The role of sex steroid in two avian song behaviours differing in ontogenetic process

The male Bengalese finch,Lonchura striata, has two types of song behaviour (directed song, DS and undirected song, US). DS and US share a basically identical syllable repertoire, sequence pattern and tempo, but differ in the time course of appearance during the maturational process. In order to examine whether this results from a difference in testosterone (T) dependency, we studied developmental changes in the fecal T level and the amounts of DS and US during the 2–4 month period (N=7). DS appeared between 83 and 94 days of age, 4–16 days after a rise in the fecal T level. In contrast, US appeared earlier and at high frequency even when T was still at a very low level. These results suggest that DS is more dependent on the T level than US, and is not activated until the T level rises during the maturational process.     

畜禽血液甲状腺激素及其载体蛋白的研究进展

本文综述了近年来有关畜禽血液甲状腺激素及其载体蛋白的研究现状,就其检测原理、方法进行了分析,阐明了该研究的理论意义和广阔的应用前景,为畜禽育种工作提供了科学依据.     

中西医结合治疗原发性肾病综合症的临床研究

目的:观察中西医结合治疗原发性肾病综合症的临床疗效,并初步探讨其机理.方法:选择68例中医辨证为脾肾阳虚兼挟血瘀湿浊的PNS患者,随机分对照组33例,用标准激素治疗.治疗组35例,在标准激素治疗基础上加服中药汤剂.结果:治疗组能明显改善症状和体征,减少尿蛋白,降低血粘度及血脂水平(P均＜0.01).治疗组总有效率达91.42%,明显优于对照组78.78%(P＜0.01).     

Comparison of the time courses of luteinizing hormone (LH) secretion rates during continuous stimulation by LH-releasing hormone (LH-RH) in vivo and in vitro

Summary The patterns of LH secretion during constant stimulation of the pituitary glands of estradiol-treated ovariectomized rats with a maximally stimulating amount of LH-RH in vivo and in vitro correspond with each other qualitatively and quantitatively. In vitro the changes with time of the LH secretion rate are somewhat retarded, especially the occurrence of desensitization.     

In vitro biosynthesis of juvenile hormone III by the corpora allata ofCalliphora vomitoria and its role in ovarian maturation and sexual receptivity

Summary JH III is the only JH detected by GLC-MS in medium from in vitro incubations of corpora allata of adult females ofCalliphora vomitoria. When corpora allata were removed from females at various times during the reproductive cycle and the JH III produced by the glands in vitro measured by a JH III radioimmunoassay, an increase in the level of synthesis was found to occur before previtellogenesis (0–24 h). A second increase appeared at the onset of vitellogenesis (72–83 h) and continued until the end of vitellogenesis (96 h) and the occurrence of chorionation (120 h). Since sexual receptivity develops with vitellogenesis, the significantly higher levels of JH III biosynthesis in vitro at this time supports a possible role for JH in the acquisitive of receptivity.     

High potassium intake increases the plasma concentration and urinary excretion of vasopressin in the rat

Summary The effect of alterations of dietary potassium intake on the plasma concentration and the urinary excretion of vasopressin was studied in male rats. Ingestion of a high potassium diet resulted in increases in the plasma concentrations of potassium and vasopressin, systolic blood pressure, urine flow, and urinary vasopressin excretion. Ingestion of a low potassium diet had little effect on the plasma vasopressin concentration and systolic blood pressure but caused decreases in the plasma potassium concentration and urinary vasopressin excretion. The results indicate that physiological changes in the plasma potassium concentration or some other consequence of altered dietary potassium intake can affect vasopressin release and excretion.     

Increased responsiveness of the hypothalamic-pituitary axis to steroid feedback effects in ovariectomized rats treated neonatally with monosodium L-glutamate

Summary Chronic ovariectomized rats treated neonatally with MSG showed reduced circulating concentrations of LH coupled with elevated hypothalamic LHRH stores. Despite the apparent loss of LHRH secretion, the small pituitary glands showed an increased density of LHRH receptors and normal responsiveness to the releasing hormone. The positive feedback effects of progesterone on LH release in oestrogen-primed animals was greatly exaggerated reflecting the build-up of hypothalamic LHRH stores without loss of pituitary responsiveness to LHRH.     

Juvenilizing effect of ecdysone mimic RH 5849 inGalleria mellonella larvae

The response of the final instar larvae ofG. mellonella to topical application of the non-steroidal ecdysone mimic, RH 5849, was age-related as well as dose-dependent. In young final instar larvae, moderate doses of RH 5849 induced perfect supernumerary larval moults, but doses equal to and higher than 8.5 μg per larva caused premature formation of larval cuticle and were lethal. Application of RH 5849 significantly increased allatotropic activity of the brain, and also activated synthesis of juvenile hormone (JH) by the corpora cardiaca/corpora allata complex. Simultaneous application of RH 5849 and FMev, a potent inhibitor of JH synthesis, to young final instar larvae lowered the incidence of perfect supernumerary larval moults. We conclude that the effect of RH 5849 on the developmental programme inG. mellonella is mediated by the corpora allata.     

过度有氧运动对不同性别成年骨代谢相关激素的影响

为研究过度有氧运动对不同性别成年骨代谢相关激素的影响,选取某学院体育系的80名学生作为研究对象,其中男生40人,女生40人,随机将其划分成对照组和训练组,训练组受试者需进行大强度的健美操训练,对照组受试者在此期间不进行任何训练,针对不同性别的研究对象进行不同指标测试研究。实验发现训练组不同性别成年人实验后体重非常显著性低于实验前和对照组;脂肪百分比和瘦体重和实验前及对照组相比有显著性差异。长期过度有氧运动能够降低成年男性血睾酮含量,对骨代谢激素产生不利影响;同时,长期过度有氧运动会使女性骨代谢负平衡。因此,不建议成年人长期进行有氧过度运动。     

植物激素对海带孢子体发生的影响

采用析因试验设计,对影响海带孢子体发生的主要环境因子进行优化,筛选出温度8℃、光强30umol-m^-2·s^-1、光时12h的最佳环境条件．基于此条件,对吲哚乙酸（IAA）、赤霉素（GA,）、脱落酸（ABA）、激动素（KT）和矮壮素（CCC）等5种植物激素进行了初步筛选,结果表明0．1mg·L^-1IAA、2．0mg·L^-1KT对海带孢子体的发生有显著促进作用,0．5mg·L“IAA及0．1、0．5、1．0mg·L^-1ABA抑制孢子体的发生,GA3、CCC无显著的影响．采用拉丁方区组设计,对具有显著促进作用的KT进行浓度筛选,获得了促进孢子体发生的最佳浓度4mg·L^-1．在此条件下,孢子体于第5天发生,第16天发生率达94．2％±2．0％,孢子体发生显著加快．此外,孢子体发生与细胞增殖呈异速生长关系,并且连续光照斜率高于短光照,表明短光照更适合孢子体的发生．