次声对脑组织血栓素A_2、前列环素代谢的影响

目的　探讨次声作用后脑皮层组织血栓素A2 (TXA2 )、前列环素 (PGI2 )代谢改变及及代谢性谷氨酸受体拮抗剂MCPG的作用。方法　 40只SD大鼠随机分为正常对照、次声作用 1次、7次、14次及代谢性谷氨酸受体拮抗剂MCPG治疗 5组。采用第四军医大学研制的次声压力仓。用 8Hz、12 0dB的次声按规定次数 ,每次作用 2h。采用蛋白定量和放免法行脑TXA2 、PGI2 稳定代谢产物血栓素B2 (TXB2 )及 6 酮 PGF1α( 6 酮 )含量测定。结果　 7次与 14次组 ,TXB2 含量有显著意义升高 (P <0 .0 1) ,6 酮含量明显降低 (P <0 .0 1)。TXA2 /PGI2 值呈递增趋势 ;治疗组 ,TXB2 及 6 酮含量与TXA2 /PGI2 值恢复致正常水平。结论　次声可以通过引起脑TXA2 、PGI2 代谢改变造成脑损害 ,是次声导致脑损害的关键因素之一。MCPG可能通过影响脑TXA2 、PGI2 代谢改变而起脑保护作用。

Change and significance of TXA_2 and PGI_2 metabolism after infrasonic damage

Objective To study the change and significance of the TXA 2 and PGI 2 metabolism and the effects of metabotropic glutamate receptor mGluR antagonist MCPG after infrasonic damage to the rats so as to probe into the mechanism of infrasonic biologic effects.Methods 40 SD rats were randomizied into five groups including control, infrasonic damage 1 time, 7 time, 14 time and MCPG treatment. 8 Hz,120 dB infrasound was applied to infrasonic groups for 2 h once according to the planned times. Immunoradioassay was used for the examination of brain TXB 2 and 6 keto PGF1a(metabolites of TXA 2 and PGI 2) contents.Results There were no changes in TXB 2 and 6 keto PGF1a levels in 1 time group while TXB 2 level elevated significantly and 6 keto PGF1a level decreased greatly in 7 and 14 time group with an augmentation of TXA 2/PGI 2 value.In treatment group both TXB 2 and PGI 2 levels resumed normal.Conclusion The augmentation of TXA 2/PGI 2 value in 7 and 14 time group suggests that an imbalance in TXA 2 PGI 2 production contributes to the trumatic secondary proceses,including ischemia and edema. In the same degree, the extent of TXA 2 and PGI 2 metabolism disturbance is closely related to the times of infrasounic injury. And it is hypothesed that mGluR antogonist may exert its protective properties through increasing PGI 2 production in injured brain by improving blood supply to injured blood vessels.