Binding characteristics and regulation of the 17,20β,21-trihydroxy-4-pregnen-3-one (20β-S) receptor on testicular and sperm plasma membranes of spotted seatrout (Cynoscion nebulosus)

The binding characteristics of 17,20,21-trihydroxy-4-pregnen-3-one (20-S) to plasma membranes prepared from the testes and sperm of spotted seatrout (Cynoscion nebulosus) were investigated using a filtration method to retain the bound 20-S. A single class of high affinity (K_d = 17.9 nM), low capacity (B_max = 0.072 nM g^-1 testes) binding sites was identified by saturation and Scatchard analyses on testicular membranes of spermiating spotted seatrout. A corresponding receptor (K_d = 22.17 nM, B_max = 0.00261 nM ml^-1 milt) was also detected in spermatozoan membrane preparations. The rates of 20-S association and dissociation were rapid, both had T_halfs of less than 1 min. Competition studies indicated that the receptor was highly specific for 20-S. 17,20-dihydroxy-4-pregnen-3-one, which had the highest affinity of the other steroids tested, had a relative binding affinity (RBA) of 14.3%. Progesterone, 11-deoxycortisol and testosterone competed with an order of magnitude less affinity (RBA's of 7.4, 1.8 and 1.1%, respectively). Estradiol displayed low affinity for the receptor (RBA = 0.4%) and cortisol did not cause any displacement at 1000-fold excess concentration. Specific 20-S receptor binding was detected in plasma membranes from testes of both spermiating and non-spermiating seatrout and on spermatozoa. Prolonged incubation of testicular fragments from a spermiating fish with gonadotropin (15 IU ml^-1 human chorionic gonadotropin) or forskolin (10 µM) caused a 2–3 fold increase in membrane receptor binding. Previous studies have shown that gonadotropin-induced upregulation of the 20-S plasma membrane receptor in seatrout ovaries is required for the oocytes to become responsive to 20-S and undergo final maturation. The existence of a 20-S membrane receptor on sperm and its upregulation in the testes by gonadotropin raises the possibility that final maturation of spermatozoa in male seatrout may be regulated by a similar mechanism.     

鸡粪中雌激素的生物学测定

本试验选用性成熟前小白鼠59只,按体重随机分成四组,分别为烘干鸡粪组、鲜鸡粪组、药物处理组和空白对照组,其中烘干鸡粪组14只,其余三组均为15只,对照组和药物组喂以不含鸡粪的常规饲料,其中药物组用苯甲酸雌二醇肌注,鲜鸡粪组喂以含60％鲜鸡粪的饲料,干鸡粪组喂以含60％烘干后鸡粪的饲料试验结果表明,各组小白鼠子宫重量/体重存在极显著差异,其中空白组与各组比较差异极显著(P<0.01);干鸡粪组与鲜鸡粪饲料之间差异显著(P<0.05);干鸡粪组与药物组间差异极显著(P<0.01);鲜鸡粪饲料和药物组间差异显著(P<0.05),说明鸡粪中确实含有大量的雌激素样活性物质,在畜牧生产应用时应引起重视。     

粗酶制剂在大麦日粮中对产蛋鸡的影响

就粗酶制剂在大麦日粮中对产蛋鸡产蛋性能的影响进行了两次试验。按０．１％比例的酶制剂添加于含大麦２８．５％和５０％的日粮中，分别饲喂３３０和２４２日龄的产蛋鸡。结果添加酶制剂对鸡产蛋率无明显提高，而对每个蛋重和鸡蛋质量有所改善，同时使产蛋鸡外周血液中促甲状腺激素和生长激素显著提高，而使甲状腺素显著降低。     

Physiology Mechanism of Metabolisms in the Middle Scales of Lilium davidii var. unicolor Bulbs Stored at Low Temperature for Dormancy-Release

Changes in carbohydrate, phenols, free amino acids and endogenous hormones in middle scales of Lilium davidii var.unicolor bulbs during the 101 days storage at 2, 6 and 10℃ in moist sawdust were studied. The results indicated that as the storage time increased and the storage temperature delined, contents of starch and abscisic acid (ABA) decreased markedly, and the level of total soluble sugar, phenols, gibberellic acid (GA3) and indole acetic acid (IAA) increased sharply. In the first 34 days, the contents of the above substances changed most actively. Correlation analysis revealed that the increase in content of total soluble sugar and phenols was respectively caused by activation of amylase and phenylalanine ammonia-lyase (PAL). During the storage, the content of free amino acids decreased, and the level of arginine was the highest and changed most remarkably. According to the results of stepwise regression analysis and path analysis, we could primarily conclude that the metabolism of carbohydrates, phenols and free amino acids in the middle scales may be mainly regulated by endogenous GA3.     

Immunolocalization of sex steroid receptors in the epididymis and ductus deferens of immature and mature Japanese Quail, Coturnix Japonica

The goal of this study was to determine whether in the Japanese quail the male genital tract contains receptors for progesterone, androgen and estrogen (PR, AR and ER, respectively), which have significant roles in reproductive functions, and whether their localization changes during sexual maturation. The epididymis and ductus deferens (middle and ampulla regions) of immature (approximately 30-day-old) and mature male Japanese quail were collected and frozen sections of them were immunostained for PR, AR and ER. The immunoreaction products for AR and PR were found in the nuclei of epithelial cells in the efferent ductules, epididymal duct, and the middle and ampulla regions of the ductus deferens of mature and immature birds. In the mature birds, the epithelial cells of the efferent ductules, epididymal duct, and the middle and ampulla regions of the ductus deferens were positive for ER, although some of the cells in the ductus deferens were negative. The epithelial cells of the ductules in the epididymis stained positive for ER, but the immunoreactions were negligible in the ductus deferens of immature birds. These results suggest that the epididymis and ductus deferens in quail possesses PR, AR and ER receptors. Each receptor is expressed before sexual maturation, although enhancement of ER expression may occur during maturation.     

米糠日粮添加酶制剂对雏鹅代谢激素和生化指标的影响

7日龄雏鹅32只，随机分成对照组和试验组，饲以米糠（占30％）基因日粮，试验组添加0.2%的酶制剂。试验期为7－21日龄。21日龄时采取血样，测定其激素含量和生化指标。结果显示，（1）与对照相比较，酶制剂使雏鹅血液胰岛素水平升高40．82％（P＜0．01），血糖水平升高4．76％（P＞0．05），胰高血糖素水平降低31．18％（P＜0．01），胰岛素与胰高血糖素的比值升高104．18％（P＜0．01）；（2）血浆谷丙转氨酶活性较对照升高38．39％（P＜0．05），尿酸浓度下降10．60％（P＜0．05）；（3）血浆T3水平较对照升高24．42％（P＜0．05），促甲状腺激素水平下降8．85％（P＞0．05）。以上结果表明，酶制剂通过解除饲料中阿拉伯木聚糖等的抗营养作用，能影响机体代谢激素水平，改变糖和蛋白质的代谢，从而促进雏鹅的生长。     

环境温度对鸡饲粮代谢能测值及血浆中甲状腺激素浓度的影响

在5～35℃区间设六个温度条件,研究了环境温度对鸡饲粮干物质表观代谢率(ADMR)、干物质真代谢(TDMR)、表观代谢能(AME)、真代谢能(TME)及血液中甲状腺激素水平的影响,并探讨了干物质代谢率、内源性干物质(EDM)、内源性能量(EEL)排出量及代谢能等与血浆中甲状腺激素水平的关系。共用78只成年京白公鸡进行了测定。结果表明:环境温度显著影响ADMR、TDMR、EDM、EEL、AME、TME及血浆中三碘甲腺原氨酸(T_3)的水平。ADMR、AME、EDM、EEL、TDMR、TME、血浆中T_3浓度与环境温度关系呈曲线型。本试验还探讨了ADMR、AME、EDM、EEL、TDMR、TME与血浆中T_3浓度的关系,相关关系极显著,呈现出令人感兴趣的趋势,但对其进一步的生理机制有待深入研究。     

外源激素对油茶种子根系及轻基质嫁接容器苗生长的影响

以良种油茶种子和嫁接苗为试验材料,设计3种外源激素处理方式,探讨外源激素对油茶种子萌发、根系生长及油茶轻基质嫁接容器苗生长的影响。结果表明:适宜的激素处理对油茶种的根系生长、出芽和轻基质嫁接容器苗的生长具有促进作用。用50mg/L ABT处理过的油茶种子根系生长迅速、主根饱满健壮、须根浓密,发根质量好,Ⅱ级根出现早,须根出现和出芽时间比对照均提前7d左右。在轻基质嫁接容器苗株高生长和地径生长上具有显著的生长优势,可以在生产中推广使用。     

促花生长调节剂(Ethrel、PP333)和夏剪成花机理的初步研究

应用放射免疫法测定了IAA、ABA、CTK和C_2H_4等4种内激素的含量。结果表明,促花生长调节剂和夏剪处理的成花机理之一是造成枚条茎尖有利于花芽分化的激素环境,即CTK类物质和内源乙烯含量较高,ABA适中,生长物质(IAA—GA_3)含量下降,建立了一种以促花激素占优势的激素平衡系统。此结果为进一步揭示果树花芽分化机理和制定控制花芽分化的技术措施提供了重要的科学依据。     

不同激素对西伯利亚百合组织培养的研究

本文以西伯利亚百合不同外植体为试材,接种在培养基上(以NAA、6-BA两因素设计的9组不同培养基),进行愈伤诱导、出芽及生根。探讨不同因素对西伯利亚百合组织培养的影响,成功获得再生植株。结果表明,不同的激素浓度配比对西伯利亚百合组织培养会产生较大影响;愈伤的最佳诱导培养基为:(MS 0.05mg/L6-BA 0.2 mg/LNAA 0.8%琼脂 3%蔗糖);出芽最佳培养基为:(MS 0.05 mg/L6-BA 0.2 mg/LNAA 0.8%琼脂 3%蔗糖);其生根诱导最佳培养基为:(MS 0.2 mg/L6-BA 0.1mg/LNAA 0.8%琼脂 3%蔗糖)。