摘要
在春季选用7头土种处女山羊,每天分三次皮下注射17β-雌二醇(E_2)0.5mg/kg体重和孕酮(P)1.25mg/kg体重,连续7天。在诱发过程不同时期,取静脉血样用RIA方法同批测定血清中E_2、P及催乳素(PRL)含量。同时测定乳腺组织样品的RNA和DNA含量。诱发过程中、乳腺外观逐渐发育,第15天左右出现初乳样分泌物,约第20天开始泌乳,与RNA/DNA值表现一致。各期RNA/DNA比值与PRL含量呈正相关。当PRL维持高水平时,血液中P/E_2比值下降,对泌乳启动有促进作用。用同样激素处理屡配不孕的6头黑白花奶牛,剂量是山羊的20%(单位体重计),亦获得良好的乳腺发育及泌乳效应,血液中的激素变化规律与山羊基本一致。在本实验的剂量条件下,未曾观察到利血平对土种山羊和黑白花奶牛的PRL和乳计分泌有促进作用。
The changes of 17β-estardiol (E_2) ,progesterone (P) and prolactin (PRL)concentration in peripheral blood of seven indigenous virgin goats and six dairy cows were studied. The goats were given 0.5 mg 17β-estradoil and 12.5 mg progesterone per kg body weight by subcutaneous injection for 7 days. 17β-estradiol, progesterone and prolaction concentration in serum were determined by RIA. RNA and DNA concentration in mammary gland samples were also estimated. During the course of artificial induction, the colostrum-like secretion of mammary gland was obtained about day 15 and milk secretion appeared about day 20-21, the ratio of RNA / DNA varied along with the outer appearance of mammary gland development. The positive correlation between RNA / DNA and prolactin concentration was found. When PRL concentration was maintained at high level ratio of P / E_2was decresed, and this change promoted the initiation of lactation. Six infertile dairy cows were also treated with 17β-estradiol and P, the dose of which was lower about five times that of treated goats by per kg body weight. The variation of concentration of three hormones in peripheral blood of cows generally was as same as that of goats. In our experiments, the effect of reserpine on increasing PRL concentration in blood and promoting lactation was not observed in goats and cows.
出处
《中国应用生理学杂志》
CAS
CSCD
1989年第2期167-167,共1页
Chinese Journal of Applied Physiology
关键词
雌二醇
孕酮
催乳素
泌乳
induction of lactation
17β-estradiol
progesterone
prolactin
