Chakraborty S
Department of Zoology, University of Calcutta, India.
Gen Comp Endocrinol. 1995 Aug;99(2):185-91. doi: 10.1006/gcen.1995.1100.
Plasma levels of prolactin and luteinizing hormone have been examined in intact and pinealectomized European starling (Sturnus vulgaris) during termination and onset of photorefractoriness. Photorefractory starlings exposed to long (18L:6D) daily photoperiods for 10 weeks were pinealectomized. One week after pinealectomy these birds, along with the intact and sham-operated birds, were transferred to short (8L:16D) daily photoperiods. After 10 weeks on short day lengths the daily photoperiod was switched to long (18L:6D) and the birds remained on this regime for a further 10 weeks. Plasma prolactin and luteinizing hormone were determined prior to pinealectomy and then weekly throughout the experiment. Molt scores were also recorded. Profiles of both the hormones and the molt pattern were similar in pinealectomized, sham-operated, and intact control starlings. In European starlings the pineal gland does not seem to exert significant effects on the photoinduced rise in plasma prolactin and luteinizing hormone seen in photosensitive birds. It is also suggested that pinealectomy has no significant effect on the dissipation and onset of photorefractoriness assessed from plasma luteinizing hormone secretion in this bird.
在欧洲椋鸟（Sturnus vulgaris）进入和解除光不应期期间，对完整和松果体切除的欧洲椋鸟的血浆催乳素和促黄体生成素水平进行了检测。将暴露于每天18小时光照：6小时黑暗的长日照10周的光不应期椋鸟进行松果体切除。松果体切除术后一周，这些鸟与完整和假手术的鸟一起被转移到每天8小时光照：16小时黑暗的短日照环境。在短日照环境下饲养10周后，每日光照周期改为长日照（18L:6D），并让这些鸟在该光照制度下再饲养10周。在松果体切除术前以及整个实验过程中每周测定血浆催乳素和促黄体生成素。同时记录换羽评分。松果体切除、假手术和完整对照的椋鸟的激素水平和换羽模式相似。在欧洲椋鸟中，松果体似乎对光敏鸟类血浆催乳素和促黄体生成素的光诱导升高没有显著影响。研究还表明，根据这种鸟类血浆促黄体生成素分泌评估，松果体切除对光不应期的解除和开始没有显著影响。
