lifespan.


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