大鼠中枢5-HT1A受体的结合容量与高血压

目的:探讨5-HT1A受体结合容量改变对高血压发病的影响.方法:通过放射性配体与受体结合实验,探讨不同周龄自发性高血压大鼠(SHR)和对照组Wistar-Kyoto (WKY)大鼠在脑区不同部位5-HT1A受体的结合特征.结果:SHR不同脑区脑组织膜的Bmax随着大鼠周龄的增加而增大,且有显著差异;WKY鼠差异不明显.相同脑区不同周龄SHR的Bmax均大于WKY大鼠,且随着周龄的增加血压呈上升趋势,其5-HT1A受体的Bmax与血压成正比,WKY无此现象.4～5周龄的SHR为高血压未形成期,10～12及以上周龄的SHR处于高血压的形成期.结论:当血压发生变化时,中枢5-HT1A受体结合容量发生继发性改变.不同脑区中枢5-HT1A受体结合容量可能与高血压疾病的发生相关.

Binding capacity of 5-HT1A receptor in central nervous system and hypertension in rats

Objective: To study the relationship between the 5 HT 1A receptor specific binding in central nervous system(CNS) and hypertensive stage in rats. Methods: The specific binding of 8 OH DPAT to 5 HT 1A receptor in related sites was investigated in the membrane preparation of several brain regions. Results:Significant differences in the B max and K d were observed in the membrane preparation of medulla oblongata and hypothalamus. WKY 8 OH DPAT binding site were significantly increased compared with that of SHR with the development of hypertension. K d of 4 5 weeks,10 12 weeks,20 22 weeks and >40 weeks old SHR did not differ from that in slices of age matched WKY. B max was increased in the same brain region of SHR when compared to WKY. That rats of 4 5 weeks were in prehypertensive stage;rats of 10 12 weeks and above were at the stage of establishing hypertensive stage. Conclusion: The difference between SHR and normotensive rats in 5 HT 1A receptor binding in various brain regions may be related to the development of hypertension. When blood pressure changes,binding capacity of 5 HT 1A receptor in CNS changes accordingly.