湖羊和考力代羊公羔垂体－性腺轴系内分泌活动的差异

用放射免疫方法测定了湖羊和考力代羊公羔从初生到１８０日龄垂体内ＬＨ总量，血浆ＬＨ和睾酮浓度的变化。结果表明：湖羊从初生到９０日龄垂体内ＬＨ总量迅速上升（Ｐ＜０．０１），以后呈下降趋势；血浆ＬＨ浓度０～２０日龄较低（０．８９～１．０３ｍＩｕ／ｍｌ），３０日龄开始上升，９０日龄达到峰值（２．３４ｍＩＵ／ｍｌ），以后呈下降趋势。血浆睾酮从４０日龄起迅速上升，１２０日龄达到２．７３ｎｇ／ｍｌ，以后维持于高水平（２．３４～４．４４ｎｇ／ｍｌ）。考力代羊０～１８０日龄垂体内ＬＨ总量呈持续上升趋势（Ｐ＜０．０１），血浆ＬＨ水平０～８０日龄维持较低水平（０．５２±０．９９ｍＩｕ／ｍｌ），以后呈上升趋势；血浆睾酮水平０～１３０日龄很低（０．１９～１．１３ｎｇ／ｍｌ），１４０日龄开始上升。两品种比较，０～９０日龄湖羊垂体内的ＬＨ总量，血浆ＬＨ及睾酮水平均高于考力代羊。提示湖羊公羔性成熟早与其生后早期垂体合成和释放ＬＨ水平高有关。

THE DIFFERENCE OF ENDOCRINIC ACTIVITIES OF PITUITARY-TESTIS AXIS BETWEEN MALE LAMBS OF AND CORRIEDLE SHEEP

The levels of pituitary LH,blood plasma LH and testostrotrone(T) in Hu sheep male lambs(H) and Corriedle male lambe (C.) were measured by radioimmunoassay (RIA). The results showed that in H., pituitary LH levels increased sharply (P<0.01) from birth to day 90 and then gradully decreased. Blood plasma LH concentration was low from birth to day 20(0.89-1.03mlU/ml) ,started.to rise at day 30 and reached peak value(2.34 ±0.43mIU/ml) at day 90 and subsequently tended to be low. Blood plasma T level rapidly eleveted from day 40, reached 2.73±1.5ng/ml at day 120 and remained relatively high value(2.34-4.44ng/ml) afterwords. Levels of LH in pituitary and bath LH and T in plas- ma were higher in H. than in C. until day 90. These observations suggested that earlier sexual maturation of H. was related to its high level synthesis and secretion of pituitary LH in early postnatal period.