Expression Of NOS And ER Double-labeled Neurons In The Rat's Hypothalamus

Objective:Investigating distribution and coexistence of estrogen receptor(ER) and nitric oxide synthase (NOS) is to provide morphologic proof of inherent relationship between nitric oxide (NO) and estrogen .Methods:Slices of 30 SD-rats'hypothalamus were collected, the morphology and distrbution of NOS positive neurons,ER-IR neurons and NOS/ER double-labeled neurons in the hypothalamus were observed by using NADPH-d histochemical technique combined with immunohistochemical method. The number of NOS positive neurons,ER-IR neurons and NOS/ER double-labeled neurons and proportion of double-labeled neurons were accounted in image analysis system. Results :⑴NOS positive neurons were mainly located in the hypothalamic paraventricular nucleus, supraoptic nucleus, periventricular nucleus and lateral hypothalamic area of female rats.⑵The ER-IR neurons mostly existed in the supraoptic nucleus, paraventricular nucleus and lateral hypothalamic area. The expression of ER was not more extensive than NOS in the hypothalamus.In the periventricular nucleus and cerebral cortex, ER-IR neurons were scattered.⑶NOS/ER double-labeled neurons were detected in the paraventricular nucleus, supraoptic nucleus, periventricular nucleus and lateral hypothalamic area. A small quantity of double-labeled positive neurons were observed in other areas of the brain.The double-labeled neurons were mostly distributed in the medial dorsal and lateral dorsal of supraoptic nucleus and in the medial parvicellular, ventral zone. The double-labeled neurons were also detected in lateral hypothalamic area. In the periventricular nucleus, the double-labeled neurons were occasionally detected. Conclusion:⑴There are NOS/ER positive neurons in the hypothalamic paraventricular nucleus, supraoptic nucleus, periventricular nucleus and lateral hypothalamic area.⑵The double-labeled neurons were mostly distributed in the medial dorsal and lateral dorsal of supraoptic nucleus and in the medial parvicellular, ventral zone. They were extensive slightly,but scattered in lateral hypothalamic area, sporadic in the periventricular nucleus.