摘要
多年使用LRH-A催产的经验说明,不同鱼类对LRH-A的敏感性不同。为探索催产条件的规律,我们曾测定池塘中能自然产卵的鲤和不能自然产卵的草鱼、鲢产卵季节血清促性晚激素(sGTH)的日周期变化。本文则观察和比较心脏灌注LRH-A后1小时和24小时之内sGTH的变化。 三种鱼在灌注LRH-A后5分钟和5—6小时出现sGTH高峰,说明LRH-A对GTH的释放有立即的和迟缓的二种作用。不成熟的鲢也有“5分钟”的高峰,但未见5—6小时的峰。以LRH-A催产后23天的鲢对灌注LRH-A尤为敏感,能刺激sGTH的大量释放。经解剖这些鱼卵巢已发育到Ⅳ。是否在适当时间、温度进行当年第二次催产是值得试验和可能对生产有重要意义的课题。 水温急剧下降的情况下灌注LRH-A,sGTH的高峰出现推迟,可以解释LRH-A催产效应时间增长的原因。
On the basis of species discrepancies of responsiveness to LRH--A, serum gonado-tropin (sGTH) levels of the mature female carps and immature female silver carpwere compared after cardiac injections of LRH-A at two different timos of a day.Fish sera were sampled at intervals either within 1 hour or during a 24--hour period.The sGTH concentration was measured by radioimmunoassay. In all cases, dealingwith the mature fish held under 18--20℃ two distinguished peaks were observed,one within 5 minutes and the other 5--6 hours later. The second peak was notdetectable in immature fish. This may signify that the second surge of GTH was moreimportant than the first in inducing spawning. When carp was subjected to lowertemperatures (11-13.5℃), the occurrence of the peaks was much delayed, which is inaccordance with the fact that when water temperature drops down beyond optimum,the response to the analogue is prolonged or even suppressed as has been found in farmpractice. When silver carps receiving LRH-A 23 days after the first ovulation which wasinduced by the same hormone analogue, the sGTH pattern was similar but higher in magnitude. Anatomical examination showed that ovaries had significantly proceededto the IV stage of maturation. though the GSI values were lower than that prior to thefirst ovulation. The long-term effect of LRH--A in terms of acceleration of ovarianrecrudescence in the postspawning phase of the reproductive cycle was apparent.
出处
《水产学报》
CAS
1981年第2期103-109,共7页
Journal of Fisheries of China
