Diurnal variations of serum testosterone levels in intact and gonadectomized male and female rhesus monkeys.

A radioimmunoassay for serum testosterone which does not require chromatographic separation was used to measure the diurnal variations in intact and orchidecomized males and intact and ovariectomized females. The intact male rhesus monkey shows a distinctive diurnal variation in serum levels of testosterone characterized by lower values during the day and a marked increase in the early evening (1900-2200 hr). The testosterone levels remain high throughout most of the lights-off period in the intact male. In contrast to the intact male, the markedly lowered serum levels of testosterone in the orchidectomized male were higher during the day and consistently showed a nadir during the early evening (2000-2200 hr). The evening nadir of testosterone levels was 51.0% lower than the 24-hr mean whereas the maximum serum level was 46.4% higher. A similar circadian pattern of testosterone was seen in both the intact and ovariectomized females. The testosterone values were higher during the day and consistently showed a nadir during the early evening. These results suggest that the adrenal secretion of testosterone varies in a diurnal pattern characterized by an early evening nadir. This adrenal pattern is overshadowed by a much larger gonadal rhythm in the intact male.     

Developmental patterns of serum luteinizing hormone, gonadal and adrenal steroids in the sooty mangabey (Cercocebus atys)

Serum levels of luteinizing hormone (LH), testosterone, dehydroepiandrosterone sulfate (DHAS), androstenedione and cortisol were determined in multiple samples from 86 sooty mangabeys of varying ages (0-17 years). Testosterone, androstenedione, DHAS and cortisol were measured by radioimmunoassay; LH was determined by in vitro bioassay. Serum LH concentrations were elevated in neonates (less than 6 months) and in animals older than 72 months of age. The higher LH levels were associated with increased circulating concentrations of testosterone in males but not females. The pubertal rise in serum testosterone at approximately 55-60 months of age in males was coincident with rapid body growth. No pubertal growth spurt was observed in females. Serum levels of androstenedione and DHAS were highest during early postnatal life (less than 6 months) with androstenedione exceeding 600 ng/dl in males and 250 micrograms/dl in females, but declined rapidly in both sexes to a baseline of 150 ng/dl by 19 months of age. Serum androstenedione did not fluctuate significantly in adult animals. The pattern of age-related changes in serum DHAS paralleled those of serum androstenedione, whereas serum cortisol values did not change significantly with age. Developmental changes in serum LH, testosterone and body weight suggest that the sooty mangabey matures substantially later than the rhesus monkey. The pattern of serum gonadal and adrenal steroids during sexual maturation is similar to that seen in the baboon with no evidence of an adrenarche.     

Age- and gender-related changes in body size, adiposity, and endocrine and metabolic parameters in free-ranging rhesus macaques.

Normative age- and gender-related changes in body composition, serum lipids, testosterone, and insulin-like growth factor (IGF-1) were examined in the Cayo Santiago free-ranging rhesus macaques. In both adult males and females, body weights, crown-rump lengths, and circumference of the limbs were lowest in the oldest group (20+ years of age) as compared with other adult age classes. Body fat, as reflected in subcutaneous fatfold thickness and waist/thigh ratios, were higher in adult females than adult males. This gender dimorphism was first detectable among the 6-9 year old age group. Greatest body fat among females was observed in the 10-14 age group, whereas in males the highest values were observed in the 15-19 age group. Differences in body composition were also observed with respect to reproductive status. Although there were no gender differences in overall cholesterol levels, there were age-related differences between males and females, and only in males were cholesterol values positively related to adiposity. There were no age- or gender-related differences in triglyceride values, but levels were significantly higher in pregnant females in comparison with other reproductive states. Levels of testosterone were not significantly related to any morphometric parameter and values did not decrease significantly with age. Levels of IGF-1 exhibited a significant age-related decrease among adult males, and females had higher levels independent of age. The similarities between the present findings and human studies suggest that further studies in the free-ranging rhesus macaques would provide a bridge between studies of laboratory-housed primates and studies of human beings with respect to the etiology of obesity and life-history changes in body composition and endocrine and metabolic parameters.     

Determination ob biologically active LH in the serum of male rheusus monkeys (Macaca mulatta)

The in-vitro bioassay for LH, using mouse Leydig cells, has been modified for the direct measurement of serum LH in the male rhesus monkey. Validation of the assay demonstrated good reliability in terms of accuracy, precision and sensitivity (1.5 mi.u./ml). Basal LH concentrations in laboratory-maintained monkeys with and without anaesthesia were not significantly different from those in free-ranging, feral monkeys. LH-RH (50 micrograms i.v.) elicited a 30-fold increase in LH concentrations after 30 min. LH levels in castrated adult monkeys were approximately 50 times the normal levels. Intact and castrated juvenile males had only very low LH levels. LH from the serum of an adult male castrate was further characterized by Sephadex G100 column chromatography. The in-vitro bioassay provides a preferable alternative to the heterologous radioimmunoassay method for the routine determination of LH in the rhesus monkey.     

检测恒河猴血清中trastuzumab浓度的一种直接酶联免疫竞争法

采用ELISA法建立检测恒河猴血清中trastuzumab的酶联免疫竞争法,为研究人体内trastuzumab的药物动力学学和药效学提供依据。方法的测量范围是1～100μg／mL,最低检测限为1．0μg／mL。板内精密度范围91％～107％,相对标准偏差为1．5％～4．9％。板间精密度范围102％～110％,相对标准偏差为2．7％～15．4％。方法中未显示与重组人Ⅱ型肿瘤坏死因子受体-抗体融合蛋白、重组抗CD20单克隆抗体、丙种球蛋白等的交叉反应。此方法的特异性、灵敏度、精密度和准确度均满足恒河猴血清样品的分析,是检测猴和人体内trastuzumab的理想方法。     

猕猴神经干细胞的诱导分化、干性维持及同种脑内移植

为探索猕猴神经干细胞分化及特性维持,推进神经干细胞临床应用研究,该实验以绿色荧光蛋白(green fluorescence protein,GFP)为标记探讨猕猴胚胎干细胞向玫瑰花环(rosettes)结构神经干细胞的分化及其碱性成纤维细胞生长因子(basic fibroblast growth factor,bFGF)和表皮生长因子(epidermal growth factor,EGF)的扩增培养。结果表明:1)建立了稳定高效的猕猴神经干细胞分化体系,在该分化体系下,GFP标记猕猴胚胎干细胞在分化的第12天时,95%以上的细胞分化为神经干细胞;2)分化得到的Rosettes结构神经干细胞经bFGF/EGF扩增后,能够较好地维持其Rosettes结构;3)经bFGF/EGF扩增后的rosettes结构神经干细胞移植到猕猴脑内后能够较好的存活并向神经元分化,即bFGF/EGF扩增培养能较好地维持Rosettes结构的神经干细胞,且移植到猕猴脑内的该细胞亦能够较好地存活并向神经元分化,该结果为神经干细胞应用于临床提供了基础理论依据。     

Endocrine characterization of the menstrual cycle of the stumptailed monkey (Macaca arctoides).

The endocrine characterization of the menstrual cycle of the stumptailed monkey was determined and compared with that of the rhesus monkey. Serum concentrations of luteinizing hormone (LH), estradiol-17beta, and progesterone were determined on a daily basis from 5 monkeys. Differences included: 1) basal and peak concentrations of LH 40% of those in rhesus monkeys, 2) an estraidol peak occurring on the day proceding LH peak, 3) an estradiol peak on the 3rd day after LH surge and representing the highest mean estradiol value during the luteal phase, and 4) absence of the usual periovulatory decline in serum progesterone. Further experimentation is needed to understand the importance of these differences.     

Masses, centers-of-gravity, and moments-of-inertia of the body segments of the rhesus monkey (Macaca mulatta).

Segmental parameters (mass, center-of-gravity, and moment-of-inertia) are necessary for biomechanical analyses of a species' locomotor behavior. Seven male and eight female adult rhesus monkey cadavers were dismembered in order to determine segmental parameters. Mean values for the segment masses and moments-of-inertia are presented for males and females, separately and together. Statistical tests revealed significant differences between the sexes for these parameters. Regression equations for predicting segment masses and moments-on-inertia were developed for the sexes separately and pooled. For most segments the male and female equations did not differ significantly in slope or y-intercept. The center-of-gravity for each segment is presented as a mean percentage of the distance between the proximal and distal joint centers. The regression equations and center-of-gravity locations presented here permit biomechanical investigations of rhesus monkey locomotion without the necessity of subsequent sacrifice. The segmental parameter values determined for the rhesus monkey are compared with available data for other primate and mammalian species and the biomechanical and adaptive implications of such comparisons are discussed.     

Normal hematological and plasma biochemical parameters of the captive bonnet monkey (Maccaca radiata)

The bonnet monkey is being increasingly used as a model in biomedical research. However, unlike the rhesus monkey, very little information on the hematological and biochemical characteristics of blood plasma is available. Comparative data on plasma biochemical parameters vis-a-vis rhesus and human is essential for utilization of this species in biomedical research. Efforts were made to determine selected serum enzymes, glucose, triglycerides, blood urea nitrogen, creatinine, total protein, albumin, cholesterol, bilirubin, calcium, phosphorus, sodium, magnessium, potassium and total erythrocyte count, total leukocyte count, hemoglobin, PCV, ESR, and differential leukocyte count in groups of juvenile and adult bonnet monkeys of both sexes. The monkeys exhibited similar values for all the parameters in comparison to rhesus and human except for alkaline phosphatase. The value for alkaline phosphatase was 3–5 fold higher when compared to concentrations seen in rhesus monkeys and human beings. The investigation also describes the variations seen between adults and juveniles, as well as between the sexes. The data presented is valuable for scientists using this species of monkey as a human surrogate model.     

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.     

Steroid metabolism by monkey and human spermatozoa

Freshly ejaculated spermatozoa from monkey and human were washed and incubated with tritium labelled androgens or estradiol to study the pattern of spermatozoa steroid metabolism. When equal concentrations of steroid substrates were used for incubation, monkey and human spermatozoa showed very similar pattern of steroid conversion. Spermatozoa from both species converted testosterone mainly to androstenedione, but reverse conversion of androstenedione to testosterone was negligible. Estradiol-17 beta was converted mainly to estrone. The close similarity between the spermatozoa of monkey and men in their steroid metabolic pattern indicates that the rhesus monkey could be an useful animal model to study the effect of drugs on the metabolic pattern of human spermatozoa.     

Masses,centers-of-gravity,and moments-of-inertia of the body segments of the rhesus monkey (Macaca mulatta)

Segmental parameters (mass, center-of-gravity, and moment-of-inertia) are necessary for biomechanical analyses of a species' locomotor behavior. Seven male and eight female adult rhesus monkey cadavers were dismembered in order to determine segmental parameters. Mean values for the segment masses and moments-of-inertia are presented for males and females, separately and together. Statistical tests revealed significant differences between the sexes for these parameters. Regression equations for predicting segment masses and moments-of-inertia were developed for the sexes separately and pooled. For most segments the male and female equations did not differ significantly in slope or y-intercept. The center-of-gravity for each segment is presented as a mean percentage of the distance between the proximal and distal joint centers. The regression equations and center-of-gravity locations presented here permit biomechanical investigations of rhesus monkey locomotion without the necessity of subsequent sacrifice. The segmental parameter values determined for the rhesus monkey are compared with available data for other primate and mammalian species and the biomechanical and adaptive implications of such comparisons are discussed.     

A radioimmunoassay for dehydroepiandrosterone sulfate in the circulation of rhesus monkeys

A radioimmunoassay for dehydroepiandrosterone sulfate (DHAS) was established and validated for use in the rhesus monkey. The validation demonstrated the co-migration of immunoreactive material with tritiated dehydroepiandrosterone after hydrolysis and indicated the absence of other interfering steroids in the measurement. The application of this assay to perinatal samples verified that there are microgram quantities of DHAS present in the circulation. The measurement of circulating concentrations of DHAS in male and female rhesus monkeys at different stages of development demonstrated the absence of increases associated with puberty in this macaque species. Concentrations of DHAS were similar in adult males and females, but were elevated in pregnant females (p less than 0.05). Adult males had increased DHAS concentrations after GnRH administration (p less than 0.05), but no change was detected in infant male monkeys. Cortisol and DHAS responses of both infant and adult males occurred at a similar dose of ACTH (0.05 mU per kg versus 0.015 mU per kg, infant and adult, respectively). These data demonstrate the validity of the DHAS measurement in the rhesus monkey and suggest that the secretion of DHAS from infant and adult adrenals is generated by a similar stimulus. Since there was no evidence of gonadal secretion of DHAS in the infant, changes in either adrenal secretion and/or metabolic clearance of DHAS probably account for the microgram concentrations found during the perinatal period.     

X-ray induced translocations in premeiotic germ cells of monkeys

The induction of reciprocal translocations by various X-ray exposures was studied in spermatogonial stem cells of rhesus monkeys (Macaca mulatta) and stump-tailed macaques (Macaca arctoides) by means of spermatocyte analysis many cell generations after irradiation. The yields of translocations recovered from irradiated stump-tailed macaques were lower than those observed in rhesus monkeys and represent in fact the lowest induction rates per Gy ever recorded for experimental mammals. In the rhesus monkey a humped dose-effect relationship was found with (a) a homogeneous response with (pseudo-)linear kinetics below 1 Gy, (b) much more variability at higher doses, and (c) no induction at all at doses of 4 Gy and above. It is suggested that the post-irradiation proliferation differentiation pattern of surviving rhesus monkey spermatogonial stem cells i mainly responsible for these characteristics of the dose-response curve.     

Plasma insulin-like growth factor-I,testosterone and morphological changes in the growth of captive agile gibbons ( Hylobates agilis) from birth to adolescence

We examined growth changes in concentrations of plasma insulin-like growth factor-1 (IGF-1) and testosterone, and somatometric parameters in two captive male agile gibbons from birth to about 4 years of age, to examine the evolution of growth patterns in primates. Plasma IGF-1 concentrations in agile gibbons generally increased with age with values ranging from 200 to 1,100 ng/ml. The growth profiles in plasma IGF-1 in the gibbons were similar to those reported for chimpanzees. The highest concentrations of plasma testosterone (230 and 296 ng/dl) were observed within the first 0.3 years from birth, then the concentrations rapidly decreased and fluctuated below 100 ng/dl. Continuously higher IGF-1 concentrations were observed after 2.6 and 3.5 years of age. The profiles of plasma testosterone in these gibbons also resembled those of other primates including humans. However, their plasma testosterone levels in both neonate and adult stages (60 ng/dl) were lower than those reported for macaques and chimpanzees of respective stages. The obtained growth profiles of plasma IGF-1 and testosterone suggest that the adolescent phase starts around 2.6 or 3.5 years of age in male agile gibbons. The growth trend in many morphological parameters including body weight showed a linear increase without a significant growth spurt at approximately the onset of puberty. Head length and first digit length had reached a plateau during the study period. Brachial index, which indicates the relative length of forearm to upper arm, significantly increased gradually through the growth period. This result indicates that forearm becomes relatively longer than the upper arm with growth, which may be an evolutionary adaptation for brachiation.     

Serum leptin in nonpregnant and pregnant women and in old and new world nonhuman primates

Leptin is a hormone that is produced during mammalian pregnancy in the placental trophoblast and other tissues, including! fetal and maternal adipocytes. Synthesis of the polypeptide and the presence of its specific receptors throughout the human maternal fetoplacental unit suggest direct effects on conceptus growth and development. However, both the physiologic roles of leptin and the mechanisms regulating leptin synthesis in human pregnancy differ from those in laboratory and domestic species, necessitating the development of non-human primate research models. Therefore, we compared serum leptin concentrations in nonpregnant and pregnant women with those in both old world nonhuman primates (i.e., baboon, rhesus monkey, cynomolgus monkey) and new world nonhuman primates (i.e., squirrel monkey, titi monkey). As expected, maternal leptin levels were elevated in human and baboon pregnancies (P < 0.05 and P < 0.001, respectively). Levels in both species of old world monkeys were also greatly enhanced (P < 0.001). Although maternal serum concentrations were slightly elevated compared to nonpregnant levels in both species of new world monkeys, overall concentrations were dramatically lower than for either old world primates or humans. Results provide comparisons of serum leptin concentrations in pregnant and nonpregnant humans and baboons with those in both old and new world monkeys and further characterize these nonhuman primates as models for the investigation of leptin dynamics in pregnancy.     

Seasonal rhythm in plasma testosterone levels in the rhesus monkey (Macaca mulatta): A three year study

Behavioral and endocrine data were collected over a 3 yr period from a rhesus monkey breeding colony maintained in an outdoor enclosure. Routine data collection included recording all observed reproductive behavior and the date of all births. Blood samples were obtained at least once monthly from the sexually mature males in the group, and testosterone content determined via radioimmunoassay. The breeding group exhibited a seasonal pattern of mating and births such as is typical of the species. Copulatory activity was restricted to a 5 month period commencing in the early fall of each year, with all births recorded in a corresponding span between March and August. Plasma testosterone concentration showed a distinct seasonal rhythm, peaking each year in October or November at a mean of about 1200 ng/100 ml. During periods of sexual inactivity, plasma testosterone values fell to a low of about 200 ng/100 ml. The results demonstrate a correlation between seasonal breeding activity and increased levels of circulating testosterone in the rhesus monkey, and are supportive of the postulate that other seasonally observed behavior patterns (e.g., increased aggression) also may be mediated by higher testosterone levels.     

Susceptibility to postnatal growth retardation induced by 5-AZA-2'-deoxycytidine in utero: gender specificity and correlation with reduced insulin-like growth factor 1

The DNA demethylating agent 5-AZA-2'-deoxyxytidine (5-AZA-CdR) alters gene expression in mice exposed during developmental stages and causes malformations and growth suppression. The aim of this study was to determine if 5-AZA-CdR-induced growth retardation is associated with alterations in energy metabolism or in serum IGF-1 levels. Mice were exposed in utero to 5-AZA-CdR at gestation day 10. At postnatal day 21, exposed pups were weaned and body weights recorded. At 3 months of age, reproductive capacity was studied. At 5 months old, after body weight was recorded mice were killed and serum was collected to determine serum glucose, corticosterone, and IGF-1 levels. The body weights of both treated males and females were reduced at weaning compared with controls, but by 5 months of age, only the male body weight was affected. Reproductive capacity of males and females was reduced with males being more affected. Levels of corticosterone and glucose were not altered. Serum IGF-1 levels were lower in males exposed in utero to 5-AZA-CdR when compared to controls, but not in females, and correlated significantly with body weights. Our data suggest that the decreased levels of IGF-1 associated with the treatment could be the cause of the observed growth retardation in the in utero-exposed mice. A gender dimorphic effect, where males are more affected, is evident.     

Increased fertility in rhesus monkeys by breeding after the preovulatory LH surge.

Fertility in a rhesus monkey breeding colony was significantly increased by caging females with males immediately after detection of the preovulatory luteinizing hormone (LH) surge. LH was measured in daily serum samples by a rapid (24-hr) radioimmunoassay which used iodinated ovine LK as tracer and an antiserum to human LH.     

恒河猴piwil4基因的鉴定与表达分析

为了研究人类近亲恒河猴中PIWI家族蛋白PIWIL4的结构和表达情况,文章首次利用同源比对和RT-PCR方法克隆了恒河猴piwil4基因,检测了其mRNA在恒河猴心脏、脑、结肠、附睾和睾丸5种组织中的表达情况,利用生物信息学的方法对恒河猴piwil4基因和人的PIWIL4(HIWI2)基因编码的蛋白产物进行了同源性分析和结构域分析,并进一步利用免疫组化的方法比较了PIWIL4蛋白在成人、成年恒河猴和性未成熟恒河猴睾丸组织中的表达分布。结果表明,恒河猴piwil4 mRNA在多组织中表达,恒河猴和人的PIWIL4蛋白的氨基酸序列同源性达97%以上,均含有PAZ和Piwi结构域,它们在两物种成年个体睾丸组织中空间分布一致,但在不同发育阶段恒河猴睾丸组织中的分布发生了改变,幼猴中PIWIL4蛋白主要表达于生精小管细胞的细胞核,在成年猴睾丸组织中则表达于各种细胞的胞浆中。上述结果提示,piwil4基因在人类和恒河猴精子发生过程中作用类似,PIWIL4蛋白在幼猴和成年猴睾丸组织中的表达差异提示它们在不同发育阶段功能的改变。