To understand the regulatory mechanisms of gonadotropin secretion in Rana rugulosa ,this study investigated the effects of dopamine (DA),estradiol (E 2) and testosterone (T) on the in vitro release of luteiniz...To understand the regulatory mechanisms of gonadotropin secretion in Rana rugulosa ,this study investigated the effects of dopamine (DA),estradiol (E 2) and testosterone (T) on the in vitro release of luteinizing hormone (LH) and follicle stimulating hormone (FSH) from the pituitary fragments of female Rana rugulosa using a static incubation system and radio immunoassay (RIA). The results indicated that DA at the concentration from 0 1?μmol/L to 10?μmol/L inhibited the release of LH and FSH from the pituitary fragments of sexually pre mature or hibernating individuals,and the inhibitory effects enhanced with increasing concentrations of DA. E 2 at 1?μmol/L and 10?μmol/L significantly stimulated the release of LH of sexually pre mature individuals,but inhibited their FSH release at 0 1?μmol/L to 10?μmol/L;T had no obvious effects on their FSH release,but significantly inhibited their LH release at 10?μmol/L. Neither E 2 nor T,at the concentration from 0 1?μmol/L to 100?μmol/L,had obvious effects on the release of LH and FSH of hibernating individuals. The data suggest that DA and sexual steroids may have direct regulatory actions on LH and FSH release at the pituitary level in Rana rugulosa ,and the action of sexual steroids may relate to the gonadal development stages (seasons).展开更多
以水解度(Degree of hydrolysis,DH)和ACE抑制活性为评价指标,筛选酶解鳖肉水溶蛋白的最适蛋白酶,考察酶解温度、酶解pH值和酶添加量3个因素的影响,以水解度为响应值,通过响应面优化得到最佳酶解工艺,并测定鳖肉水溶蛋白及其酶解物的氨...以水解度(Degree of hydrolysis,DH)和ACE抑制活性为评价指标,筛选酶解鳖肉水溶蛋白的最适蛋白酶,考察酶解温度、酶解pH值和酶添加量3个因素的影响,以水解度为响应值,通过响应面优化得到最佳酶解工艺,并测定鳖肉水溶蛋白及其酶解物的氨基酸组成与含量。结果表明,酶解鳖肉水溶蛋白的最佳工艺为:物料比(w/v)1:40、酶添加量8653 U/g、酶解温度38℃、酶解pH6.9、酶解时间4 h,验证实验所得酶解物的水解度为(64.94±0.17)%(n=3),与预测值61.93%相近。鳖肉水溶蛋白及其酶解物均含有17种氨基酸,必需氨基酸的含量符合WHO/FAO模型。酶解物的ACE抑制活性较未酶解时显著增强,丰富氨基酸的存在是鳖肉酶解产物发挥ACE抑制作用的重要基础。展开更多
文摘To understand the regulatory mechanisms of gonadotropin secretion in Rana rugulosa ,this study investigated the effects of dopamine (DA),estradiol (E 2) and testosterone (T) on the in vitro release of luteinizing hormone (LH) and follicle stimulating hormone (FSH) from the pituitary fragments of female Rana rugulosa using a static incubation system and radio immunoassay (RIA). The results indicated that DA at the concentration from 0 1?μmol/L to 10?μmol/L inhibited the release of LH and FSH from the pituitary fragments of sexually pre mature or hibernating individuals,and the inhibitory effects enhanced with increasing concentrations of DA. E 2 at 1?μmol/L and 10?μmol/L significantly stimulated the release of LH of sexually pre mature individuals,but inhibited their FSH release at 0 1?μmol/L to 10?μmol/L;T had no obvious effects on their FSH release,but significantly inhibited their LH release at 10?μmol/L. Neither E 2 nor T,at the concentration from 0 1?μmol/L to 100?μmol/L,had obvious effects on the release of LH and FSH of hibernating individuals. The data suggest that DA and sexual steroids may have direct regulatory actions on LH and FSH release at the pituitary level in Rana rugulosa ,and the action of sexual steroids may relate to the gonadal development stages (seasons).
文摘以水解度(Degree of hydrolysis,DH)和ACE抑制活性为评价指标,筛选酶解鳖肉水溶蛋白的最适蛋白酶,考察酶解温度、酶解pH值和酶添加量3个因素的影响,以水解度为响应值,通过响应面优化得到最佳酶解工艺,并测定鳖肉水溶蛋白及其酶解物的氨基酸组成与含量。结果表明,酶解鳖肉水溶蛋白的最佳工艺为:物料比(w/v)1:40、酶添加量8653 U/g、酶解温度38℃、酶解pH6.9、酶解时间4 h,验证实验所得酶解物的水解度为(64.94±0.17)%(n=3),与预测值61.93%相近。鳖肉水溶蛋白及其酶解物均含有17种氨基酸,必需氨基酸的含量符合WHO/FAO模型。酶解物的ACE抑制活性较未酶解时显著增强,丰富氨基酸的存在是鳖肉酶解产物发挥ACE抑制作用的重要基础。
