摘除松果腺对大鼠视交叉上核节律性的影响

成年Ｗｉｓｔａｒ雄性大鼠２０只，实验组１０只，行松果腺摘除术；对照组１０只。术后３０ｄ将实验组、对照组动物各半数在０９：００～１０：００和１６：００～１７：００分别处死。用免疫组化ＡＢＣ法显示视交叉上核内含ＶＩＰ的神经元；微机图像分析仪上测量其光镜下的切面面积及平均免疫反应强度。结果：（１）对照组不同时间处死的动物ＶＩＰ样神经元切面面积０９：００～１０：００大于１６：００～１７：００，呈节律性变化。（２）摘除松果腺后各时间组间ＶＩＰ样神经元切面面积的差异无显著性，提示实验组动物视交叉上核的ＶＩＰ样神经元功能活动的日周节律已发生改变。（３）对照组和实验组动物的ＶＩＰ样神经元平均免疫反应强度在所测的两个时间中均未见明显差异。

EFFECT OF PINEALECTOMY ON THE SUPRACHIASMATIC NUCLEUS(SCN) OF HYPOTHALAMUS IN RAT── IMMUNOHISTOCHEMICAL QUANTITATIVE STUDY

Suprachiasmatic nucleus (SCN), as an important circadian rhythm oscillator in mammal , is modulated by the pineal gland but the mechanism is unknown. In this study, we explored the effects of pinealectomy on circadian rhythm of SCN to approch the mechanism of circadian rhythm. Twenty Wistar adult male rats were used and divided into experimental group (10 rats ) and control group (10 rats) randomly. The experimental rats received an operation of removing pineal gland were raised for 30 days under normal light-dark cycle (06: 30 ～19: 30 light on). 5 experimental rats and 5 control rats were sacrificed by perfussion with Zamboni solutioin at 09: 00 to 10: 00. Other 5 operated rats and 5 control rats were killed at16: 00 to 17: 00 with same method. Coronal sections (20 μm) were cut on cryostat microtome. VIP-immunoreactive (IR)neurons were shown by immunohistochemical ABC procedures. The general sectional areas and immunoreactive intensity of VIP neurons in SCN were measured with microcomputer image analysis system under light microscope and then treated by statistics (t test). Results: (1) In the control group , the circadian rhythm can be observed. The sectional areas of VIP-IR neurons in SCN was higher at 09: 00～10: 00 than 16:00～ 17: 00, there was significant difference between these twocontral groups. (2) 30 days after pinealectomy, no significant difference was found in rats killed in different time. It indicated that the circadian rhythm of VIP in SCN was changed. These results suggest that pineal gland may participate in regulation of the circadian rhythm of VIP synthesis and secretion in SCN.