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1.
Urine, feces, and copulation frequency were collected from two captive muriqui females, Brachyteles arachnoides, at the Centro de Primatologia do Rio de Janeiro following the resumption of postpartum ovarian cycles. Fecal steroid profiles from seven wild muriqui females at the Estação Biologica de Caratinga, Minas Gerais, Brazil, were compared to the captive females to determine the approximate patterns of steroid excretion relative to the urinary LH peak. Hormonal profiles from one of the captive female muriquis revealed a discrete urinary LH peak. For this female, fecal progesterone increased on the same day as the urinary LH peak, while fecal estradiol increased 6 days later and urinary steroids increased 5 days later. For both captive females, the onset of fecal progesterone increase was preceded by the onset of copulations, which occurred during at least a 5-day period. The complete fecal hormonal profiles of the one captive female for which continuous data were available were similar to those found in wild muriqui monkeys, with the onset of an increase in sustained progesterone levels occurring several days prior to the onset of sustained estradiol increase. These patterns suggest that fecal progesterone may be excreted rapidly in this species. The onset of sustained increase in fecal progesterone levels, together with the consistent delay in the onset of the sustained increase in estradiol, may provide the best indicators of the periovulatory period for muriqui females. Am. J. Primatol. 42:311–321, 1997. © 1997 Wiley-Liss, Inc.  相似文献   

2.
使用超声波技术检测了6只雌性四眼斑水龟的卵黄卵泡(包括生长卵泡和排卵前卵泡)、闭锁卵泡和输卵管卵的大小和数量.结果 表明:四眼斑水龟卵巢卵黄卵泡数目和大小呈明显的周期性变化,检测到的卵黄卵泡长径范围为4~24 mm(n=186).8月份卵泡数目开始增多,卵泡长径逐渐增大,至12月份排卵前期卵泡数量达最大值,卵巢发育成熟.排卵前期卵泡长径范围为19~24 mm(n=56),最大排卵前期卵泡出现于12月.排卵时间是1月至3月.闭锁卵泡长径范围在10~20 mm(n=14)之间,仅在10月至次年3月能检测到少数的闭锁卵泡.  相似文献   

3.
A direct immunoassay for urinary estrone conjugates (estrone sulfate and estrone glucuronide) was used to assess the preovulatory estrogen rise in normal gorilla menstrual cycles. Immunoreactive estrone conjugates in samples concomitantly assessed for total estrogen immunoreactivity reflected similar profiles throughout the cycle; however, the speed and resolution of the direct assay for conjugates indicate this method to be more accurate in monitoring ovulation than the measurement of total immunoreactive estrogens. In a single conceptive ovarian cycle, urinary estrone conjugate continued to rise in the luteal phase, indicating that this test may also be useful for detecting early pregnancy. The application of this technique provides clear profile of ovarian function in gorillas as well as in other primate species.  相似文献   

4.
The reproduction of the greeneye spurdog Squalus chloroculus was studied based on animals caught in the multispecies and multi‐gear southern and eastern scalefish and shark fishery on the upper continental slope off southern Australia. One hundred and ninety‐nine females (502–990 mm, total length, LT) and 189 males (515–810 mm LT) were examined. The female reproductive cycle, based on 41 breeding animals, is continuous and triennial, with the pregnancy period estimated to be 31–34 months, seasonal and synchronous with the ovarian cycle; a third of the breeding female population is estimated to give birth between September and December each year. The estimated LT at which 50% of females are mature is 799 mm (95% c.i. : 794, 804), whereas the LT at which 50% are maternal is 825 mm (95% c.i. : 817–833), but these estimates are probably biased by the phenomenon of apparent change of LT at maternity and LT at maturity following severe length‐selective fishing mortality. Litters ranged from four to 15 embryos with a 1:1 sex ratio, and litter size increased with maternal length. The breeding cycle of males is neither seasonal nor synchronous with the female cycle. The estimated LT of males where 50% are mature was 629 mm (95% c.i. : 603, 645).  相似文献   

5.
Few reports on the reproductive physiology of Cebus apella have been published. In this study we characterized menstrual cycle events by means of vaginal cytology, ultrasonography (US), and hormonal measurements in serum during three consecutive cycles in 10 females, and assessed the probability that ovulation would occur in the same ovary in consecutive cycles in 18 females. The lengths and phases of the cycles were determined according to vaginal cytology. Taking the first day of endometrial bleeding as the first day of the cycle, the mean cycle length +/- SEM was 19.5+/-0.4 days, with follicular and luteal phases lasting 8.2+/-0.2 and 11.3+/-0.4 days, respectively. The follicular phase included menstruation and the periovulatory period, which was characterized by the presence of a large number of superficial eosinophilic cells in the vaginal smear. The myometrium, endometrium, and ovaries were clearly distinguished on US examination. During each menstrual cycle a single follicle was recruited at random from either ovary. The follicle grew from 3 mm to a maximum diameter of 8-9 mm over the course of 8 days, in association with increasing estradiol (E(2)) serum levels (from 489+/-41 to 1600+/-92 pmol/L). At ovulation, the mean diameter of the dominant follicle usually decreased by >20%, 1 day after the maximum E(2) level was reached. Ovulation was associated with an abrupt fall in E(2), a decreased number of eosinophilic cells, the presence of leukocytes and intermediate cells in the vaginal smear, and a progressive increase in progesterone (P) levels that reached a maximum of 892+/-65 nmol/L on days 3-6 of the luteal phase. The menstrual cycle of Cebus apella differs in several temporal and quantitative aspects from that in humans and Old World primates, but it exhibits the same correlations between ovarian endocrine and morphologic parameters.  相似文献   

6.
We provide histological details of the development of oocytes in the cyprinodontid flagfish, Jordanella floridae. There are six stages of oogenesis: Oogonial proliferation, chromatin nucleolus, primary growth (previtellogenesis [PG]), secondary growth (vitellogenesis), oocyte maturation and ovulation. The ovarian lamellae are lined by a germinal epithelium composed of epithelial cells and scattered oogonia. During primary growth, the development of cortical alveoli and oil droplets, are initiated simultaneously. During secondary growth, yolk globules coalesce into a fluid mass. The full‐grown oocyte contains a large globule of fluid yolk. The germinal vesicle is at the animal pole, and the cortical alveoli and oil droplets are located at the periphery. The disposition of oil droplets at the vegetal pole of the germinal vesicle during late secondary growth stage is a unique characteristic. The follicular cell layer is composed initially of a single layer of squamous cells during early PG which become columnar during early vitellogenesis. During primary and secondary growth stages, filaments develop among the follicular cells and also around the micropyle. The filaments are seen extending from the zona pellucida after ovulation. During ovulation, a space is evident between the oocyte and the zona pellucida. Asynchronous spawning activity is confirmed by the observation that, after ovulation, the ovarian lamellae contain follicles in both primary and secondary growth stages; in contrast, when the seasonal activity of oogenesis and spawning ends, after ovulation, the ovarian lamellae contain only follicles in the primary growth stage. J. Morphol. 277:1339–1354, 2016. © 2016 Wiley Periodicals, Inc.  相似文献   

7.
In mammals, gonadal functions are regulated by two pituitary gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), that interact with gonadal membrane receptors to activate adenylate cyclase. In comparison to mammalian systems, in squamate reptiles a reduced amount of information exists on gonadotropins and their related receptors. This study is aimed at clarifying if, in the lizard Podarcis sicula, the ovarian sensitivity to FSH is correlated to the reproductive cycle and to the expression of membrane receptors involved in the hormone recognition. The results demonstrate that the ovarian adenylate cyclase responsiveness to FSH parallels ovarian functions, being maximal during the ovulatory period. The ovarian sensitivity to FSH is also related to oocyte growth and vitellogenesis. Northern blot analyses reveal that the FSH receptor mRNA is maximally expressed in vitellogenic oocytes during the reproductive period. These results suggest that, in lizard ovary, hormone activation of adenylate cyclase is mediated by de novo synthesis of receptors specifically involved in FSH recognition. In lizards treated in vivo with FSH during the pre-ovulatory period, adenylate cyclase becomes refractory to further FSH stimulation 2 hr after treatment, but sensitivity to the hormone is restored after 2 weeks. Nevertheless, while the restored level of activity never exceeds that observed during the nonreproductive period, the expression level of FSH receptor mRNAs is significantly enhanced in these animals. These results suggest that in lizard the processes that regulate ovarian growth, vitellogenesis, and ovulation are controlled by a complex network of signals including gonadotropin, FSH receptor expression, and adenylate cyclase.  相似文献   

8.
The role of sexual displays in mating strategies and their reliability in indicating the time of ovulation has given rise to multiple explanations in nonhuman primates. In order to discriminate among hypotheses, socio-sexual behaviors were recorded in a semifree ranging group of Tonkean macaques (Macaca tonkeana), together with sexual skin swelling volumes and measurements of urinary concentrations of estrone conjugates and pregnanediol glucuronide. A clear preovulatory peak of urinary estrogen levels occurred 2 days before a defined rise in pregnanediol glucuronide concentrations, indicating that both hormones pointed out the female's ovulatory period. The concept of estrus rightly could be applied to female Tonkean macaques since fluctuations in estrogen levels correlated with cyclic changes in genital swelling sizes and rates of female behavioral attractivity and proceptivity. Males proved to be capable of recognizing the optimal conception period as judged from the occurrence of maximal rates of following behavior, serial matings, and ejaculations during the peri-ovulatory phase. During this time, males succeeded in maintaining exclusive and enduring associations with females. However, consortships occurred precociously, with males starting to affiliate with females, follow, and mount them 1 week before the presumed time of ovulation. These long-lasting consortships appear to be a consequence of the female extended follicular phase. This presumably sexually selected character allowed females to extend conspicuous sexual displays: genital swelling and utterance of an estrous call, which might attract males' attention and arouse them. With regard to female mating tactics, the combination of reliably indicating the time of ovulation to the male and durable periods of competitor exclusion led to reject explanations assuming manipulation about paternity or long-lasting intermale competition incitement in Tonkean macaques. Competition for mates between females also turned out to be an irrelevant factor as it was very low in the species. We conclude that the main function of sexual displays is to herald the approach of ovulation toward available mates. Am. J. Primatol. 46:285–309, 1998. © 1998 Wiley-Liss, Inc.  相似文献   

9.
The feasibility of monitoring ovarian function in scimitar-horned oryx (Oryx dammah) by measurement of fecal 20α-progestagens was investigated. Fecal samples were collected daily or on alternate days over a 4–11 month period from five oryx during natural (n = 4) or synthetic PGF (cloprostenol)-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 methanol:petroleum ether (2:1 v/v) after first removing phenolic steroids with potassium hydroxide (1 M). The concentration of 20α-progestagens in the methanol phase was measured by enzymeimmunoassay. Excretion of 20α-progestagens in all females followed a cyclic pattern corresponding to the follicular and luteal phases of the ovarian cycle. Concentrations of fecal 20α-progestagens were on average twentyfold greater during the luteal phase compared with the follicular phase. Mean (±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 ± 1.6 days, respectively. Mating by a vasectomized male occurred when 20α-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 20α-progestagens. These data suggest a time lag of approximately 4 days between reproductive events and changes in fecal 20α-progestagen concentrations. We conclude that measurement of immunoreactive 20α-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. © 1995 Wiley-Liss, Inc.  相似文献   

10.
The histological analysis of eastern Atlantic bluefin tuna Thunnus thynnus ovaries caught from February to September 1999–2000, made it possible to distinguish the presence of seven oocyte developmental stages and allowed the characterization of six time-dependent ovary maturity stages. The ovaries of mature (fork length, L F ≥ 110 cm) bluefin tuna were non-active from August (spent period) to March (quiescent period) when they contained only perinucleolar-stage oocytes. Ovary development started in April to early May (recrudescent period) with the appearance of oocytes at the lipid stage. Vitellogenesis appeared in mid-May (ripening period) and post-vitellogenesis occurred in late May to mid-June (pre-spawning period). In late June to early July, hydrated oocytes, a sign of imminent spawning, were found only in specimens caught in Balearic waters. Females ranging between 100 and 110 cm L F, captured during the recrudescent and ripening periods, had the largest oocytes at the lipid stage, most of which were degenerating. An extensive vitellogenic atresia was observed in the ovaries of five females caught during the spawning period in non-spawning areas.  相似文献   

11.
The golden hamster has been described as exhibiting estrous cycle synchrony caused by social dominance. This has recently been reexamined by J. C. Schank (2000, Horm. Behav. 38, 94-101) with the aid of computer simulations. He concluded that there is no evidence for cycle synchrony among golden hamsters. In the present article we confirm this theoretical approach with the help of long-term experiments. Indeed, estrous cycle asynchrony was observed. Singly housed female golden hamsters in phase with their neighbors and in physical contact desynchronized their 4-day cycles after 2 or 3 weeks. Asynchrony was caused mainly by stochastic 5-day cycles. Statistical analysis was performed using a Monte-Carlo bootstrap approach. Based on the empirical data, an individual-based computer model was developed to simulate the dynamics of cycle desynchronization. Potential advantages were deduced for the population level. It emerged that estrous cycle asynchrony led to higher reproductive success for females where the probability of fertilization was low (e.g., after hibernation, poor habitat).  相似文献   

12.
Each of 32 crossbred beef heifers was brought from pasture on day 16 of its estrous cycle and assigned randomly to one of four treatment groups as follows: Field Control (FC), Field Dexamethasone (FD), Pen Control (PC), and Pen Dexamethasone (PD). Field groups were kept in a 0.8-ha field and pen groups were kept in 4.6-x 9.8-m pens in a pole barn during the trial. Dexamethasone (DEX) groups received 20 mg of DEX on cycle day 16 and 30 mg daily on days 17 through 20. Control heifers received an equal volume of physiological saline solution on corresponding cycle days. Average treatment cycle lengths (±SD) for control heifers in FC and PC groups were 21.1 ± 2.8 and 21.6 ± 1.8 days, respectively, and were not significantly different. Average time from progesterone decline (<1 ng/ml) to estrus was two days for each of the control groups. Four DEX-injected heifers had not shown estrus by day 44 of the treatment cycle. Progesterone had declined for two of these heifers by cycle day 18 and remained below 1 ng/ml past cycle day 48. The other two showed a decline in plasma progesterone by cycle days 18 and 32, respectively, and a progesterone rise by day 42 without having been detected in estrus. The remaining 12 DEX heifers had an average cycle length of 29.4 days. Four extended cycles resulted from extended CL function, five from an extended period from progesterone decline to estrus and three from a combination of these factors. These observations suggest that the administration of pharmacological doses of glucocorticoid during the late diestrus or early proestrus may result in altered ovarian function.  相似文献   

13.
The reproductive biology of female Norway lobster Nephrops norvegicus was studied throughout an annual cycle from January to December 2007 in Pagasitikos Gulf, a large semi-enclosed Gulf in the central west Aegean Sea, in Greece. Six ovarian maturation stages were described to follow gonadal development, based on the combined external observation and histological examination of the ovary. Reproduction showed clear seasonality both in terms of ovarian maturation and brooding period. The proportion of fully mature females in the catch increased from January to the summer months with a peak in June. The species has a protracted brooding period that peaks in November and December, while the release of eggs from females' pleopods occurs from January to March. The size at which 50% of females reached sexual maturity was estimated, using a logistic model, to be 28.1 mm of carapace length. The undiscovered reproductive dynamics will be valuable for optimizing population models and management strategies for this important fishery resource.  相似文献   

14.
We measured the concentration of steroid hormones from urine, feces, and blood samples of two captive Japanese macaques, Macaca fuscata, during nonconceptive ovarian cycles to compare the patterns of the excreted steroids with those of circulating steroids. Urine and feces were analyzed for estrone conjugates (E1C) and pregnanediol-3-glucronide (PdG) using enzyme immunoassays (EIAs), while plasma was analyzed for estradiol-17beta(E2), progesterone (P), and luteinizing hormone (LH) using radioimmunoassays (RIAs). Urinary and fecal E1C and PdG levels were approximately parallel to plasma E2 and P levels, respectively. The E1C profiles of daily urinary and fecal samples revealed a midcycle peak, followed by a sustained PdG increase lasting up to two weeks from the E1C peak. A fecal E1C peak was one day later than the urinary E1C peak. One of the captive females exhibited a discrete plasma LH peak, one indicator that ovulation has occurred, on the day following the urinary E1C peak, i.e., the same day of fecal E1C peak. We measured excreted steroids in nine wild females and determined the timing of ovulation by comparing fecal steroid profiles to those obtained in captive monkeys. Data from wild females indicated that eight of nine females conceived during their first ovulatory cycle of the sampling period, whereas the remaining female failed to conceive during the sampling period even though she ovulated. In the eight females that conceived, E1C increased again following the detected or estimated E1C peak, with levels comparable to the preovulatory peak levels, and sustained elevations of PdG for over 40 days. These data illustrate that the urinary and fecal profiles of ovarian steroid excretion obtained through the application of these noninvasive techniques provide an accurate approach for monitoring conceptive and nonconceptive ovarian cycle in captive and free-living Japanese macaques.  相似文献   

15.
Qualitative and quantitative investigations on the hemolymph proteins in the adult firebrat Thermobia domestica were performed during an ovarian cycle in inseminated and noninseminated females. Variations of hemolymph protein concentration were determined by Lowry's method. In addition, the proteins were studied by gradient slab gel electrophoresis using nondenaturing conditions and microdensitometry. Besides five major protein fractions, which are present in both sexes, three female-specific protein bands (vitellogenins) are found in the hemolymph and in maturing oocytes. These vitellogenins have molecular masses of 430, 300 and 240 kiloDalton. In fact, associated with the main 300-kD band, there were two smaller bands (320 and 280 kD) indistinguishable by densitometric measurement. Quantitative changes of vitellogenins are linked to oocyte maturation. These proteins appeared in the hemolymph before ecdysis, at the same time as the first yolk granules in the basal oocytes. They increased after ecdysis during the intense vitellogenic phase and decreased during chorion formation. In noninseminated females, in which all maturing oocytes are resorbed before chorion formation, the level of the 300 kD vitellogenins remained lower than in inseminated females. The quantity of vitellogenins fell only after complete oosorption. Thus insemination caused changes in the relative quantities of the different vitellogenic proteins.  相似文献   

16.
Transmembrane protein 14A (TMEM14A) is a member of TMEMs. Alterations in TMEMs expression have been identified in several types of cancer, but the expression and function of TMEM14A in ovarian cancer is still unclear. Here, analysis on the expression data of the Cancer Genome Atlas (TCGA) ovarian serous cystadenocarcinoma (OV) dataset demonstrated the overexpression of TMEM14A in ovarian cancer tissues compared with normal tissues, which was consistent with our real-time PCR analysis on ovarian cancer and normal tissues collected from 30 patients. In addition, TMEM14A knockdown in two ovarian cancer cell lines, A2780 and HO-8910, reduced cell proliferation, causes cell cycle arrest and suppressed cell invasion. Moreover, silencing of TMEM14A notably repressed G1/S cell cycle transition and cell invasion via down-regulating the expression of cell cycle related proteins (Cyclin D1, Cyclin E and PCNA) and metastasis-related proteins (MMP-2 and MMP-9), respectively. TMEM14A knockdown significantly reduced the phosphorylation status of Smad2 and Smad3, downstream effectors of TGF-β signalling. In summary, these results indicate that TMEM14A has a pro-tumorigenic effect in ovarian cancer cells, suggesting an important role of this protein in ovarian cancer oncogenesis and metastasis.  相似文献   

17.
The effect of propylene glycol drenching on ovarian and hormonal dynamics was studied in heifers. Five cycling heifers were used twice (as control and treatment) with crossover design. After the confirmation of ovulation (day 0), the heifers in the treatment group received propylene glycol on days 6, 7 and 8 as an oral drench (250 ml of 90% propylene glycol). On day 10, prostaglandin F2α (PGF2α), 15 mg per head of dinoprost, was administered intramuscularly to induce luteal regression followed by the follicular phase and then propylene glycol was again administered twice daily (500 ml/day) on days 10, 11 and 12. Palpation per rectum and ovarian ultrasonography were performed every other day from days 0 to 10, and daily after PGF2α administration until the subsequent ovulation (second ovulation) for analysis of follicular and luteal dynamics. Blood samples were also collected every other day from days 0 to 10, and then at 6 h intervals after PGF2α administration until the second ovulation. For the samples taken at 6-h intervals after PGF2α administration, the concentrations of glucose showed clear daily fluctuations in both groups. Changes in the plasma concentration of glucose in the treatment group were significantly (P < 0.05) higher than those of the control groups during the period between 0 and 72 h after PGF2α administration. No significant difference was detected in the growth of dominant follicles, maximum diameter of the ovulatory follicles and the changes in oestradiol and progesterone during the follicular phase between treatment and control groups. This study showed the clear daily fluctuations and stimulatory changes in the blood glucose concentrations at 24-h intervals during the short-term treatment of propylene glycol drenching in heifers. However, no significant changes in ovarian and hormonal dynamics were found under such metabolic conditions.  相似文献   

18.
An enzyme immunoassay (EIA) was applied to characterize the reproductive endocrinology of adult female black-handed spider monkeys (Ateles geoffroyi). Analysis of paired urine and fecal samples, collected from two females housed at San Diego Zoo, confirmed that the EIAs employed provided quantitative measurements of ovarian sex steroid hormones. Fecal metabolite levels were significantly correlated with those in urine, confirming that feces are a valid source of steroid metabolites in this species. The excretion of these metabolites in feces lagged urinary excretion by 1-2 days. The ovarian cycle profiles of the two captive females and five free-ranging females are comparable, with an average length of approximately 20-23 days. Cyclical bleeding, as previously reported, was observed in one of the two captive females. Pregnancy was detected in four free-ranging females, and early fetal loss for one female was indicated by hormonal data.  相似文献   

19.
Irregular menstrual cycles, reduced responses to exogenous hormonal treatments, and altered endocrine profiles (high FSH/high LH/low AMH) are observed in women with increasing age before menopause. In this study, because the granulosa cell‐specific Nrg1 knockout mice (gcNrg1KO) presented ovarian and endocrine phenotypes similar to older women, we sought to understand the mechanisms of ovarian aging and to develop a new strategy for improving fertility in older women prior to menopause. In the ovary of 6‐month‐old gcNrg1KO mice, follicular development was blocked in bilayer secondary follicles and heterogeneous cells accumulated in ovarian stroma. The heterogeneous cells in ovarian stroma were distinguished as two different types: (i) the LH receptor‐positive endocrine cells and (ii) actin‐rich fibrotic cells expressing collagen. Both the endocrine and fibrotic cells disappeared following long‐term treatment with a GnRH antagonist, indicating that the high levels of serum LH induced the survival of both cell types and the abnormal endocrine profile to reduce fertility. Moreover, follicular development to the antral stages was observed with reduced LH and the disappearance of the abnormal stromal cells. Mice treated with the GnRH antagonist regained normal, recurrent estrous cycles and continuously delivered pups for at least for 3 months. We conclude that endocrine and matrix alternations occur within the ovarian stroma with increasing age and that abolishing these alternations resets the cyclical release of LH. Thus, GnRH antagonist treatments might provide a new, noninvasive strategy for improving fertility in a subset of aging women before menopause.  相似文献   

20.
Cycle and gestation lengths, menstruation patterns, female genital swelling characteristics, and male-female consortship durations are reported in a semifree-ranging group of Tonkean macaques (Macaca tonkeana) studied over a 12 year period. In addition, profiles of urinary estrone conjugates (E1C) and immunoreactive pregnanediol glucuronide (PdG) throughout four complete menstrual cycles in two females and three full-term pregnancies are presented. Based on intermenstrual intervals, a mean cycle length of 37–41 days (n = 55 cycles in 10 females) was found. Gestation length averaged 173 days (n = 27 pregnancies in eight females). Measurement of PdG immunoreactivity in urine revealed a cyclic pattern with a 5–15-fold increase between follicular and luteal phase concentrations, suggesting that PdG is a reliable indicator of ovarian cyclicity and luteal function. In contrast to PdG, E1C excretion showed no clear pattern throughout the cycle; however, highest values of E1C were usually found shortly before the onset of the luteal phase PdG rise at the presumed time of ovulation. Levels of both hormones were elevated during the first half of gestation and showed a marked increase throughout the second half, with maximum E1C concentrations being up to 100-fold higher than nonpregnant levels. Consortships by the male and occurrence of female genital swelling were long lasting (on average 5–10 days and 13 days, respectively) and were restricted to the follicular phase of the cycle. The day of maximal swelling and day of detumescence as well as the end of male consortship were closely associated with the periovulatory period. Swellings and consortships were longer following lactational ammenorhea than for subsequent cycles. The evolutionary significance of the cyclical changes undergone by females upon their relations with males is discussed. © 1996 Wiley-Liss, Inc.  相似文献   

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