Blood samples were collected from primiparous sows via indwelling jugular cannulae at 15-min intervals for 12 h before and for 24 h (2 sows) or 48 h (10 sows) after weaning and then every 4 h until behavioural oestrus. Weaning to oestrus intervals ranged from 3 to 10 days and 2 sows showed no signs of oestrus and had not ovulated by Days 11 and 16 after weaning. Prolactin concentrations in plasma decreased significantly (P less than 0.001) and reached basal levels 1-2 h after weaning in all sows whilst plasma progesterone concentrations remained basal until approximately 30 h after the preovulatory LH surge in sows that ovulated. Elevated concentrations of prolactin or progesterone during the post-weaning period were, therefore, not responsible for delayed restoration of cyclicity. Overall, mean LH concentrations rose significantly (P less than 0.001) from 0.22 +/- 0.02 during the 12-h period before weaning to 0.38 +/- 0.03 ng/ml during the 12-h post-weaning period. After weaning, pulsatile and basal LH secretions were markedly increased for sows that showed an early return to oestrus (less than or equal to 4 days) compared with sows showing a longer weaning to oestrus interval but a correlation did not exist between either of these LH characteristics and the time taken to resume cyclicity. Mean LH concentrations before weaning were, however, inversely related (r = -0.649; P less than 0.05) to the weaning to oestrus interval. Overall, mean FSH concentrations rose significantly (P less than 0.001) from 151.1 +/- 6.2 (s.e.m.) ng/ml in the 12-h period immediately before weaning to 187.7 +/- 9.7 ng/ml in the subsequent 12-h period but there was no correlation between FSH concentrations, before or after weaning, and the interval from weaning to oestrus. However, a significant correlation was apparent between ovulation rate and peak concentrations of the rise in FSH after weaning (r = 0.746; P less than 0.05) and overall mean FSH values (r = 0.645; P less than 0.05). It is concluded that both LH and FSH concentrations in peripheral blood rose in response to removal of the suckling stimulus at weanling. The increase in LH pulse frequency associated with weaning was not directly related to the weaning to oestrus interval although a specific pattern of LH secretion was observed in sows showing an early return to oestrus (less than or equal to 4 days).(ABSTRACT TRUNCATED AT 400 WORDS)
Preovulatory changes in the steroidogenic function of primate granulosa cells were studied using the cyclic marmoset (Callithrix jacchus) as a model. Antral follicles (greater than or equal to 0.5 mm diameter) were dissected from mid-late follicular phase ovaries (7 days after prostaglandin-induced luteolysis) and classified by diameter as small (0.5-1.0 mm), medium (1.1-1.9 mm) or large (greater than or equal to 2.0 mm). Granulosa cells from follicles in each size category were isolated and pooled to assess steroid biosynthesis. The aromatase activity of freshly isolated granulosa cells from large follicles was 200 times greater than that of small follicles, confirming their relatively advanced preovulatory status. Granulosa cells were cultured for 48 h in the presence and absence of human (h) FSH (0.1 ng/ml), with and without 0.1 microM androgen (testosterone or 5 alpha-dihydrotestosterone), to assess basal and hormone-responsive steroidogenesis (progesterone accumulation in culture medium and aromatase activity in washed granulosa cell monolayers). Basal granulosa cell steroidogenesis increased with follicular size, and there was a development-related pattern of response to hFSH and androgen. hFSH responsiveness (maximum fold-stimulation induced by hFSH) declined with follicular size, being 2-6 times greater for granulosa cells from small vs. large follicles. On the other hand, hFSH sensitivity increased with follicular size; the dose of hFSH giving 50% of the maximum response (ED50) for cells from large follicles being 10-20 times less than that of cells from small follicles. For granulosa cells from small follicles, treatment with 0.1 microM androgen in the presence of hFSH led to dramatic (up to 16-fold) enhancement of steroidogenic responses to hFSH. In contrast, for granulosa cells from large follicles, the presence of androgen substantially inhibited aromatase activity stimulated by hFSH and had weak inhibitory effects on progesterone accumulation. These results show that granulosa cell steroidogenesis becomes increasingly sensitive to hFSH during preovulatory follicular development in marmosets. The marked ability of androgen to directly augment hFSH-responsive steroidogenesis in vitro is lost during preovulatory development, such that androgen acts in mature granulosa cells to suppress hFSH-stimulated aromatase activity. These observations are evidence of development-dependent changes in granulosa cell responses to FSH and androgens which may contribute to the control of preovulatory follicular development in primates.
The patterns of length alterations in the hand bones in cases of pseudohypoparathyroidism (PHP), pseudopseudohypoparathyroidism (PPHP), and acrodysostosis were evaluated. The length of each of the hand bones was measured and compared to appropriate means for age and sex. The pattern profiles thus generated showed that those for PHP and PPHP are almost identical, and are similar to that seen in acrodysostosis, except for the much smaller size of the bones seen in the latter condition. PHP and PPHP are probably differend manifestations of the same entity, and acrodysostosis may also be related to them. Brachydactyly E is indistinguishable radiologically from the PHP-PPHP syndrome.
The objective of this study was to determine whether faecal progestagen measurement could be used to diagnose pregnancy in wild black rhinoceros cows. Immunoreactive 20alpha-progestagens were measured in faecal samples collected regularly (one or two times times per week) from pregnant and non-pregnant wild black rhinoceros females (n = 6) in Zimbabwe. Fresh dung piles deposited by the study animals were serially sampled during prolonged periods of tracking with local game scouts. Samples were stored frozen, and dried prior to methanol extraction. Immunoreactivity in faecal extracts was measured with a 20alpha-dihydroprogesterone enzyme immunoassay and was shown to reflect circulating progesterone concentrations. Mean concentrations of faecal 20alpha-progestagens during each month of gestation were significantly higher than faecal concentrations in non-pregnant animals (P<0.05), except during the second month of gestation. Faecal 20alpha-progestagens remained 5-10 times higher than concentrations in non-pregnant animals from the 4th to 15th month of gestation. It was concluded that regular non-invasive reproductive monitoring of black rhinoceros in the wild was possible and that pregnancy could be accurately diagnosed from the measurement of 20alpha-progestagens in faecal samples. The use of this technique in wild black rhinoceros populations will offer new perspectives for in situ management of this endangered species.
The development of an enzymeimmunoassay for 5\g=b\-pregnanetriol and its use for non\x=req-\ invasive monitoring of reproductive cycles in Asian elephants is described. Gas chromatography\p=n-\massspectrometry (GCMS)
Factors regulating LH/hCG responsiveness in primate granulosa cells were examined in the marmoset monkey (Callithrix jacchus). Granulosa cells were isolated and pooled from small antral (0.5-1.0 mm) and large preovulatory (greater than or equal to 2 mm) follicles from mid- to late follicular phase ovaries of cyclic marmosets. The cells from small and large follicles were cultured in serum-free medium for 48 h in the absence or presence of increasing concentrations of hCG (0.1-100 ng/ml) with or without 0.1 microM androgen [testosterone or 5 alpha-dihydrotestosterone (DHT]). Granulosa cells from small follicles were also cultured in the absence or presence of a constant concentration of human FSH (30 ng/ml) with or without androgen for 48 h before exposure to hCG for an additional 48 h. Steroidogenic responsiveness was assessed by measuring progesterone accumulation in culture medium and aromatase activity in washed monolayers. Granulosa cells from large follicles showed dose-dependent increases in both progesterone accumulation and aromatase activity in response to treatment with hCG. In contrast, granulosa cells from small follicles were unresponsive to hCG. However, pretreatment of granulosa cells from small follicles for 48 h with FSH stimulated hCG responsiveness. The effects of both testosterone and DHT on hCG-stimulated aromatase activity and progesterone accumulation by granulosa cells from large preovulatory follicles were inhibitory. Testosterone and DHT also suppressed basal (no hCG) progesterone accumulation in these cells, but had no effect on basal aromatase activity. The effects of androgens on FSH-induced hCG responsiveness in immature granulosa cells were variable. The results show a development-related increase in marmoset granulosa cell responsiveness to LH/hCG and provide evidence that FSH and androgens interact to regulate the onset and expression of this critical event during preovulatory follicular development in the primate ovary.
The feasibility of monitoring ovarian function in scimitar-horned oryx (OFYX dammnh) by measurement of fecal 20a-progestagens was investigated. Fecal samples were collected daily or on alternate days over a 4-1 1 month period from five oryx during natural (n = 4) or synthetic PGF,, (cloprosteno1)-controlled (n = 1 ) cycles. Of the four oryx undergoing natural cycles, three had regular access to a vasectomised male, and mating dates were recorded. Ultrasonography was used to monitor changes in reproductive tract morphology in the female administered with cloprostenol. Neutral steroids were extracted from feces with methano1:petroleum ether (2: 1 viv) after first removing phenolic steroids with potassium hydroxide (1 M). The concentration of 20a-progestagens in the methanol phase was measured by enzymeimmunoassay. Excretion of 20a-progestagens in all females followed a cyclic pattern corresponding to the follicular and luteal phases of the ovarian cycle. Concentrations of fecal 20a-progestagens were on average twentyfold greater during the luteal phase compared with the follicular phase. Mean (t SD) ovarian cycle length, based on fecal progestagen profiles, was 24.4 * 2.2 days with mean (+SD) luteal and follicular phase lengths of 18.7 + 2.8 and 5.7 -C 1.6 days, respectively. Mating by a vasectomized male occurred when 20a-progestagen concentrations were still elevated or declining. Similarly, fecal progestagens did not return to follicular phase concentrations for 4-5 days after administration of cloprostenol, and a 4 day delay was observed between ovulation, as visualized by ultrasound scanning, and a rise in fecal 2Oa-progestagens. These data suggest a time lag of approximately 4 days between reproductive events and changes in fecal 20a-progestagen concentrations. We conclude that measurement of immunoreactive 20a-progestagen concentrations in feces has limited application for predicting ovulation or accurately timing inseminations because of delay in steroid excretion, but will enable noninvasive monitoring of ovarian cycles in scimitar-horned oryx for fertility assessment and for determining the outcome of artificial insemination programs.
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