We assessed the effects of social living (pairing) on improving the psychological well-being of adult female rhesus macaques (Mucuca mulutta) housed under laboratory conditions. We measured well-being in 12 pairs and 12 singly housed females through multiple indices of health (hematology, clinical morbidity, and body weight), stress (immune responses), behavior (preferences for social proximity, exhibition of species typical affliative behavior, and rates of abnormal behavior), and reproduction (frequency of ovulation, rates of conception, and infant survival). We selected adult females that had been living in single-unit cages and paired them in larger cages. Care was taken to allow females to become familiar with one another before pairing took place, and pairs that fought were separated before serious injuries occurred. Singly-housed control females were also paired for 1 week and then separated to balance the stressful effects expected to occur during the initial pairing and to assure that they were equivalent to the experimental animals in their ability to live socially. We concluded that pairing adult female rhesus monkeys was a positive experience for both the dominant and subordinate members of the pairs. They chose to spend the majority of their time involved in amicable social interactions, were more active, and they indulged in less nail biting than singly-housed controls. There were no differences in reproduction, rates of clinical morbidity, or immune stress responses among the groups. However, pairing alone may not be sufficient to assure the well-being of laboratory-housed rhesus macaques, because rates of abnormal behaviors such as stereotyped movements remained high. o
Serum follicle-stimulating hormone (FSH), pituitary FSH content and FSH beta subunit mRNA concentrations were measured at 1 to 3h intervals throughout the 4 day estrous cycle in rats. Serum FSH was stable (range 200-320 ng/ml) apart from the biphasic proestrus surge (5 fold elevation) which was present from 1800h of proestrus through 0800 h on estrus. Basal FSH beta mRNA concentrations from late metestrus through the afternoon of proestrus were 0.10 +/- 0.04 f mol cDNA bound/100 micrograms pituitary DNA. The major increase in FSH beta mRNA began at 2000 h on proestrus, 2 h after the initial rise in serum FSH and peak mRNA concentrations (0.43 +/- 0.08 f mol cDNA bound) occurred at 0200 h on estrus. FSH beta subunit mRNA concentrations were again increased at 2300 h on estrus (peak 0.24 f mol cDNA bound) and remained elevated through 1700 h on metestrus. Pituitary FSH content was transiently increased during metestrus and diestrus, but was elevated at 1000 h through 1900 h on proestrus (peak 5-fold increase). FSH content fell rapidly at 2000h and remained low until 1400 h on estrus when values again rose. These data show that FSH beta mRNA is increased 4-5 fold during the proestrus FSH surge, and a smaller increase occurs on metestrus in the absence of elevated FSH secretion. The increased concentrations of FSH beta mRNA occurred at different times to the previously reported changes in alpha and LH beta mRNAs. Therefore, the data suggest that different mechanisms are involved in the regulation of LH and FSH beta subunit gene expression during the 4-day estrous cycle in rats.
In this study, semen was obtained by rectal probe electrostimulation (RPE) from the Sulawesi crested black macaque (Macaca nigra). Three experimental series were conducted. First, semen was collected from four animals anesthetized with either tiletamine-zolazepam (TelazolB) or ketamine-HC1 (VetalarB) (five collections from each animal with each drug). Because of greater muscle relaxation and analgesia, we found tiletaminezolazepam to be an attractive alternative to ketamine-HC1 as an anesthetic agent for RPE in M. nigra. Second, semen was collected from another four animals at stimulation frequencies of either 30 Hz or 60 Hz (five collections from each animal at each frequency). There were no significant differences in sperm number, in percentage of sperm with progressive motility, in the current required for sample recovery between tiletaminezolazepam or ketamine-HC1 anesthesia, or between a 30 Hz or 60 Hz stimulation frequency. Third, to check for retrograde sperm loss, the bladders of four animals were emptied, flushed with sterile saline, and then infused with TALP-Hepes medium. After RPE, sperm numbers in the bladder were compared with those in the ejaculate. Although sperm were recovered from the bladder [1.6 (f 0.9) x lo6] (mean f SEMI, the numbers were significantly less (P < 0.05) than those in the ejaculate [49 (2 18) x lo6].The percentage of sperm with normal morphology in these samples was high (96.8 f 1.0%). The average sperm number in the 84 samples collected for this study was 33.8 (2 4.1) x lo6. In preliminary experiments, we found that M. nigra sperm will fertilize rhesus monkey oocytes (Macaca rnulatta) in vitro.
Testosterone (T) inhibits GnRH secretion and can also modulate the effects of GnRH on gonadotropin synthesis and secretion. To assess the effect of T on GnRH stimulation of alpha, LH beta, and FSH beta mRNA expression, we replaced T at three levels to reproduce low (1.5 +/- 0.5 ng/ml), medium (3.5 +/- 0.3 ng/ml), and high (6.2 +/- 0.6 ng/ml) physiological plasma concentrations. Additionally, as peripheral conversion to dihydrotestosterone (DHT) or estradiol (E2) may mediate T action, the effects of GnRH pulses in the presence of DHT and E2 were also studied. Male rats were castrated, and steroids were replaced via implants containing either T (three doses) or DHT or E2 (two doses each). GnRH pulses (10-250 ng/pulse) were administered iv at 30-min intervals for 48 h. Pituitary subunit mRNA concentrations, gonadotropin content, and LH and FSH secretion were determined. The patterns of alpha, LH beta, and FSH beta mRNA responses to increasing GnRH pulse amplitude were similar at all concentrations of plasma T. Alpha mRNA concentrations were increased 2- to 4-fold by GnRH pulses. At the same plasma T concentration, all doses of GnRH produced similar increases in alpha mRNA, but the response tended to be lower at the higher (6.2 ng/ml) levels of T. LH beta mRNA showed a clear dependence on GnRH pulse amplitude, with the maximum responses (2- to 3-fold) occurring after 10- to 25-ng GnRH pulses. At the higher (3.5 and 6.2 ng/ml) T concentrations, the dose-response curve was shifted to the left. The lowest GnRH pulse dose (10 ng) produced maximum responses, and LH beta mRNA increments in response to the higher GnRH doses were suppressed. FSH beta mRNA concentrations were increased by T in saline-pulsed controls. FSH beta mRNA responses were similar (2- to 3-fold) after all GnRH doses and at all concentrations of T. Increasing GnRH pulse doses reduced the pituitary content of both LH and FSH at all levels of T. Acute LH secretion was maximal after 10- and 25-ng pulses of GnRH when plasma T was low, but increased progressively with GnRH dose at the highest plasma T concentrations. Plasma FSH did not show any differential responsiveness to GnRH pulse dose or to increasing plasma T. Thus, LH synthesis and secretion are affected more than those of FSH by changing plasma concentrations of T. T may modulate posttranslational events in LH secretion. The higher GnRH doses effected LH release without increasing LH beta mRNA in the presence of higher physiological concentrations of T.(ABSTRACT TRUNCATED AT 400 WORDS)
Events in the normal menstrual cycle of the endangered Sulawesi Crested Black Macaque (Macaca nigra) were characterized. Daily blood samples were obtained during 10 menstrual cycles from five M. nigra demonstrating regular cycles. The amount of perineal tumescence was scored daily. Serum levels of estradiol and progesterone were determined by RIA, serum LH levels were determined by the mouse Leydig cell bioassay, and serum FSH levels were determined by the rat granulosa cell aromatase bioassay. Cycle length was 39.8 +/- 1.0 days (mean +/- SEM) with an LH surge occurring 25 +/- 1.5 days from the onset of menses. After menses, both LH and estradiol were initially depressed, with estradiol first exceeding 50 pg/ml 8 days before the LH surge. In five cycles, peak estradiol levels (340 +/- 44 pg/ml) occurred on the day of the LH surge (637 +/- 58 ng/ml) and in the other five cycles, on the day before the LH surge. There was a broad increase of FSH in midcycle without a well-defined surge corresponding to the LH surge. Progesterone began increasing on the day of the LH surge and reached peak levels (6.8 +/- 0.96 ng/ml) 8 days later. Maximal perineal tumescence was generally associated with the time of the LH surge, but variation between animals made it impossible to predict accurately the day of the LH surge by perineal tumescence scores alone.
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