红三叶草总异黄酮对小公鸡生长及血清睾酮水平的影响

日粮中添加红三叶草总异黄酮（４．３８ｍｇ／ｋｇ饲料）,饲喂４５－５６日龄红布罗肉用公仔鸡,与对照组比较,总异黄酮实验组公仔鸡日增重提高５．１％,料重比下降９．２％,提高了饲料的利用率。屠宰结果表明,腹脂重、腹脂／胴体显著降低,鸡冠重、睾丸重增加,鸡冠、睾丸和体重间的相关分析,睾丸石蜡切片和血清睾酮含量的放射免疫测定,均表明总异黄酮能提高血清睾酮水平,促进雄性动物生殖系统发育。     

慢性低氧对雄性大鼠血浆皮质酮及睾酮水平的影响

目的:研究低氧对雄性大鼠性腺及相关激素水平的影响。方法:分别检测3km、5km及杭州海拔水平雄性大鼠睾丸和附睾指数、血浆皮质酮和睾酮水平。结果:3km组体重、睾酮含量均显著下降,睾丸指数、血浆皮质酮显著上升;5km组体重、附睾指数和睾酮含量均显著下降,皮质酮含量显著上升。结论:慢性低氧能显著影响雄性成年大鼠性腺及血浆睾酮水平,该结果显示哺乳动物在慢性低氧条件下生殖内分泌功能呈现抑制状态。     

雄性大鼠颌下腺雄激素受体表达及镉和丙酸睾酮对其的影响

目的探测雄性大鼠颌下腺内雄激素受体(AR)表达及细胞分布特征,了解氯化镉和丙酸睾酮对AR表达的影响。方法35只雄性Wistar大鼠分为3组:对照(C)组、镉(Cd)组和镉加丙酸睾酮(Cd T)组。利用免疫组化SABC法和图像分析系统作AR表达检测及平均光密度(AOD)值定量分析。结果AR在浆液性腺泡(AC)、颗粒曲管(GCT)、纹状管(SD)和排泄管等细胞内均有不同程度的表达,定位以细胞质为主。其中GCT细胞内AR的AOD值最高,SD次之,AC细胞最低。Cd处理24h后,三种细胞内AR的AOD值均见下降,7d时达最低水平,此后有所增加,但到30d时仍低于对照组(P<0.05)。Cd T处理后,GCT细胞内AR的AOD值明显增加。与3、7、15d时Cd组相比,差别均有显著性。AC和SD细胞内AR的AOD值虽高于相应时间点的Cd组,但两者比较仅在7d时差别有显著性。结论雄性大鼠颌下腺内广泛存在AR,镉可致颌下腺GCT、AC、SD细胞AR表达减少,补充雄激素可明显增加GCT细胞AR表达,但对AC和SD细胞AR表达的影响较小。     

睾酮对大鼠再生肝细胞核仁组织区影响的初步研究

以银染核仁组织区(argymphil nucleolar organiting regions,AgNORs)阳性颗粒数为指标,结合放射免疫技术,研究了大鼠部分肝切除(partial hepatectomy,PH)后,睾酮对余留肝细胞核仁组织区的影响。结果显示,pH后0～24h,各种方式(假手术、皮下注射芝麻油或睾酮)处理组,AgNORs数都下降,随后持续升高。在PH后48h和72h,低剂量(0．5ms／kg体重)睾酮对AgNORs数影响最显著,都明显高于其它两个睾酮处理组;中等剂量(2．5ms／kg体重)和高剂量睾酮(5ms／kg体重)处理对AgNORs数的影响与芝麻油处理组相比都无显著差异,但均高于假手术组;假手术后72h的AgNORs恢复到术前水平。血清睾酮含量测定显示,芝麻油处理组PH后0～48h睾酮持续下降,48h后不再下降,48h和72h时的睾酮浓度显著低于假手术组;低剂量处理,血清睾酮浓度在PH后0～24h下降,然后持续上升,在48h、72h达到假手术组的2～3倍;中等剂量和高剂量处理组,血清睾酮在PH后0～72h持续升高,是假手术组的6～7倍。以上结果初步表明,睾酮对PH后肝细胞中AgNORs的影响有两种情况：(1)在血清中的浓度是生理水平的2～3倍时,起促进作用;(2)6～7倍于生理水平时,基本无作用。     

睾丸去神经对大鼠半去势诱导的睾酮代偿性分泌的影响

在成年大鼠,半去势可以在促性腺激素没有明显改变的情况下导致睾丸静脉血液中睾酮浓度代偿性增加,其机理尚不明了。本研究以成年大鼠为实验动物,检验睾酮的代偿性增加是否受到睾丸去神经的影响。睾丸去神经（ｉｎｆｅｒｉｏｒ ｓｐｅｍａｔｉｃ ｎｅｒｖｅｓ,ＩＳＮ或ＩＳＮ ｐｌｕｓ ｓｕｐｅｒｉｏｒ ｓｐｅｒｍａｔｉｃ ｎｅｒｖｅｓ,ＩＳＮ－ＳＳＮ）手术２周后开始半去势实验,半去势之前和半去势之后６和２４ｈ,     

菟丝子对运动训练大鼠睾酮含量、物质代谢及抗运动疲劳能力的影响

本文以大强度耐力训练大鼠为模型,对菟丝子对运动训练大鼠睾酮含量、物质代谢及抗运动疲劳能力的影响进行了研究.试验中分别以1.16、2.32、6.96 g.kg-1.d-1的剂量给大鼠灌胃42d,并进行负重游泳实验、血清睾酮等生化指标测定.结果显示,菟丝子各剂量组力竭游泳时间长于运动对照组(T组)(P＜0.01);血清睾酮高于T组(P＜0.01),血清皮质酮低于T组(P＜0.05);各组间血清睾酮与皮质酮比值变化与睾酮变化较为一致;肝糖原(P＜0.05)、肌糖原(P＜0.01)高于T组;血清尿素氮低于T组(P＜0.05);血红蛋白高于T组(P＜0.05).从而表明补充菟丝子可以减轻大鼠血睾酮、皮质酮受高强度运动量的影响,维持在正常生理水平;促进蛋白质合成,抑制氨基酸和蛋白质分解,提高血红蛋白含量和糖原的储备,增强抗疲劳能力,具有多靶点、多途径的显著特点.     

雄性黄山短尾猴攻击行为和粪便睾酮水平季节性变化

睾酮对启动和维持雄性动物的性行为及保持雄性第二性征有重要作用,高浓度的睾酮还可促进雄性的攻击性。但是长时期维持高的睾酮水平还会使雄性付出很高的能量代价,所以雄性不会长时期地维持高的睾酮水平。本研究对黄山短尾猴鱼鳞坑YA2群雄性个体交配期（2006年9月-12月）与产仔期（2007年1月-4月）攻击行为进行研究,同时收集研究个体的新鲜粪便,并用放射免疫分析法测定粪便睾酮水平,以探讨雄性黄山短尾猴不同时期睾酮水平差异及睾酮水平与攻击行为的关系。结果表明,成年雄性黄山短尾猴攻击行为发生频次在交配期显著高于非交配期;成年雄性粪便睾酮水平在交配期显著高于非交配期;交配期成年雄性的粪便睾酮水平与攻击行为发生频次有较显著的正相关关系,而在非交配期无显著相关;低顺位个体在交配期和非交配期都没有观察到攻击行为。本研究的结果支持了“繁殖竞争假说”。     

慢性应激状态下大鼠睾酮水平测定

目的通过对于慢性应激模型和运动疲劳模型大鼠的血清睾酮水平的对比研究,探讨慢性应激过程中睾酮水平变化规律及其与发生疲劳的关系。方法建立大鼠慢性不可预测性应激模型及运动性疲劳模型;应用大鼠轨迹追踪系统对不同应激时间大鼠进行活动量观测,应用放射性免疫法对各组大鼠进行血清总睾酮和游离睾酮进行测定。结果与正常组比较,慢性应激大鼠第1周组活动量(运动轨迹长度,下同)增加(P0.01),第2周组活动量下降(P0.01)。各实验组大鼠游离睾酮与总睾酮之间均存在线性相关。慢性应激各组随应激时间延长,其游离睾酮与总睾酮比值呈逐渐下降趋势,并且能够达到运动疲劳组水平。结论慢性应激条件可以明显引起大鼠睾酮水平下降。提示分层检测慢性疲劳综合征人群血清总睾酮及游离睾酮的水平以及进行动态性研究可能为本病症的诊断提供生化指标。以游离睾酮与总睾酮比值为指标检测雄性激素水平,能够更好地反映干预因素对动物生理上的影响。     

雄性小熊猫粪便中睾酮水平的变化与繁殖周期的关系

1999 年12 月至2000 年9 月, 使用放射免疫分析法, 测定了成都动物园和成都大熊猫繁育研究基地的4 只雄性小熊猫粪样中睾酮水平变化情况, 同时对其行为进行了观察。研究结果表明, 雄性粪样中睾酮水平在繁殖期(12 月～3 月) 显著高于非繁殖期(4 月～9 月) (P < 0.01) , 且睾酮水平变化与繁殖行为密切相关。在非繁殖期,雄性小熊猫的睾酮水平处于基础的较低水平时, 其繁殖行为如蹭阴、舔阴、舔标记物和咩叫等几乎没有发生或很少发生; 而在繁殖期, 雄性小熊猫的睾酮水平明显升高, 这些繁殖行为频繁发生。以上结果说明, 睾酮是调节雄性小熊猫繁殖行为季节性变化的生理因子。     

日粮添加塞曼特罗（CIM）对大鼠生长胴体组成及GH水平的影响

选用２４只２月龄ＳＤ处女鼠配对分组,实验组日粮添加１０μｇ／ｇ塞曼特罗（ＣＩＭ）,试验期３０天。与对照组比较,ＣＩＭ显著提高大鼠生长速度（２７．３０％,Ｐ＜０．０１）和胴体比率,降低腰胁部脂肪重,提高腓肠肌、比目鱼肌和趾浅屈肌的鲜重和ＲＮＡ合量及ＰＮＡ／ＤＮＡ值,同时提高大鼠垂体和血清ＧＨ水平分别达３６．７０％（Ｐ＜０．０１）和２３．７７％（Ｐ＜０．０５）,降低血清脲氮含量。表明ＣＩＭ可显著促进大鼠生长,降低体脂含量,促进肌肉肥大,促进蛋白沉积。其作用机理可能还与其促进ＧＨ的合成和分泌有关。     

Effects of testosterone metabolites on copulation and medial preoptic dopamine release in castrated male rats

The medial preoptic area (MPOA) is an important integrative site for male sexual behavior. Dopamine (DA) is released in the MPOA of male rats shortly before and during copulation. The recent presence of testosterone (T) may be necessary for this precopulatory increase in release. Previously, the postcastration loss of copulatory ability mirrored the loss of the DA response to an estrous female, and the restoration of copulation with exogenous T was concurrent with the reemergence of this DA response. The present study investigated the effectiveness of the two major metabolites of T in maintaining copulation and basal and female-stimulated DA levels. Adult male rats were castrated and received daily injections of estradiol benzoate (EB), dihydrotestosterone benzoate (DHTB), EB + DHTB, testosterone propionate (TP), or oil vehicle for 3 weeks. Microdialysis samples were collected from the MPOA during baseline conditions, exposure to an estrous female behind a barrier, and copulation testing. EB + DHTB- and TP-treated animals had normal basal DA levels and showed a precopulatory DA response, and most copulated normally. EB-treated castrates had high basal DA levels, but failed to show a female-stimulated increase; most intromitted, but none ejaculated. DHTB- and oil-treated groups had low basal levels of extracellular DA that did not increase during copulation testing; most failed to mount and none ejaculated. These results suggest that E maintains normal basal levels of extracellular DA in the MPOA, which are sufficient for suboptimal copulation, but that androgen is required for the female-stimulated increase in DA release and for facilitation of ejaculation.     

Postparturitional testosterone surge in male offspring of rats stressed and/or fed ethanol during late pregnancy

Male offspring of rats exposed to restraint stress and/or alcohol during late pregnancy show aberrant patterns of sexual behavior masculinization and defeminization that vary as a function of treatment. The impact of these treatments on the postparturitional testosterone (T) surge that contributes to sexual behavior differentiation was investigated. Plasma T was measured using radioimmunoassay in individual males sampled on day 21 of gestation within 10 min of cesarean delivery or 1, 2, or 4 h thereafter. Neonatal T in the group exposed only to stress did not differ from that in the control group. T was lower than control levels at birth in both alcohol groups. The magnitude of the T surge that occurred during the first hour of birth in the control group was diminished by 50% in both alcohol groups, whose T pattern was very similar. There was no common alteration in postparturitional T associated with the increased lordotic behavior potential that males in all three treatment groups typically share, nor were there idiosyncratic endocrine abnormalities linked to the very different male copulatory pattern each exhibits. Exposure to an abnormal T milieu during fetal as well as neonatal ontogeny may underlie the etiology of the different sexual behavior patterns exhibited by males exposed to stress and/or alcohol. Possible unique effects each treatment exerts on perinatal plasma T and it's aromatization to estradiol in hypothalamic targets are discussed.     

Effects of egg yolk testosterone on growth and immunity in a precocial bird

In oviparous vertebrates, maternal steroid allocation to eggs can have important fitness consequences for the offspring. However, elevated testosterone levels are not only associated with beneficial postnatal effects, such as enhanced growth and high social status, but may also entail costs by suppressing the immune system. In this study, testosterone levels in eggs of Chinese painted quail (Coturnix chinensis) were experimentally manipulated to evaluate its effects on growth and immunocompetence. Testosterone did not affect embryonic development, body size or growth during the first 20 days. However, elevated testosterone levels during embryonic development were immunosuppressive for chicks with inherently higher growth rate. Adaptive scenarios where only beneficial effects of increased testosterone levels are considered may therefore need to be re-evaluated.     

Circadian variations in peripheral levels of growth hormone and testosterone in male Murrah buffaloes

The aim of this study was to investigate the endocrine profiles of growth hormone (GH), testosterone and their interrelationship in prepubertal, pubertal and orchiectomised male Murrah buffaloes under starving conditions. The prepubertal and pubertal buffaloes were subjected to frequent blood sampling over 24 h at an interval of 1 h, whereas in orchiectomised buffaloes, the blood samples were collected over 18 h. Irrespective of group, the GH concentrations fluctuated in an episodic manner over 24 h and the fluctuations did not exhibit a consistent pattern between the animals of each group. The mean basal and peak concentrations of GH did not differ significantly (p > 0.05) among the groups. A significant (p > 0.0001) difference in testosterone concentrations was observed between prepubertal and pubertal groups. The differences in mean basal and peak testosterone concentrations between the prepubertal and pubertal groups were also significant (p < 0.01). The associations between testosterone and GH levels in both prepubertal (r = 0.15; p > 0.05) and pubertal (r = ?0.37; p > 0.05) buffaloes were non-significant. The possible reasons for erratic episodic pattern of GH secretion will be discussed.     

白藜芦醇对成年期追赶生长大鼠体成分的影响及机制

目的:观察白藜芦醇对成年期追赶生长大鼠体成分的影响及可能机制。方法:8周龄雄性 SD 大鼠分为6组(共2个时间点),即4周时间点3组:正常饮食4周 (NC4)组、热卡限制4周(R4)组,热卡限制同时白藜芦醇治疗(R4E)组;12周时间点3组:正常饮食12周(NC12)组,追赶生长(CUG)组,追赶生长白藜芦醇治疗(CUGE)组。每组含6只大鼠,白藜芦醇用生理盐水配制成一定浓度悬浊液,按100 mg/(kg·d)剂量予实验动物灌胃治疗。实验第4周、12周检测体重、躯干和全身的肌肉及脂肪含量、躯干与全身脂肪比例,实验第12周检测骨骼肌与附睾脂肪组织SIRT1的表达,附睾脂肪组织PPARγ的表达。结果:与NC12组相比,CUG组躯干及全身的脂肪含量、躯干与全身脂肪比例、附睾脂肪组织PPARγ的表达均明显升高(P＜0.05),肌肉含量、骨骼肌与附睾脂肪组织SIRT1的表达显著降低(P＜0.05或P＜0.01);与CUG组相比,经白藜芦醇干预后的CUGE组全身的脂肪含量、躯干与全身脂肪比例、附睾脂肪组织PPARγ的表达均明显降低(P＜0.05),肌肉含量、骨骼肌与附睾脂肪组织SIRT1的表达较CUG组显著提高(P＜0.05)。结论:白藜芦醇降低成年期追赶生长大鼠体脂含量,增加肌肉含量,改善腹部脂肪堆积,其机制可能与增加骨骼肌及内脏脂肪组织SIRT1表达,抑制内脏脂肪PPARγ的表达有关。     

Probability of incubation by male Japanese Barn Swallows increases with plasma testosterone level

Empirical studies often support the notion that testosterone inhibits paternal behaviour in animals, although most studies have focused on high, as opposed to low, levels of paternal care. We studied the relationship between plasma testosterone levels and incubation in male Japanese Barn Swallows Hirundo rustica gutturalis, in which some males participate in incubation. Contrary to our prediction, the probability of incubation by males increased with plasma testosterone level. Male incubation behaviour might have emerged as part of nest monitoring behaviour by high-testosterone males in some subspecies that experience high nest predation rates.     

Effect of ipriflavone on glucocorticoid-induced osteoporosis in rats

Ipriflavone, 7-isopropoxy-3-phenyl-4H-1-benzopyran-4-one, was administered orally for 12 weeks to male rats with prednisolone-induced osteoporosis. Microdensitometric analysis of a roentgenograph of the femurs revealed that ipriflavone increased the density of the distal metaphysis dose-dependently and tended to increase the density of the diaphysis. It also inhibited dose-dependently the decrease in the mechanical strength of the tibia, breaking strain and breaking energy, and the fractional content of ash in femurs. These results indicate that ipriflavone markedly suppresses bone resorption at the metaphysis where the content of trabecular bone with a rapid turnover rate is high, and possibly inhibits bone reduction at the diaphysis.     

Social parameters and urinary testosterone level in male chimpanzees (Pan troglodytes)

Studies investigating relationships between social parameters (such as dominance rank, rates of aggressive and sexual behaviors) and androgen (particularly, testosterone) levels in male primates have yielded inconsistent results. In the present study, we address the relationship between androgens, male dominance rank and rank-associated behaviors in two groups of captive chimpanzees, a species characterized by a pronounced dominance hierarchy between adult males. By combining behavioral observations with urinary testosterone (T) measurements, we found that the differences in T concentrations between males were small and not obviously related to their dominance rank. T levels were not related to the rates of initiated aggression and copulatory behavior, but a significant negative relationship between male T level and the rates of strong aggression received was apparent. Our findings, combined with those of others, suggest that any relationship between dominance rank and T depends upon the extent to which individual rank-associated behaviors (e.g. aggressive/sexual) are themselves related to T.