摘要
金鱼对LRH-A反应有明显的季节性变化,在早春(2月)生殖季节开始前诱导的血清GtH含量最高;在生殖季节过后(5—6月)GtH的释放反应减弱,而在夏季(8月)性腺处于退化状况时,反应很弱或者没有反应。LRH-A注射剂量的高低对血清GtH含量增高的影响并不都很明显,但高剂量(1.0微克/克体重)能诱导较高的血清GtH含量并能维持24小时。经过多次注射高剂量以后,脑垂体GtH含量下降。温度、注射剂量、注射间隔时间都和诱导的血清GtH含量有密切关系。连续9—10天每日注射LRH-A,能刺激性腺退化的金鱼恢复性腺发育,但对性腺已开始发育的金鱼,却抑制或减慢其性腺进一步发育。
The effects of season, temperature, dosage, frequency of injection and interval between injections on the GtH release-response to LRH-A in goldfish were investigated. The results demonstrated that goldfish have a very dramatic seasonal variation in responsiveness to LRH-A. The highest serum GtH levels induced were just prior to the spawning season in early spring (February.) Following the spring spawning season (May-June), the GtH release-response was less, and, in the summer (August)when the fish were sexually regressed, there was little or no response. A dose dependence was not always clear in the response, but high dose (1.0 ug/g body weight) usually induced the highest levels and had a persistent effect for 24 hours. The pituitary GtH level was significantly lower after a series of injections of high dose. There is a close relationship between the level of serum GtH induced, and temperature, the dosage of LRH-A injected, the interval between injections.Daily injections of LRH-A for up to 9—10 days can stimulate onset of gonadal recrudes.cence in sexually regressed goldfish; however, it may slow down or block gonadal recrudescence in goldfish that have commenced development.
