Involvement of thuroid gland on the seasonal breeding of Japanese monkeys

为了研究甲状腺激素在日本猕猴（Macaca fuscata）季节性繁殖中的作用，在12月初、繁殖季节中期对性成熟雌性猕猴（n=6）进行甲状腺切除，或保留甲状腺完整（n=4）。他们被单独安置在室内，每周采集三次血液样本以监测促性腺激素和性腺激素的分泌。所有动物在手术前的繁殖季节排卵。甲状腺切除术导致所有动物的繁殖季节提前终止：甲状腺切除动物的排卵周期在甲状腺切除术后很快终止。去甲状腺动物的血浆催乳素水平明显高于对照组。这些结果表明，甲状腺激素至少通过调节催乳素分泌参与了日本猴季节性繁殖的调节。

To examine the role of thyroid hormones on the seasonal breeding of Japanese monkeys (Macaca fuscata), sexually mature females were thyroidectomized (n=6) in early December, during the mid-breeding season, or they remained thyroid intact (n=4). They were housed indoors individually, and blood samples were collected three times a week to monitor gonadotropin and gonadal hormone secretions. All animals ovulated during the breeding season before operation. Thyroidectomy resulted in earlier termination of the breeding season in all animals : ovulatory cycles of thyroidectomized animals were terminated soon after thyroidectomy. Thyroidectomized animals exhibited significantly higher levels of plasma prolactin than those of controls. These results suggest that thyroid hormones are involved in the regulation of the seasonal breeding of Japanese monkeys at least by mediating the modification of prolactin secretion.