Lu C C, Tsai S C, Chien E J, Tsai C L, Wang P S
Department of Physiology, School of Life Science, National Yang-Ming University, Taipei, Taiwan, Republic of China.
Metabolism. 2000 Feb;49(2):253-8. doi: 10.1016/s0026-0495(00)91533-6.
The mechanism of hypercalcitoninemia associated with aging was investigated in male rats. To mimic some of the hormonal changes with aging, orchidectomized (Orch) and hyperprolactinemic rats were used to mimic the physiological status of aging. Orch and haloperidol-induced hyperprolactinemic rats aged 3, 8, and 17 months were infused with CaCl2 and then bled from a jugular catheter following the CaCl2 challenge. Rat thyroid gland was incubated with Locke's medium at 37 degrees C for 30 minutes. Compared with 8- and 3-month-old rats, 17-month-old rats exhibited the lowest levels of plasma testosterone and the highest levels of plasma prolactin (PRL) and calcitonin (CT). The release of CT in the thyroid glands in vitro was highest in 17-month-old rats. Orchidectomy decreased rat plasma CT and thyroid CT release in vitro. Hyperprolactinemic rats had higher levels of plasma PRL and CT compared with control animals. The release of thyroid CT in vitro was greater in hyperprolactinemic rats. These results suggest that the hypersecretion of CT in 17-month-old rats may be due in part to hyperprolactinemia.
在雄性大鼠中研究了与衰老相关的高降钙素血症的机制。为模拟衰老过程中的一些激素变化，采用去势（Orch）和高催乳素血症大鼠来模拟衰老的生理状态。对3、8和17月龄的Orch及氟哌啶醇诱导的高催乳素血症大鼠静脉注射氯化钙，然后在氯化钙激发后通过颈静脉导管取血。将大鼠甲状腺在37℃下用洛克氏培养基孵育30分钟。与8月龄和3月龄大鼠相比，17月龄大鼠的血浆睾酮水平最低，血浆催乳素（PRL）和降钙素（CT）水平最高。17月龄大鼠甲状腺体外CT释放最高。去势降低了大鼠血浆CT水平和甲状腺体外CT释放。与对照动物相比，高催乳素血症大鼠的血浆PRL和CT水平更高。高催乳素血症大鼠甲状腺体外CT释放更多。这些结果表明，17月龄大鼠CT分泌过多可能部分归因于高催乳素血症。
