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Summary. On Day 9 of pregnancy (day of mating = Day 1), the number of corpora lutea in the right ovary was greater than that in the left (mean ± s.e.m. 9·3 ± 0·1 and 6·5 ± 0·3 respectively; N = 70). Although the percentages of ova fertilized on the left and right side were not different (82% and 94%), the percentage wastage was higher on the left side (20%) than the right (14%). A significant difference in sperm numbers in the right (2·8 × 106) and the left (0·5 × 106) uterine horns were found 1·5 h after mating in 51 females. Morphometric measurements of the lower uterine luminal size showed that the right side (103·9 mm3) was larger than the left side (88·9 mm3; N = 5). It is obvious that there is structural and functional asymmetry in the ovary and uterus in the golden hamster.
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Summary. We have examined the effects of Sertoli cell-secreted proteins (SCSP) on [3H]thymidine incorporation by purified preparations (> 96%) of rat Leydig cells to determine whether Sertoli cells influence DNA synthesis in these cells in vitro. Incubation of Leydig cells isolated from testes of rats of ages 16 to 90 days with SCSP (M r > 10 000) induced significant dose-, time- and age-related increases in [3H]thymidine incorporation by the cells. A dose–response curve to SCSP showed that as little as 0·2 μg SCSP/ml consistently induced a small but significant increase (31% and 10% above control; P < 0·001) in [3H]thymidine incorporation by Leydig cells isolated from immature (26 days) and mature (70 days) rats, respectively. The maximum response (230% and 48% above control) was obtained with a concentration of 18 μg SCSP/ml in cells isolated from immature and mature rats, respectively. Hydroxyurea, a specific inhibitor of replicative DNA synthesis, significantly (P < 0·001) inhibited both basal and SCSP-induced [3H]thymidine incorporation in Leydig cells from immature and adult rats without affecting the viability of the cells. Incubation of immature rat Leydig cells in SCSP for 48 h also stimulated a 3-fold increase in cell number. The component of the crude SCSP which stimulated Leydig cell [3H]thymidine incorporation is trypsin-sensitive, heat-stable, and adsorbs to a heparin–agarose affinity column but not to concanavalin A–Sepharose. The secretion of this factor(s) by Sertoli cells is stimulated independently by FSH and testosterone. These results demonstrate for the first time that cultured Sertoli cells secrete a protein(s) which, in vitro, stimulates rat Leydig cell replicative DNA synthesis.
Keywords: testis; Sertoli cell; Leydig cell; DNA; rat
Dublin-Oxford Glycobiology Laboratory, School of Agriculture and Food Science, School of Veterinary Medicine, NIBRT – The National Institute for Bioprocessing Research and Training, Fosters Avenue, Mount Merrion, Blackrock, Co. Dublin, Ireland
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Follicular fluid (FF), an important microenvironment for the development of oocytes, contains many proteins that are glycosylated with N-linked glycans. This study aimed i) to present an initial analysis of the N-linked glycan profile of bovine FF using hydrophilic interaction liquid chromatography, anion exchange chromatography, high performance liquid chromatography (HPLC)-based separations and subsequent liquid chromatography–mass spectrometry/mass spectrometry analysis; ii) to determine differences in the N-glycan profile between FF from dominant and subordinate follicles from dairy heifers and lactating dairy cows and iii) to identify alterations in the N-glycan profile of FF during preovulatory follicle development using newly selected, differentiated (preovulatory) and luteinised dominant follicles from dairy heifers and lactating cows. We found that the majority of glycans on bovine FF are based on biantennary hypersialylated structures, where the glycans are sialylated on both the galactose and N-acetylglucosamine terminal sugars. A comparison of FF N-glycans from cows and heifers indicated higher levels of nonsialylated glycans with a lower proportion of sialylated glycans in cows than in heifers. Overall, as the follicle develops from Selection, Differentiation and Luteinisation in both cows and heifers, there is an overall decrease in sialylated structures on FF N-glycans.
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Summary. Antisera raised against the soluble antigens of the endometrium of early pregnancy detected two antigenic proteins of α1 and α2 mobility in extracts of this tissue and were termed antigens A and B. Neither antigen was detected in pregnancy sera or extracts of proliferative endometrium, but antigen B was detected in extracts of secretory endometrium and both were present in amniotic fluid and medium from in-vitro incubations of pregnancy endometrium. Fractionation of radiolabelled medium on ion-exchange chromatography demonstrated that antigens A and B co-eluted with the proteins from which EP14 and EP15 were derived and which were the major secretory polypeptides of pregnancy endometrium in vitro. Further biochemical purification revealed that EP14 (M r 32 000) was derived from a protein of native molecular weight 36 000 which existed in two forms, whereas EP15 (M r 28 000) was derived from a dimeric glycoprotein of native molecular weight 56 000. Immunochemical studies demonstrated that antigens A and B are identical to these two secretory proteins and have been termed pregnancy-associated endometrial α1- and α2-globulins (α1- and α2-PEG).
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Summary. The ventral prostates, dorsolateral prostates, coagulating glands, seminal vesicles and/or ampullary glands were bilaterally removed from adult male hamsters. Removal of these glands did not affect the fertilization rate and cleavage of the embryos at 48 h post coitum (p.c.). Air-dried preparations of the embryos showed a delay in cleavage at 72 h p.c. and a significant number of degenerated embryos was also found in females mated with males from which all the male accessory sex glands had been removed. A significant implantation loss was also observed at 122 h p.c. The results suggest that, in the golden hamster, removal of the male accessory sex gland causes a slower cleavage rate in embryonic development and a significant embryonic loss during pregnancy.
Keywords: accessory sex glands; embryo; cleavage; implantation; hamster
Departments of, Anatomy, Physiology, Medicine, Center of Heart, Centre of Growth, Brain and Healthy Aging
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Departments of, Anatomy, Physiology, Medicine, Center of Heart, Centre of Growth, Brain and Healthy Aging
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Departments of, Anatomy, Physiology, Medicine, Center of Heart, Centre of Growth, Brain and Healthy Aging
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Our laboratory previously showed that oviduct produced the greatest amount of adrenomedullin (ADM) in the rat female reproductive tract. The aim of this study is to investigate the changes in ADM levels resulting from the contact between the sperm and the oviduct and the possible roles of ADM in ciliary beating and oviductal contractility. Oviducts from Sprague–Dawley rats removed at pre- and post-ovulatory stages were cut open longitudinally and treated with ADM and/or receptor blockers before ciliary beat frequency (CBF) was measured. The effects of sperm on ADM production and CBF in the oviduct were also determined. The contraction of the oviduct after treatment with ADM and receptor antagonists was measured using the organ-bath technique. The results showed that ADM increased the CBF in rat oviduct and this stimulating effect was blocked by the calcitonin-gene-related peptide (CGRP) receptor antagonist, hCGRP8–37. CBF was lower in post-ovulatory than pre-ovulatory oviducts. The presence of sperm in the oviduct increased both the ADM level and CBF. ADM treatment was shown to inhibit the contractility of the oviduct by lowering the basal tone and decreasing the contraction amplitude. The ADM receptor antagonist, hADM22–52, was effective in counteracting the relaxation effect of ADM in the oviduct. All in all, these results indicate that ADM may play a crucial role in transporting the gametes/embryos by regulating ciliary beating and muscular contraction.
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Summary. Nineteen sulphonamides and related drugs were screened for their antifertility effects in male rats. They were suspended in corn oil and fed orally to rats at 10 times the human dose for a period of 6 months. Of the 19 compounds tested, sulphamethazine, sulphapyridine, dapsone, sulphamethoxypyridazine, sulphaguanidine, sulphathizole, sulphamerazine and sulphadimethoxine reduced fecundity of male rats to 34·3, 37·6, 38·3, 53·6, 55·6, 58, 75 and 78·6% of control, respectively. The fall in fecundity was due to a reduction in the number of embryos compared with the number of corpora lutea per pregnant female, and, in some cases, was associated with a fall in epididymal sperm concentration and motility. Some of these compounds accumulated in the cauda epididymidis at concentrations equal to or higher than the free drug concentrations in the blood. It is proposed that the antifertility effects of some of these compounds may in part be mediated through a direct effect on epididymal stored spermatozoa, hence compromising some processes vital for fertilization.
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In this review, we report permanent dysmorphogenesis of the penis and loss of fertility in adult rats treated neonatally with estrogen. Specifically, we report replacement of smooth muscle cells and cavernous spaces by fat cells in the corpus cavernosum penis, but not in the adjoining corpus spongiosum. Induction of these novel, region-specific phenotypes is dose-dependent, requires a critical window of exposure and associated with decreased testosterone and up-regulation of estrogen receptor α (ERα). The resistance of ERα knockout mice to develop these abnormalities implies an unequivocal role for ERα in mediating maldevelopment of the penis. Additionally, the prevention of estrogen-inducible penile abnormalities by ER antagonist ICI 182 780 implies that a functional ER-mediated pathway is essential for inducing penile abnormalities. Likewise, the ability of testosterone or dihydrotestosterone to negate these abnormalities suggests a role for an androgen receptor (AR)-mediated pathway. Taken together, these observations led us to hypothesize that neonatal estrogen exposure, via an ER-mediated pathway (direct action) or an AR-mediated pathway (indirect action through decreased testosterone) or both pathways, up-regulates ERα expression in stromal cells of the penis, which are then reprogrammed such that their differentiation into smooth muscle cells is inhibited and their differentiation into adipocytes is stimulated.
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The majority of ovarian cancers (>90%) are believed to derive from the ovarian surface epithelium (OSE); a single layer covering the entire surface of the ovary. At ovulation, the OSE cell layer undergoes an inflammatory response, involving cell death and growth, in order to overcome ovarian surface rupture. Abnormalities during these processes are believed to contribute to the development of tumours. Using primary cultures of OSE cells, we have compared anti-inflammatory and proliferative responses directly between human and ovine OSE cells to further establish the use of ovine OSE cells as a suitable model system for the study of human OSE cells. In order to compare effects of inflammatory stimulation, expression and activity of 11βhydroxysteroid dehydrogenase (11βHSD) type 1 was measured in OSE cells in response to interleukin (IL)-1α. As previously identified in human OSE cells, treatment of ovine OSE cells with IL-1α stimulated a concomitant increase of 11βHSD type 1 mRNA (31-fold; P < 0.05) and oxoreductase activity, indicating an increased production of anti-inflammatory cortisol. To compare the growth of human and ovine OSE cells, OSE cell number was measured in response to treatment with gonadotropins or growth factors. In the presence of FSH, LH or human chorionic gonadotropin (hCG), ovine and human OSE cell growth was similarly stimulated >1.2-fold (P < 0.05). In the presence of connective tissue growth factor (CTGF) and more significantly insulin growth factor I (IGF-I), human and ovine OSE cell growth was also similarly stimulated >1.2-fold (P < 0.05) and >1.5-fold (P < 0.01), respectively. The induction of both human and ovine OSE cell growth by IGF-I or hCG was further shown to be dependent on activation of the MAP kinase/extracellular-signal-regulated kinase (ERK) pathway. Stimulation of ovine OSE cell growth by hepatocyte growth factor (HGF) was similarly shown to be ERK-dependent; however, for human OSE cells, HGF only mildly stimulated ERK phosphorylation and failed to stimulate OSE cell growth. The demonstration that human and ovine OSE cells share similarities at the level of cell signalling, gene expression and cellular growth supports the use of ovine OSE cells as a suitable model for the study of human OSE cells.
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It is likely that the changes which occur in the endometrium throughout the menstrual cycle involve apoptosis, and that expression of associated genes, such as the bcl-2 family, are regulated by sex steroids. The aim of this study was to investigate the presence of bcl-2, Bax and oestrogen receptor proteins in secretory endometrium collected from ten patients with normal ovulatory cycles 4 or 6 days after the LH surge, and on the same days in a subsequent cycle in which the formation of secretory changes was inhibited by the administration of the antiprogestin mifepristone (RU486) 2 days after the onset of the LH surge. Since some stromal cells display positive immunoreactivity, leucocyte subpopulations of macrophages (CD68-positive) and large granular lymphocytes (CD56-positive) were identified in serial sections. After administration of mifepristone on day 2 after the LH surge, a significant increase in bcl-2 immunoreactivity was observed in glandular and surface epithelium. A positive correlation (0.874) with nuclear oestrogen receptor immunoreactivity in endometrial glands was demonstrated. Subsets of stromal cells, identified as CD68-positive macrophages and CD56-positive large granular lymphocytes displayed positive immunoreactivity for the bcl-2 epitope, which was unaffected by mifepristone administration. Bax immunostaining was similar in control and antiprogestin-treated endometrium. These data indicate that antiprogestin administration inhibits progesterone downregulation of steroid receptors in endometrial glands, resulting in persistence of a proliferative endometrium and accompanying bcl-2 secretion.
