Shi Z D, Barrell G K
Animal and Veterinary Sciences Group, Lincoln University, New Zealand.
J Reprod Fertil. 1992 Jan;94(1):251-9. doi: 10.1530/jrf.0.0940251.
The effect of thyroid function on regulation of seasonal reproduction was investigated in three red deer stags thyroidectomized (THX) in summer (January 1988) in comparison with five thyroid-intact controls. Responses of luteinizing hormone (LH) and testosterone to a bolus injection of 10 micrograms gonadotrophin-releasing hormone (GnRH) were tested in July, October, December, February and April. Blood samples were collected at weekly intervals from December 1987 to June 1989 for measurement of testosterone, triiodothyronine (T3) and prolactin concentrations. Testis diameters were measured every 2 weeks. In October 1988 (spring), plasma LH concentrations of control stags were less responsive (P less than 0.01) to stimulation by GnRH than those of THX stags; plasma testosterone concentrations and testis diameters were low and there was no increase in plasma testosterone concentrations after injection of GnRH in control stags during October or December (spring, early-summer). In contrast, THX stags maintained a testosterone response (P less than 0.01) in these 2 months and did not exhibit any signs of a seasonal lack of reproductive activity at this time of year. Control stags cast antlers in spring whereas THX stags maintained hard antlers throughout the study. Concentrations of plasma T3 were not detected in THX stags from June 1988 onwards, but exhibited a seasonal pattern in control stags, with low concentrations during autumn and winter (April to July) and high concentrations in spring and summer (August to February). There was no effect of thyroidectomy on the seasonal pattern of prolactin secretion.(ABSTRACT TRUNCATED AT 250 WORDS)
研究了甲状腺功能对季节性繁殖调节的影响，将1988年1月（夏季）进行甲状腺切除（THX）的三只马鹿雄鹿与五只甲状腺功能正常的对照鹿进行比较。于7月、10月、12月、2月和4月测试促黄体生成素（LH）和睾酮对静脉注射10微克促性腺激素释放激素（GnRH）的反应。从1987年12月至1989年6月每周采集血样，测定睾酮、三碘甲状腺原氨酸（T3）和催乳素浓度。每2周测量一次睾丸直径。1988年10月（春季），对照雄鹿的血浆LH浓度对GnRH刺激的反应性低于THX雄鹿（P<0.01）；对照雄鹿的血浆睾酮浓度和睾丸直径较低，且在10月或12月（春季、初夏）注射GnRH后血浆睾酮浓度未升高。相比之下，THX雄鹿在这两个月维持了睾酮反应（P<0.01），且在一年中的这个时候没有表现出任何季节性繁殖活动缺乏的迹象。对照雄鹿在春季脱角，而THX雄鹿在整个研究过程中鹿角坚硬。从1988年6月起，在THX雄鹿中未检测到血浆T3浓度，但对照雄鹿呈现季节性模式，秋季和冬季（4月至7月）浓度较低，春季和夏季（8月至2月）浓度较高。甲状腺切除对催乳素分泌的季节性模式没有影响。（摘要截短于250字）
