大鼠下丘脑生长抑素神经元性差别的观察

本实验用PAP免疫组织化学方法对比观察了雄性与雌性大鼠下丘脑生长抑素(SRIF)神经元胞体、纤维在正常和改变性激素代谢条件下数量或染色程度的差别。结果表明,在室周核(PV)、室旁核(PVN)和视交叉上核(SCN)内,雄性大鼠的阳性细胞和纤维较雌性多。此外,在视前内侧区(MPO)雄性有大量细丝样阳性纤维网络,而雌性只有较稀疏的阳性纤维。切除睾丸后大鼠PV、PVN、SCN阳性细胞和纤维减少,MPO和正中隆起阳性纤维密度降低。而切除卵巢的大鼠在上述区域的阳性胞体和纤维密度增强,当给去性腺的雌、雄性大鼠以同性激素替代后,染色结果接近正常。

OBSERVATION OF SEXUAL DIMORPHISM OF SOMATOSTATIN IMMUNOREACTIVE NEURONS IN THE RAT HYPOTHALAMUS

The distribution and numbers of SRIF-immunoreactive cell bodies and fibers in normal and castrated rats hypothalamus were studied by PAP immunocytochemistry. The results showed that the positive cell bodies and fibers in periventricular nucleus (PV), suprachiasmatic nucleus (SCN) and paraventricular nucleus (PVN) were more numerous in male than in female. Another marked sexual dimorphism was found in medial preoptic area (MPO) which was filled with dense plexus of varicose immunoreactive fibers in male, while there were low density of stained fibers in female. Orchiectomized rats had fewer number of positive neurons in PV, PVN, SCN and arcuate nucleus (ARN), and lower density of fiber in SCN, ARN, MPO and median eminence than the normal rats. On the contrary, in the ovariectomized rats could find more numerous cell bodies and fibers in these areas. When gonadal steroid was given after gonadectomy, the SRIF neurons became similar to the normal.