Search Results
Search for other papers by F. R. BLATCHLEY in
Google Scholar
PubMed
Search for other papers by B. T. DONOVAN in
Google Scholar
PubMed
SUMMARY
In mated guinea-pigs one uterine horn was rendered sterile by ligation of the oviduct 2 or 3 days after finding spermatozoa in the vaginal smear. Two glass beads were inserted into the sterile horn on each of days 3–12 and on day 14 in experimental animals but not in controls. At autopsy on day 20 large corpora lutea were present in both ovaries of the control animals. The presence of beads that had been introduced on days 3 and 4 and on days 10–14 resulted in marked regression of the corpora lutea in the adjacent ovary, in the absence of a decidual reaction in the uterus, while luteal enlargement typical of pregnancy occurred in the contralateral ovary. Beads inserted on days 5–8 caused decidualization in the sterile horn but did not induce premature luteal regression in the ipsilateral ovary.
Search for other papers by A. P. Murdoch in
Google Scholar
PubMed
Search for other papers by P. J. Diggle in
Google Scholar
PubMed
Search for other papers by M. C. White in
Google Scholar
PubMed
Search for other papers by P. Kendall-Taylor in
Google Scholar
PubMed
Search for other papers by W. Dunlop in
Google Scholar
PubMed
ABSTRACT
Serum concentrations of LH are increased in polycystic ovary syndrome (PCOS). We have investigated two aspects of LH secretion which have not previously been reported: its reproducibility within individuals and the pattern of superimposed pulses of LH secretion. In nine patients with PCOS the mean concentration of LH was calculated from 24 blood samples taken at 15-min intervals for 6 h on two or three occasions over 1 year. Results showed differences in mean LH between subjects but reproducible concentrations within subjects over that period. It has been shown that LH is secreted in a complicated pattern of superimposed pulses which can be characterized by using the statistical methods of time-series analysis. To evaluate these pulse patterns of LH we studied nine patients with PCOS and compared the results with those of 12 normal women in the early follicular phase of the ovarian cycle. Blood samples were taken at either 5-min intervals for 6 h or 1-min intervals for 1 h. Pulses were detected in both groups at frequencies of about 1 h and 2 to 3 min. There was no significant difference in the pulse frequencies between the patients and controls but the amplitude of both groups of pulses was increased in the PCOS patients.
Journal of Endocrinology (1989) 121, 185–191
Search for other papers by B. Fisch in
Google Scholar
PubMed
Search for other papers by R. A. Margara in
Google Scholar
PubMed
Search for other papers by R. M. L. Winston in
Google Scholar
PubMed
Search for other papers by S. G. Hillier in
Google Scholar
PubMed
ABSTRACT
A primary monolayer cell culture system was developed to investigate human corpus luteum (CL) function in vitro. Steroidogenic cells were isolated by collagenase dispersal and Percoll density-gradient fractionation from CLs enucleated at progressive stages of the luteal phase (tubal surgery patients). 'Pure' granulosa-lutein cells were aspirated from ovulatory follicles at mid-cycle (in-vitro fertilization patients). The steroidogenic capacity (progesterone/20α-dihydroprogesterone biosynthesis and aromatase activity) of isolated luteal cells was assessed in relation to CL development. Basal luteal cell steroidogenesis was maximal at around the expected time of ovulation and declined with CL age during the luteal phase. Conversely, human chorionic gonadotrophin (hCG)-responsive steroidogenesis was initially undetectable but developed as the luteal phase progressed. These results show that luteal cell steroidogenesis becomes increasingly dependent upon gonadotrophic support with CL age. This is evidence that functional luteolysis in human ovaries (1) is pre-programmed to occur at the cellular level, (2) is initiated automatically at the time of ovulation and (3) is reversed at the time of CL 'rescue' in early pregnancy by the direct action of trophoblastic hCG on steroidogenic luteal cells. The culture system described should be of value in further defining the control of human CL form and function at the cellular level.
Journal of Endocrinology (1989) 122, 303–311
Search for other papers by P Bagavandoss in
Google Scholar
PubMed
The distribution of gelatinases/matrix metalloproteinases-2 and -9 (MMP-2 and MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in neonatal and gonadotropin-primed immature rat ovaries was studied by immunofluorescent microscopy. Immature female Long-Evans rats were primed with 15 IU pregnant mare's serum gonadotropin (PMSG) in 100 microliters PBS. Two days later, to induce ovulation, the rats were injected with human chorionic gonadotropin (hCG, 5 IU/100 microliters PBS). The animals were killed at appropriate times and the ovaries removed and processed for cryostat or paraffin sectioning. Ovaries were also obtained from 7-day-old neonatal rats and processed as above. In the neonatal rat ovary, MMP-2 was present in the follicle and in the ovarian surface epithelium. MMP-9 was not detectable in the neonatal ovary. TIMP-1 was present in the oocyte and in the surface epithelium. In the PMSG-primed ovary, MMP-2 was present in the granulosa and thecal cells of the ovary. MMP-9 distribution, however, was restricted to the interstitial and thecal cells. TIMP-1 was mainly present in the blood vessels and thecal cells, with minor staining in the granulosa cells. In the developing corpus luteum, luteal and endothelial cells were positive for MMP-2. MMP-9 localization was restricted to the plasma membrane of the luteal and interstitial cells. TIMP-1 was clearly observed in the luteal capillaries and, to a lesser extent, in the luteal cell plasma membrane. This distribution of MMP-2, MMP-9, and TIMP-1 in the corpus luteum persisted throughout the life span of the corpus luteum. The spatial and temporal distribution of the gelatinases and TIMP-1 suggests unique roles for these proteins in the rat ovary.
Search for other papers by B. ZONDEK in
Google Scholar
PubMed
Search for other papers by J. SKLOW in
Google Scholar
PubMed
Following the injection of chorionic gonadotrophin into immature female rats, oestrogen is produced in the ovary and passes into the circulation between the 26th and 27th hour after the injection. This has been shown in two experiments. First, if the injected rat is ovariectomized before the 26th hour, oestrus is inhibited, but if the ovaries are only removed 27 hr. after the gonadotrophin injection oestrus occurs normally [Zondek, 1940]. The time involved has been confirmed by experiments [Zondek, 1940; Zondek, Sulman & Sklow, 1941] in which antigonadotrophin has been injected into immature female rats at various times after injecting chorionic gonadotrophin. If the antihormone is given up to 26 hr. after the chorionic gonadotrophin the normal reactions of the rats (oestrus and the appearance of 'blood-points' and corpora lutea in the ovaries) are partially or completely inhibited, while if the antihormone is given 27 hr. after the gonadotrophin there is
Search for other papers by ESTHER C. JONES in
Google Scholar
PubMed
Search for other papers by P. L. KROHN in
Google Scholar
PubMed
SUMMARY
Hypophysectomy in the mouse (A, CBA, RIII and RIII × CBA strains) significantly retards, but does not wholly prevent, the normal progressive loss of oocytes from the ovary. The proportion of follicles judged to be normal on histological criteria rises from levels of 50–60% to levels of 60–75%. CBA strain mice which normally lose oocytes faster than the other strains still show this difference after hypophysectomy.
The extent to which the ovaries of hypophysectomized mice retain their normal function after more than 300 days in a gonadotrophin-free environment has been tested by transplanting them orthotopically into normal female hosts. In all cases, the grafts responded to gonadotrophin supplied by the new host and in the favourable environment provided by a young host produced normal litters as satisfactorily as transplanted normal ovaries.
Search for other papers by MC Botte in
Google Scholar
PubMed
Search for other papers by AM Chamagne in
Google Scholar
PubMed
Search for other papers by MC Carre in
Google Scholar
PubMed
Search for other papers by R Counis in
Google Scholar
PubMed
Search for other papers by ML Kottler in
Google Scholar
PubMed
The identification of gonadal gonadotropin-releasing hormone receptors (GnRH-R) and evidence of direct inhibitory effects of GnRH agonists upon steroidogenesis in adult rat gonads, lend credence to a putative intragonadal role of a locally secreted GnRH or GnRH-like peptide. Using reverse transcription-polymerase chain reaction followed by Southern blot hybridization and sequencing, we identified, both in the ovary and in the testis of fetal and adult rats, a fully processed GnRH messenger RNA (mRNA), the sequence of which, in adult testis, was identical to that found in the hypothalamus. We also detected in the testis, but not in the ovary, a transcript containing the first intron. The ontogeny of GnRH and GnRH-R gene expression was studied in rat gonads from 14.5 to 21.5 days post-coitum (dpc), using dot blot hybridization of total RNA. During this period, the levels of cyclophilin mRNA normalized to total RNA remained unchanged. Thus, we used cyclophilin as an internal standard. GnRH mRNA was detected in the ovary at 18.5 dpc, four days later than in the testis, and similar levels were found in both sexes at birth. GnRH-R mRNA was present at 14.5 dpc in the testis and at 15.5 dpc in the ovary, with the levels at 21.5 dpc being 2.4 times higher in the testis than in the ovary. GnRH and GnRH-R mRNA levels increased in both sexes in late fetal development, but this increase appeared two days sooner in the ovary compared with the testis, thus supporting the hypothesis that expression of the GnRH and GnRH-R genes is regulated in a sex-dependent manner during fetal development. In all cases, expression of GnRH and GnRH-R preceded gonadotropin receptors in the gonads and initiation of gonadotropin secretion by the pituitary.
Search for other papers by T. Sokka in
Google Scholar
PubMed
Search for other papers by I. Huhtaniemi in
Google Scholar
PubMed
ABSTRACT
The sequence of appearance of FSH and LH receptors, and response of cyclic AMP (cAMP) production to these hormones and cholera toxin, were studied in the fetal and neonatal rat ovary. Specific binding of radio-labelled human (h)FSH and chorionic gonadotrophin (CG) to ovarian homogenates was first detectable on day 7 of life. The content of FSH receptors per ovary increased tenfold between days 7 and 16, and that of LH receptors 27-fold. A significant response of cAMP production in vitro to FSH appeared on day 4 of life, but no significant effect of hCG on cAMP was achieved until day 7. In contrast, cholera toxin had a marked effect on cAMP production by day 17 of fetal life. Although both FSH and LH receptors were detectable in the neonatal rat ovary by day 7, the present findings indicate that the FSH responsiveness of the ovary appears earlier than that of LH. The post-receptor machinery of cAMP production is already functional in the fetal ovary as shown by the experiments with cholera toxin. The appearance of the receptor may therefore be the last link in the ontogeny of the gonadotrophin signal transduction system in the ovary. To study the hormone dependence of the appearance of gonadotrophin responsiveness, neonatal female rats were treated on days 1–6 or 1–9 of life with a potent gonadotrophin-releasing hormone antagonist, and killed on the following day. In both treatment groups, the pituitary LH and FSH contents were suppressed. The body weights remained unaltered, but ovarian weights decreased significantly during both periods of treatment (days 1–6,26·1%, P < 0·05; days 1–9,54·0%, P <0·001). No difference in basal or FSH-stimulated cAMP production was achieved by antagonist treatment for the first 6 days of life. The basal and hCG-stimulated rates of cAMP production per ovary were reduced in animals treated for 9 days (P <0·01), but the FSH-stimulated cAMP production remained unaffected. Hence, whereas the responsiveness to FSH seems to develop in the absence of normal gonadotrophin secretion, a causal relationship between normal gonadotrophin levels and the appearance of LH/hCG responsiveness is apparent in the neonatal rat ovary.
Journal of Endocrinology (1990) 127, 297–303
Search for other papers by R. M. OLIVER in
Google Scholar
PubMed
Search for other papers by P. A. FIELDS in
Google Scholar
PubMed
Search for other papers by L. H. LARKIN in
Google Scholar
PubMed
Polyacrylamide gel electrophoresis has been employed to separate three fractions that have relaxin activity from crude extracts of ovaries of pregnant sows. Bioassays indicated that all fractions had the ability to inhibit spontaneous uterine contractions in vitro and to induce formation of interpubic ligaments in oestrogen-primed mice. The presence of the various fractions in crude extracts of sow ovaries was monitored with the polyacrylamide gel system on days 40, 70 and 100 of pregnancy. Both the total amount and the relative proportions of the fractions were found to change as pregnancy progressed.
Search for other papers by ANITA M. MANDL in
Google Scholar
PubMed
Search for other papers by S. ZUCKERMAN in
Google Scholar
PubMed
The ovaries and adrenal glands of an adult rat hypertrophy after either ovarian or muscle tissue is homografted into the animal. The ovarian weight/body weight and adrenal weight/body weight ratios become significantly higher than those of normal adult female rats derived from the same colony. Anaesthesia also appears to lead to a transitory increase in the weight of the adrenals.
The possibility that the ovaries respond to certain non-specific conditions, in the same general way as do the adrenal glands, is discussed.
