摘要
对8头种公羊在整个秋季配种季节中血清催乳素含量的变化及与睾酮和促黄体素(LH)水平之间的关系进行了研究。结果表明公羊催乳素水平并不是象文献报道的在秋季配种季节开始前下降,而是在配种季节开始有一个高峰(从104ng到150ng/ml)。该峰持续一个月才开始下降。在催乳素峰同时睾酮水平也呈现峰值,而此时血清中LH则无变化。在配种季节的第一个配种期(8月,实验场地规定)和非交配期(9月)分别给公绵羊注射催乳素(1.5mg/头)。连续采血测定血清中各激素水平的结果表明在这两段时间注射催乳素2小时后血清中睾酮水平总含量和总平均值显著地高于对照组(第一个配种期时分别为:17.79±2.54对3.85±0.61,P<0.01和2.20±0.66对0.48±0.09,P<0.001;非交配期分别为4.88±1.06对1.13±0.24,P<0.05和1.22±0.31对0.28±0.04,P<0.025),而且此时睾酮水平与LH水平无关,因为此时血清中LH水平无明显变化。从上述结果看出催乳素在体内的骤然增加可以促使公绵羊血清中睾酮水平升高,而且睾酮的这种增加并不是通过催乳素促使LH分泌引起的。推测在季节性生殖的公绵羊由性活动静止到活跃的这一特殊时间内,催乳素的升高是促进睾酮分泌的一个重要因子。
The variation of serum prolactin ( PRL ) , LH and testosterone levels of 8 rams was monitored through all breeding season and the relationship among these hormones was studied. A' connula was placed into ram's jugular vein and PRL was injected (1.5mg/ram) at the first mating period ( August ) and non-mating period (September) respectively. The serum was collected continuously at a interval of 30 minutes. The result showed that serum PRL level did not decline with the shortening of the light period in Autumn breeding season as reported by Barenton et al(1980). But, it had an elevated value at the begining of the breed- ing season (from 104ng to 150ng/ml ) . The level remained for one month and then declined. At the same time of PRL high level,a parallel increase in the testosterone level was observed, while LH remained unchanged significantly. In both cases of PRL administration, a increase level of testosterone was detected, especially of testosterone secretion were significantly greater than that of control group ( at the first mating period: 17.79±2.54 to 3.85 ± 0.61 p<0.01 and 2.20±0.66 to 0.48 ±0.09 p<0.001; at non-mating period: 4.88±1.06 to 1.13±0.24 p<0.05 and 1.22±0.31 to 0.28±0.04 p<0.025 ) . The increase of testosterone level was not related to the LH level, as the ram's serum LH did not change significantly during this period. This indicates that increase of the serum testosterone level after PRL administration was not due to a stimulation of LH secretion by PRL. These results suggest that a sharp increase of PRL in the serum of rams, at the special period from seasonal sexual inactivity to activity, might be an important and characteristic factor in promoting testosterone secretion. The direct effection of PRL on testosterone secretion should be furtherly confirmed by the Leydig cells culture in vitro.
出处
《畜牧兽医学报》
CAS
CSCD
北大核心
1991年第1期4-8,共5页
ACTA VETERINARIA ET ZOOTECHNICA SINICA
关键词
公绵羊
催乳素
促黄体激素
睾酮
羊
Ram's reproduction , Prolactin , Luteinizing hormone, Testosterone
