IN-VITRO STEROIDOGENESIS OF NEWLY FORMED CORPORA LUTEA AND THE NON-LUTEAL OVARY IN THE RAT, RABBIT, HAMSTER AND GUINEA-PIG

1980 ◽  
Vol 84 (1) ◽  
pp. 101-108 ◽  
Author(s):  
P. F. TERRANOVA ◽  
S. K. SAIDAPUR ◽  
G. S. GREENWALD

The steroidogenic abilities of the newly formed corpus luteum (8–10 h after ovulation) and the non-luteal ovary were compared in the guinea-pig, hamster, rabbit and rat using an invitro incubation technique. Histologically, newly formed rat corpora lutea (CL) were highly luteinized whereas the CL of the rabbit and guinea-pig were only partially luteinized. The CL of the hamster showed the least amount of luteinization. Serum progesterone was highest in the rat (18 ± 3 (s.e.m.) ng/ml). In the hamster, it was about 8 ng/ml, whereas in the rabbit and guinea-pig it was about 1 ng/ml. Serum androstenedione ranged between 0·5 and 1 ng/ml. Serum testosterone was lowest in the hamster (60 pg/ml) and highest in the rabbit (470 pg/ml), whereas in the rat and guinea-pig, testosterone levels were similar (about 240 pg/ml). Serum oestrogens were at baseline levels in all species. The CL of the rat exhibited considerably greater steroidogenic ability than the CL of the other species, producing 70 ± 6 ng progesterone/mg per h, 215 ± 14 pg androstenedione/mg per h, 49 ± 3 pg testosterone/mg per h, 3 pg oestrone/mg per h and 1 pg oestradiol/mg per h. Rabbit CL produced only progesterone (7 ± 2 ng/mg per h). Newly formed hamster CL produced none of the above steroids. In general, the ability of the CL to produce progesterone in vitro correlated with the degree of luteinization found by histological observation. Guinea-pig CL were embedded deeply in the ovary and could not be obtained without damage. Consequently, a portion of the ovary containing a corpus luteum was incubated. There was no difference in the steroid production by this portion of the ovary compared with the non-luteal ovary. The non-luteal ovary of the rat produced the highest amount of progesterone (10 ± 2 ng/mg per h). The guinea-pig non-luteal ovary produced about 5 ± 2 ng progesterone/mg per h, whereas the non-luteal ovary of the rabbit did not produce any. On the other hand, the hamster non-luteal ovary lost progesterone. Non-luteal ovaries from all species produced androgens. The non-luteal ovary of the guinea-pig contained especially large numbers of atretic antral follicles. The guinea-pig non-luteal ovary produced extremely large amounts of androstenedione (1110 ± 210 pg/mg per h) and testosterone (606 ± 154 pg/mg per h) compared with the amounts produced by the non-luteal ovary of the rat, hamster and rabbit. In the non-luteal ovary, interstitium and atretic antral follicles are the probable source of androgens. Oestrogen production by the non-luteal ovary was at baseline levels in the four species studied correlating with the absence of healthy antral follicles. The results indicate the extreme species differences that exist in ovarian function in the early postovulatory period.

1991 ◽  
Vol 19 (01) ◽  
pp. 61-64 ◽  
Author(s):  
Satoshi Usuki

The effect of herbal components of Tokishakuyakusan on somatomedin C/insulin-like growth factor I (IGF-1) level in medium from rat corpora lutea incubated in vitro was examined. Hoelen + peony root + Japanese angelica root, hoelen + peony root, hoelen + Japanese angelica root or peony root + Japanese angelica root decreased the IGF-1 level. The data suggest that constituent herbal components of Tokishakuyakusan regulate the IGF-1 level by rat corpora lutea.


Reproduction ◽  
2014 ◽  
Vol 147 (2) ◽  
pp. 189-197 ◽  
Author(s):  
Noriyuki Takahashi ◽  
Wataru Tarumi ◽  
Bunpei Ishizuka

Most of the previous studies on ovarian hyaluronan (HA) have focused on mature antral follicles or corpora lutea, but scarcely on small preantral follicles. Moreover, the origin of follicular HA is unknown. To clarify the localization of HA and its synthases in small growing follicles, involvement of HA in follicle growth, and gonadotropin regulation of HA synthase (Has) gene expression, in this study, perinatal, immature, and adult ovaries of Wistar-Imamichi rats were examined histologically and biochemically and byin vitrofollicle culture. HA was detected in the extracellular matrix of granulosa and theca cell layers of primary follicles and more advanced follicles. Ovarian HA accumulation ontogenetically started in the sex cords of perinatal rats, and its primary site shifted to the intrafollicular region of primary follicles within 5 days of birth. TheHas1–3mRNAs were expressed in the ovaries of perinatal, prepubertal, and adult rats, and the expression levels ofHas1andHas2genes were modulated during the estrous cycle in adult rats and following administration of exogenous gonadotropins in immature acyclic rats. TheHas1andHas2mRNAs were predominantly localized in the theca and granulosa cell layers of growing follicles respectively. Treatments with chemicals known to reduce ovarian HA synthesis induced follicular atresia. More directly, the addition ofStreptomyceshyaluronidase, which specifically degrades HA, induced the arrest of follicle growth in anin vitroculture system. These results indicate that gonadotropin-regulated HA synthesis is involved in normal follicle growth.


Development ◽  
1980 ◽  
Vol 60 (1) ◽  
pp. 405-418
Author(s):  
E. B. Ilgren

The growth of mouse trophectoderm depends upon the presence of the inner cell mass. Whether this applies to other species of mammals is not known. To investigate this problem, the guinea pig was selected for two reasons. Firstly, the growth of guinea-pig trophoblast resembles that of man. Secondly, earlier studies suggest that the proliferation of guinea-pig trophectoderm may not be under ICM control. Therefore, in the present study, the guinea-pig blastocyst was cut microsurgically to yield two tissue fragments. These contained roughly equal numbers of trophectodermal cells, one fragment being composed only of trophectoderm and the other containing ICM tissue as well. Subsequently, the growth of these mural and polar fragments was followed in vitro since numerous technical difficulties make an in vivo analysis of this problem impracticable. In a manner similar to the mouse, the isolated mural trophectoderm of the guinea pig stopped dividing and became giant. In contrast, guinea-pig polar fragments formed egg-cylinder-like structures. The latter contained regions structurally similar to two presumptive polar trophectodermal derivatives namely the ectoplacental and extraembryonic ectodermal tissues. These findings suggest that guinea-pig trophectodermal growth may occur in a manner similar to the mouse and thus be under ICM control.


1972 ◽  
Vol 55 (3) ◽  
pp. 599-607 ◽  
Author(s):  
B. T. DONOVAN ◽  
A. N. LOCKHART

SUMMARY The release of ovulating hormone after acute treatment with gonadal steroids, or corpus luteum removal on different days of the oestrous cycle, was studied in the guinea-pig. Injection of 25, 50 or 100 μg oestradiol or 2·5 mg progesterone on day 13 of the cycle had no effect upon gonadotrophin secretion as judged by follicular histology, but markedly altered the sizes of the corpora lutea of the previous ovulation. Treatment with oestradiol on day 14 did not elicit gonadotrophin secretion. However, administration of the same hormones to animals given 10 μg oestradiol benzoate 24 h earlier caused ovulation or follicular luteinization. Progesterone (2·5 mg) appeared least effective in stimulating gonadotrophin release; 25 μg oestradiol were more effective when given at 12.00 h than at 24.00 h but treatment with both hormones caused ovulation when given at either time of day. Luteal volumes were not affected. Removal of corpora lutea during the second half of the cycle advanced the time of expected ovulation to day 15 or earlier when the procedure was carried out on days 8 or 9, but not on days 10–13. It is concluded that 4–5 days must elapse between the fall in plasma progesterone level associated with corpus luteum regression and the release of ovulating hormone.


1983 ◽  
Vol 99 (2) ◽  
pp. 199-209 ◽  
Author(s):  
Valerie Urwin

Heterologous double-antibody radioimmunoassays were developed for the measurement of FSH and LH concentrations in the serum of both horses and donkeys. The FSH assay employed a rabbit anti-ovine FSH serum which showed a complete lack of cross-reaction with equine chorionic gonadotrophin (eCG) and negligible cross-reaction with equine LH. The LH assay utilized an antiserum raised against highly purified eCG. This similarly showed negligible cross-reaction with equine FSH but its high cross-reactivity with eCG prevented the measurement of equine LH concentrations in serum when eCG was also present. In both assays serial dilutions of horse and donkey serum were parallel to the standard. The assays were used to monitor changes in serum concentrations of FSH and LH during the first 100 days of pregnancy in pony mares and jenny donkeys. In both species during pregnancy LH levels reached a peak 1–2 days after ovulation. They then decreased rapidly to baseline levels where they remained until days 35–40 when the commencement of eCG production prevented their further measurement. Serum FSH concentrations, on the other hand, continued to fluctuate markedly throughout the first 100 days of pregnancy in both the ponies and donkeys. Pronounced surges in FSH levels occurred at regular intervals in some animals but the pattern of release was quite irregular in the others. The results of this study support the concept that it is continued pituitary FSH release, not eCG secretion, which is responsible for stimulating the secondary follicles which develop during early equine pregnancy. However, it appears likely that it is the LH-like activity of eCG which causes the subsequent ovulation and/or luteinization of these secondary follicles to produce accessory corpora lutea.


1997 ◽  
Vol 152 (1) ◽  
pp. 11-17 ◽  
Author(s):  
L-J Wang ◽  
M Brännström ◽  
K-H Cui ◽  
A P Simula ◽  
R P Hart ◽  
...  

Abstract Interleukin-1 (IL-1) is a multifunctional cytokine with profound effects on ovarian function. The effects of IL-1 on ovarian steroidogenesis have been demonstrated in several species. IL-1 mRNA levels are increased in the thecal layer of the ovulating follicle and IL-1β has been shown to induce ovulations in vitro. In this study we have investigated the presence and distribution of the mRNAs for type I IL-1 receptor (IL-1RtI) and for the naturally occurring IL-1 receptor antagonist (IL-1ra) in ovaries of adult cycling rats, to elucidate the target cells for IL-1 action. We have demonstrated the presence of mRNA for both substances by in situ hybridisation and reverse transcription PCR. mRNA for IL-1RtI was not found in primordial follicles but was abundant in the granulosa and thecal layer in developing follicles with stronger signals in the granulosa layer. In the preovulatory and ovulatory follicles, there was a further increase in the signal for IL-1RtI mRNA in the thecal layer compared with the granulosa layer. Corpora lutea were weakly positive at all stages and atretic follicles were largely negative. No mRNA was detected in oocytes of any stage. mRNA for IL-1ra showed a similar distribution to that of IL-1RtI. The changes in distribution suggest an action of IL-1 on rat granulosa cells during follicular development and on thecal cells during ovulation. Journal of Endocrinology (1997) 152, 11–17


2009 ◽  
Vol 297 (3) ◽  
pp. E676-E684 ◽  
Author(s):  
Anne Bachelot ◽  
Julie Beaufaron ◽  
Nathalie Servel ◽  
Cécile Kedzia ◽  
Philippe Monget ◽  
...  

The corpus luteum (CL) plays a central role in the maintenance of pregnancy in rodents, mainly by secreting progesterone. Female mice lacking prolactin (PRL) receptor (R) are sterile due to a failure of embryo implantation, which is a consequence of decreased luteinizing hormone (LH) receptor expression in the CL and inadequate levels of progesterone. We attempted to treat PRLR−/− females with human chorionic gonadotropin (hCG) and showed a de novo expression of LHR mRNA in the corpora lutea. Binding analysis confirmed that the LHR in hCG-treated PRLR−/− animals was functional. This was accompanied with increased expression of steroidogenic enzymes involved in progesterone synthesis. Despite these effects, no embryo implantation was observed because of high expression of 20α-hydroxysteroid dehydrogenase. To better appreciate the molecular mechanisms underlying maintenance of the CL, a series of mRNA expression-profiling experiments was performed on isolated corpora lutea of PRLR−/− and hCG-treated PRLR−/− mice. This approach revealed several novel candidate genes with potentially pivotal roles in ovarian function, among them, p27, VE-cadherin, Pten, and sFRP-4, a member of the Wnt/frizzled family. This study showed the differential role of PRL and LH in CL function and identified new targets of these hormones in luteal cells.


During the luteal phase of the cycle in many mammals, notably in the rabbit, ferret, and dog, the uterus undergoes changes which are designed to facilitate the implantation of the fertilised ovum. In other animals, such as the guinea-pig(5), the uterine changes during the luteal phase are histologically less obvious, but physiologically the uterine mucosa is in a peculiar condition of irritability. Injury to the mucosa at this time results in the production of large blocks of decidua-like tissue, to which the terms placentomata or deciduomata have been given. It has been shown by Marshall, Hammond, Loeb and others that the presence of the corpus luteum is essential for these post-ovulative uterine changes, and therefore that the corpus luteum is directly or indirectly responsible for their production. In the rabbit decidual tissue can only be induced to develop when functional corpora lutea are present in the ovary. In the guniea-pig (Loeb, 5) placentomata can be produced during the post-ovulation phase of the cycle in the unmated female, but in the rat Long and Evans (6) were unable to obtain a similar result. This discrepancy is undoubtedly due to the fact that in the short diœstrous cycle of the rat the corpora lutea undergo comparatively little development, whereas in the guinea-pig the cycle is longer and the corpora luteá are known to become active. During the pseudo-pregnancy which follows sterile copulation in the rat (Long and Evans, 6) and also during lactation (Corner and Warren, 2) placentomata can be produced. During both of these times corpora lutea develop to a greater extent than during the diœstrous cycle and become functional.


1974 ◽  
Vol 138 (3) ◽  
pp. 445-451 ◽  
Author(s):  
Abdulla A.-B. Badawy ◽  
Myrddin Evans

1. When assayed in fresh homogenates, guinea-pig liver tryptophan pyrrolase exists only as holoenzyme. It does not respond to agents that activate or inhibit the rat liver enzyme in vitro. Only by aging (for 30min at 5°C) does the guinea-pig enzyme develop a requirement for ascorbate. 2. The guinea-pig liver enzyme is activated by the administration of tryptophan but not cortisol, salicylate, ethanol or 5-aminolaevulinate. 3. The tryptophan enhancement of the guinea-pig liver pyrrolase activity is prevented by 0, 34 and 86% by pretreatment with actinomycin D, cycloheximide or allopurinol respectively. 4. The guinea-pig liver tryptophan pyrrolase is more sensitive to tryptophan administration than is the rat enzyme. On the other hand, the concentrations of tryptophan in sera and livers of guinea pigs are 45–52% less than those in rats. 5. It is suggested that tryptophan may regulate the activity of guinea-pig liver tryptophan pyrrolase by mobilizing a latent form of the enzyme whose primary function is the detoxication of its substrate.


2014 ◽  
Vol 26 (4) ◽  
pp. 493 ◽  
Author(s):  
B. Trigal ◽  
C. Díez ◽  
M. Muñoz ◽  
J. N. Caamaño ◽  
F. Goyache ◽  
...  

Asymmetry in the cow affects ovarian function and pregnancy. In this work we studied ovarian and uterine asymmetry. Synchronised animals, in which in vitro-produced embryos (n = 30–60) had been transferred on Day 5 to the uterine horn ipsilateral to the corpus luteum (CL), were flushed on Day 8. Ovulatory follicle diameter, oestrus response and total protein flushed did not differ between sides. However, a corpus luteum in the right ovary led to plasma progesterone concentrations that were higher than when it was present in the left ovary. Fewer embryos were recovered from the left than the right horn. Among 60 uterine proteins identified by difference gel electrophoresis, relative abundance of nine (acyl-CoA dehydrogenase, very long chain; twinfilin, actin-binding protein, homologue 1; enolase 1; pyruvate kinase isozymes M1/M2 (rabbit); complement factor B Bb fragment ; albumin; fibrinogen gamma-B chain; and ezrin differed (P < 0.05) between horns. Glucose concentration was higher, and fructose concentration lower, in the left horn. In a subsequent field trial, pregnancy rates after embryo transfer did not differ between horns (51.0 ± 3.6, right vs 53.2 ± 4.7, left). However, Day 7 blood progesterone concentrations differed (P = 0.018) between pregnant and open animals in the left (15.9 ± 1.7 vs 8.3 ± 1.2) but not in the right horn (12.4 ± 1.3 vs 12.4 ± 1.2). Progesterone effects were independent of CL quality (P = 0.55). Bilateral genital tract asymmetry in the cow affects progesterone, proteins and hexoses without altering pregnancy rates.


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