Periodic fluctuations in FSH concentrations during the ovine estrous cycle

Heterologous radioimmunoassays for ovine LH and ovine FSH were validated and used to examine the concentrations of gonadotropins during the estrous cycle. Concentrations of LH were maximal on the day of estrus as previously reported. Concentrations of FSH were minimal 1 or 2 days before estrus, increased markedly during estrus, and fluctuated widely during diestrus. Most ewes ($\text{11}\text{13}$) had periodic waves of FSH occurring at short intervals (3.5–6 days, $\text{3}\text{13}\text{ewes}$), long intervals (10–18 days, $\text{3}\text{13}\text{ewes}$), or at both long and short intervals ($\text{5}\text{13}\text{ewes}$).     

多疣狭口蛙皮肤分泌物中FSH和LH的分离及在不同繁殖期的表达

运用聚丙烯酰胺凝胶电泳、葡聚糖凝胶层析、酶联免疫等实验方法,对多疣狭口蛙Kaloula verrucosa繁殖前期、繁殖期、繁殖后期的皮肤分泌物进行初步的成分分离,并对其不同时期皮肤分泌物成分中卵泡刺激素(Follicle stimulating hormone,FSH)及黄体生成素(Luteinizing hormone, LH)进行了免疫检测和定量比较.结果 表明:多疣狭口蛙皮肤分泌物中FSH的含量在其繁殖前期处于三个时期中的最高,繁殖期次之,繁殖后期最低;而LH则是在繁殖期含量最高,繁殖前期含量略偏低,到繁殖后期含量最低.     

Relationships between FSH surges and follicular waves during the estrous cycle in mares

Individual follicles >/=15 mm were monitored daily by ultrasonography in 12 mares during the estrous cycle. Follicular waves were designated as major waves (primary and secondary) and minor waves based on maximum diameter of the largest follicle of a wave (major waves, 34 to 47 mm; minor waves, 18 to 25 mm). Dominance of the largest follicle of major waves was indicated by a wide difference (mean, 18 mm) in maximum diameter relative to the second largest follicle. Dominant follicles of primary waves (n=12) emerged (attained 15 mm) at a mean of Day 12 and resulted in the ovulations associated with estrus (ovulation=Day 0). The dominant follicle of a secondary wave (n=1) emerged on Day 2 and subsequently ovulated in synchrony with the dominant follicle of the primary wave, which emerged on Day 9. The largest follicles of minor waves (n=4) emerged at a mean of Day 5, reached a mean maximum diameter 3 days later, and subsequently regressed. There was a significant increase in mean daily FSH concentrations either 6 days (primary wave) or 4 days (minor waves) before the emergence of a wave. Mean concentrations of FSH decreased significantly 2 days after emergence of the primary wave. Divergence between diameter of the dominant and largest subordinate follicle of the primary wave was indicated by a significantly greater mean diameter of the dominant follicle than of the largest subordinate follicle 3 days after wave emergence and by the cessation of growth of the largest subordinate follicle beginning 4 days after the emergence of a wave. Surges of FSH were identified in individual mares by a cycle-detection program; surges occurred every 3 to 7 days. Elevated mean FSH concentrations over the 6 days prior to emergence of the primary wave was attributable to a significantly greater frequency of individual FSH surges before wave emergence than after emergence and to an increase in magnitude of peak concentrations of FSH associated with individual surges.     

LH and FSH profiles at superovulation and embryo production in the cow

The variability of the superovulation response in cattle is an important problem to the commercial embryo transfer industry. Plasma LH and FSH concentrations around the time of estrus and ovulation were studied in relation to embryo production, to try and elucidate this problem. Sixteen cows were superovulated with 38 mg FSH-P and estrus synchronized with prostaglandin F(2) alpha. On the third and fourth day of superovulation increases in plasma LH but not FSH were detected. The LH and FSH profiles appeared to be normal in the size of the surge but in many cases they were were abnormal in timing. Transferable embryo production appeared to be lower in cows in which the LH and FSH surges were not coincident, and in cows where the surges were early or late with reference to estrus. FSH appeared to be primarily responsible for the number of embryos produced and LH for their quality, i.e. the number transferable.     

Validation of radioimmunoassays for LH and FSH in the sooty mangabey (Cercocebus atys): Characterization of LH and the response to GnRH

Heterologous radioimmunoassays (RIA) for macaque LH and FSH were validated for the measurement of these hormones in the sooty mangabey and mangabey pituitary LH was characterized relative to rhesus monkey LH. Dilutions of a pituitary mangabey extract and a partially purified preparation of mangabey LH ran parallel to a rhesus monkey standard (LER 1909-2) in the ovine-ovine (o-o) LH assay but showed some deviation from parallelism in the rhesus monkey FSH assay. The LH potency of the mangabey extract and standard were six and 190 times more potent, respectively, than LER 1909-2 in the LH RIA. Mangabey LH was estimated to have a molecular weight of 40,000–42,000 daltons vs 35,000–38,000 daltons for rhesus LH on Sephadex G-100 chromatography. Plasma levels of radioimmunoreactive LH, FSH, and testosterone were assayed before and after a bolus administration of 25, 50, or 100 μg synthetic go-nadotropin releasing hormone (GnRH) to adult male mangabeys. A significant increase in serum levels of LH was seen within 30 min with levels more than fourfold higher than the basal level of LH after administration of 100 μg GnRH. However, no consistent increases in plasma FSH values were detected. The integrated mean LH response above preinjection levels following 25, 50, or 100 μg GnRH was dose related. Serum levels of testosterone were also elevated after administration of GnRH, but peak concentrations of testosterone lagged behind peak levels of LH by approximately 30 min. These studies indicate that the heterologous RIAs may be used for measuring gonadotropins in the mangabey and that the male mangabey is apparently more sensitive to GnRH than the rhesus monkey.     

雌性恒河猴月经周期FSH、LH分泌水平的研究

本文采用改进的体外生物测定法分析恒河猴月经周期中促卵泡刺激素（ＦＳＨ）、促黄体生成素（ＬＨ）的变化情况。结果表明：雌猴的ＦＳＨ峰出现在月经周期的第１０２±１０天,峰值：５７２±４８ｎｇ／ｍｌ;ＬＨ峰出现在月经周期的第１２０±１６天,峰值：９６３±９７ｎｇ／ｍｌ,且为滤泡期、黄体期平均值的７～８倍。证实了在雌性恒河猴的月经周期中,其ＬＨ分泌高峰与ＦＳＨ分泌高峰不在同一时间出现的现象。     

Ultrastructural immunocytochemical localization of LH and FSH in the pituitary of the untreated male rat

Summary Rapid freeze-substitution fixation was employed in immunocytochemical studies on the localization of LH and FSH in the typical gonadotrophs of the anterior pituitary in the untreated male rat; a modification of a recently described ferritin antibody method (Inoue et al. 1982) was used in these studies. It was shown that rapid freeze-substitution fixation provides good preservation not only of the ultrastructure but also of the antigenicity. Both LH and FSH were clearly demonstrated in the same gonadotrophic cells, but the subcellular localization of these gonadotrophins differed: (i) LH was mainly located in small secretory granules, 250–300 nm in diameter; (ii) FSH was mainly present in large secretory granules, up to 500 nm in diameter. In the pituitary gland of the adult male rat, all gonadotrophs that react to antibodies against gonadotrophins are characterized by small and large secretory granules. Other types of cells of the anterior pituitary containing either small secretory granules or resembling corticotrophs with secretory granules assembled at cell periphery did not react to either anti-LH beta or anti-FSH beta serum.For light microscopy, the peroxidase antibody method was used. All of the gonadotrophin-positive cells contain both LH and FSH. None of the pituitary cells reacted to antibody against only one gonadotrophin. However, some cells are LH-rich while other cells are FSH-rich.     

Luteal blood flow during the estrous cycle in mares

Transrectal color Doppler ultrasound was used for the noninvasive investigation of luteal blood flow during the estrous cycle in six mares. Color was displayed in Power-Mode, in which the number of color pixels on the ultrasound image is related to the number of moving blood cells. Three pictures with a maximum number of color pixels of the corpus luteum (CL) during an examination period of about 20 min were selected and digitized on a laptop equipped with an external frame grabber card. The intra-class correlation coefficient for the number of color pixels was 0.90. In all estrous cycles similar patterns of changes in (C), in the cross-sectional area of sectional planes of the CL (A), and in plasma progesterone levels (P) occurred. Variance component estimates for the effect of the mare on (C), (A) and (P) were 14, 23 and 4%, for the influence of day of estrous cycle they were 41, 5 and 58% and for the effect of estrous cycle they were 7, 5 and 5%, respectively. There were high positive correlations between cyclic changes in (C) and (P) (r = 0.58; P < 0.0001). The increase in (C) between Days 0 and 5 (Day 0: ovulation) remained at high levels until Day 7 and then decreased until Day 15. There were relationships between (C) and (A) (r = 0.37; P < 0.0001) and between (A) and (P) (r = 0.24; P < 0.05), but correlation coefficients were not as high as between (C) and (P). Differences in (C), (A) and (P) between estrous cycles within mares and between mares were not related to each other (P > 0.05). The results show that transrectal color Doppler sonography is a useful, noninvasive method for examining luteal blood flow in mares, and that there are cyclic changes and individual differences in the vascularization of the CL. The possible influence of luteal perfusion on fertility in mares needs to be investigated in further studies.     

Associations between emergence of follicular waves and fluctuations in FSH concentrations during the estrous cycle in ewes

Folliculogenesis was studied daily in 16 interovulatory intervals in 5 Polypay ewes from mid February through April using transrectal ultrasonic imaging. The 3-mm follicles attaining > or = 5 mm on Days--1 (ovulation=Day 0) to 11 showed significant peak numbers on Days 0, 5 and 10. The number of 3- and 4-mm follicles that did not reach > 4 mm was not significant, indicating that these follicles did not manifest a wave pattern. A follicular wave was defined as one or more follicles growing to > or = 5 mm; the day the follicles were 3 mm was the day of wave emergence, and the first wave after ovulation was Wave 1. Waves 1, 2 and 3 emerged on Days -1 to 2,4 to 7 and 8 to 10, respectively. Four interovulatory intervals in April were short (9 to 14 d), indicating the end of the ovulatory season. In the remaining 12 intervals, the ovulatory wave was Wave 3 in one interval, Wave 4 in 8 intervals, and Wave 5 or 6 in 3 intervals. The ovulatory wave followed the rhythmic pattern of Waves 1 to 3 by emerging on Days 11 to 14 in 50% of the intervals. In the remaining intervals, either the ovulatory wave was Wave 4 but did not emerge until Day 16 or other waves intervened between Wave 3 and the ovulatory wave. The longest intervals (22, 24 and 24 d) had >4 waves. Based on a cycle-detection program, peak values of FSH fluctuations were temporally associated with the emergence of waves as indicated by the following: 1) tendency (P < 0.08) for an increase in FSH concentrations between 3 and 2 days before emergence of a wave; 2) close agreement between mean number of waves per interval (mean +/- SEM, 4.1 +/- 0.3) and mean number of identified FSH fluctuations (4.5 +/- 0.3); 3) close agreement in length of interwave intervals (4.0 +/- 0.3) and interpeak (FSH) intervals (3.6 +/- 0.2); 4) positive correlation (r(2)=0.8) for number of the 2 events (follicular waves and FSH fluctuations) within intervals; and 5) a closer (P < 0.01) temporal relationship between the 2 events than would have been expected if the events were independent. The results support a relationship between transient increases in FSH concentrations and emergence of follicular waves throughout the interovulatory interval in Polypay ewes, with the 2 events occurring approximately every 4 d.     

Treatment of ovariectomized ewes with bovine follicular fluid decreases secretion of FSH without changing secretion of LH

Ovariectomized ewes were injected with 0, 0.25, 0.5, 1.0 or 2.0 ml of charcoal-extracted bovine follicular fluid. Treating ewes with 2 ml of follicular fluid resulted in a decrease in circulating concentrations of FSH to 72.8% of the pretreatment value. With smaller doses of follicular fluid, the magnitude of the decrease was less. Concentrations of LH did not change significantly. Pretreatment of ovariectomized ewes with estradiol and/or progestogen did not alter the magnitude of the FSH decrease. This action of follicular fluid extract fits the effect of the non-steroidal substance known as inhibin or folliculostatin.     

Naloxone enhances LH but not FSH release during various phases of the estrous cycle in the ewe

Suffolk x whiteface ewes were infused with 0.5 mg/kg/hr naloxone hydrochloride (NAL) for 6 hrs during the early, mid and late luteal and early follicular phases of the estrous cycle. Basal serum luteinizing hormone (LH) concentration was increased by NAL during each trial in the luteal phase and LH pulse amplitude was proportionately increased by 158%, 164% and 350% during the early luteal, mid luteal and early follicular phases, respectively. The apparent NAL induced increase (92%) in LH pulse amplitude during the late luteal phase was not significant. NAL only affected LH pulse frequency during the early follicular phase, when it was decreased. Mean serum follicle stimulating hormone (FSH) concentration was not affected by NAL. The results of this study indicate that endogenous opioid peptides (EOPs) may partially mediate the suppressive influence of estradiol-17 beta (E2) on LH pulse amplitude and also the stimulatory effect of E2 on LH pulse frequency in the early follicular phase. The data may suggest that NAL enhances the amplitude of pulses of gonadotropin releasing hormone (GnRH) by counteracting E2 inhibitory effects on LH release at the level of the pituitary. Alternately, some component of E2 feedback may be an EOP mediated component at the level of the hypothalamus.     

FSH receptors in the bovine corpus luteum

Binding of follicle stimulating hormone (FSH) to a crude membrane fraction of bovine corpus luteum (CL) has been detected. This binding meets the usual criteria for a receptor based on specificity, time course of reaction and association constant (Ka = 8.5 x 10(10)M(-1)). Physiological studies with CL removed from heifers at specific times after estrus indicate that day-6 CL had the highest FSH binding. However, a correlation with physiological function was not obvious since some functional mid-cycle CL were high in progesterone and luteinizing hormone (LH) receptor but had nondetectable FSH receptor. Conversely, some late-cycle CL had low progesterone and LH receptor but significant quantities of FSH receptor.     

Delayed follicular development and ovulation following inhibition of FSH with equine follicular fluid in the mare

In two experiments, PGF(2alpha) was given to all mares on Day 10 (ovulation = Day 0). In experiment 1, mares received either whole follicular fluid or saline i.v. every 12 hours on Days 10 to 14. Experiment 2 was similar to experiment 1, except the follicular fluid was extracted with charcoal to remove steroids. Analysis of the FSH data for Days 10 to 21 indicated an effect of treatment (P<0.08) with whole follicular fluid, but not with charcoal-extracted follicular fluid. However, there was an effect of day (P<0.05) and an interaction (P<0.01) of treatment with day for both experiments. The interaction of treatment with day seemed primarily due to a marked post-treatment increase in FSH concentrations between Days 15 and 17 for mares treated with either whole follicular fluid or charcoal-extracted follicular fluid. Analysis of the diameter of the largest follicle for Days 10 to 18 indicated a main effect of treatment (P<0.05) and day (P<0.05) and an interaction (P<0.05) of treatment with day for both experiments. The interaction of treatment with day was attributable to the inhibition of follicular growth by Day 14 for mares treated with whole follicular fluid and by Day 15 for mares treated with charcoal-extracted follicular fluid. The length of the interovulatory interval was longer (P<0.05) in the treated group than in controls for both experiments. Results indicated that equine follicular fluid contained a proteinaceous substance that suppressed circulating concentration of FSH. The inhibited follicular growth and the delay in ovulation were attributed to the reduced concentrations of circulating FSH.     

Immunocytological localization of LH,FSH, TSH and their subunits in the pituitary of normal and anencephalic human fetuses

Summary Immunostaining with antisera to oLH, hCG, hLH, pLH, hFSH, hFSH, hTSH and bTSH was used to delineate the gonadotropic and thyrotropic cells of the human fetal anterior pituitary. Hypophyses from 29 normal fetuses, 3 newborn infants, and 5 totally ancencephalic fetuses were used. Several controls to check for the specificity of the immunocytological reaction were made.In normal fetuses, observations showed that: 1) the subunit was detected from the eighth week and throughout gestation without sex differences; 2) intact LH was detected during the third month, however, age and sex differences were observed during the fourth and fifth months; 3) intact FSH was detected in female fetuses from the beginning of the fourth month, a sex difference was observed; 4) LH and FSH were detected in the same cells; 5) the thyrotropic cells were detectable from 15 weeks of gestation and their number increased during gestation without sex difference; 6) at birth the gonadotropic cells were scarce and were located in the ventromedian zone of the anterior pituitary, while the thyrotropic cells remained numerous and were located in the dorsomedian zone.In anencephalic fetuses: 1) the subunit existed at each stage studied; 2) the reaction induced by anti-pLH and anti-hFSH sera was always very weak regardless of sex or age; 3) the thyrotropic cells were more numerous in comparison to the gonadotropic cells. These data are discussed in terms of the relationship of the hypophysiotropic hypothalamic factors to the appearance and evolution of the glycoprotein hormones and their subunits.     

Uterine and ovarian blood flow during the estrous cycle in mares

Uterine and ovarian blood flow was investigated in four mares during two consecutive estrous cycles using transrectal color Doppler sonography. The uterine and ovarian arteries of both sides were scanned to obtain waves of blood flow velocity. The pulsatility index (PI) reflected blood flow. There were significant time trends in PI values of all uterine and ovarian blood vessels during the estrous cycle (P < 0.05). PI values did not differ between the uterine arteries ipsi- and contralateral to the corpus luteum or the ovulatory follicle. PI values of the uterine arteries showed a wave shaped profile throughout the estrous cycle. The highest PI values occurred on Days 0 and 1 (Day 0 = ovulation) and around Day 11, and the lowest PI values were measured around Days 5 and -2 of the estrous cycle. During diestrus (Days 0-15) PI values of the ovarian artery ipsilateral to the corpus luteum were significantly lower than PI values of the contralateral ovarian artery (P < 0.0001). No differences (P > 0.05) in resistance to ovarian blood flow occurred between sides during estrus (Days -6 to -1). In this cycle stage PI values decreased in both ovarian vessels (P < 0.05). During diestrus, high PI values of the ovarian artery ipsilateral to the corpus luteum were measured between Days 0 and 2, followed by a decline until Day 6 (P < 0.05). From this time on, the resistance to blood flow increased continuously until Day 15 (P < 0.05). The cyclic blood flow pattern in the contralateral ovarian artery was similar to that in the uterine arteries (r = 0.68; P < 0.0001). No correlations occurred between the diameter of the corpus luteum and the PI values of the ipsilateral ovarian artery (P > 0.05) during diestrus. During estrus, there was a negative relationship between growth of the diameter of the ovulatory follicle and changes in PI values of the dominant ovarian artery (r = -0.41; P < 0.05). PI values of the uterine arteries and of the ovarian artery ipsilateral to the ovulatory follicle were negatively related to estrogen (E) levels in plasma during estrus (uterine arteries: r = -0.21; P < 0.05; dominant ovarian artery: r = -0.35; P < 0.05). In diestrus, PI values of the dominant ovarian artery were negatively related to plasma progesterone levels (r = -0.38; P < 0.0001), but not the PI values of the uterine arteries (P > 0.05). The findings of this study show that there are characteristic changes in blood supply of the uterus and the ovaries throughout the equine estrous cycle. There are negative correlations between resistance to blood flow in the uterine and ovarian arteries and the plasma estrogen levels during estrus. In diestrus, there is a negative relationship between the resistance to ovarian blood flow and the progesterone levels.     

Uterine contractile activity in mares during the estrous cycle and early pregnancy

Transrectal ultrasonography was used to quantitate uterine contractile activity during the estrous cycle and early pregnancy in pony mares (nonbred, n = 9; pregnant, n = 16). Continuous 1-min scans of longitudinal sections of the uterine body were videotaped, and uterine activity scores (1=minimal activity, 5=maximal activity) were assigned to each tape segment. There was a tendency (P<0.06) for a main effect of reproductive status (nonbred versus pregnant), a main effect of day (P<0.0001), and a reproductive status by day interaction (P<0.006). Uterine activity scores were higher (P<0.05) in pregnant mares on Days 1, 11, 12, and 17 (Day 0=day of ovulation) than in nonbred mares. Maximal activity in pregnant mares occurred on Days 11 to 14 during the reported period of maximal embryo mobility. Activity scores decreased (P<0.05) between the day prior to and the day of fixation (mean = Day 15) of the embryonic vesicle. Activity scores were maintained at an intermediate level for several days following fixation before declining to minimal levels by 7 d postfixation. A postovulatory decrease (P<0.04) in activity scores was observed in nonbred mares, but not in pregnant mares, between Days 0 and 1 followed by a progressive increase (P<0.03) between Days 2 and 4. Maximal activity in nonbred mares occurred during the late luteal phase (Days 13 to 14), corresponding temporally to the reported onset of luteolysis.     

Age-related differences in serum gonadotropin (FSH and LH), salivary testosterone, and 17-beta estradiol levels among Ache Amerindian males of Paraguay

Age-related differences in serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), salivary testosterone, and 17-beta estradiol levels are reported for Ache Amerindian males (n = 17; mean age, 37.1 +/- 14.2 SD) of Paraguay in order to explore population variation in patterns of male reproductive senescence in a foraging/agricultural community. Hormone associations were examined to test various hypotheses for age-related differences in hypothalamic-pituitary function. Significant increases in FSH (r = 0.75, P < 0.0005) and LH (r = 0.65, P < 0.01) were noted in association with aging. No significant correlation was observed between morning or evening testosterone and age. Morning and evening estradiol levels were associated with morning and evening testosterone, respectively (morning, r = 0.53, P = 0.05; evening, r = 0.63, P = 0.02). Evening estradiol was also positively associated with LH (r = 0.66, P = 0.02), suggesting testicular production to be an important source of circulating estradiol. Morning estradiol tended to rise with age, but was not significant (r = 0.39, P = 0.15). Anthropometric measurements of height, weight, body mass index, and fat percent did not change significantly with age. In contrast to testosterone, age-related differences in gonadotropin levels may be independent of energetic status, less variant, and more universal among male populations. Implications for gonadotropin function and aging on human male reproductive senescence and life histories are discussed.