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目地:ANP和ATⅡ在内环境的稳定中有重要意义,为了观察＋Gz作用对血浆和丘脑组织中ANP及ATⅡ含量的影响,对33只Wistar大鼠进行了不同载荷条件下的离心机实验.方法:33只大鼠随机分为三组,每组11只.＋1Gz暴露为对照组,＋6Gz、＋10Gz为实验组.每组＋Gz作用的峰值时间为5min。血浆和丘脑组织中ANP及ATⅡ均用放射免疫法测定.结果:①+Gz暴露可引起血浆和丘脑ANP增多,＋Gz越高,增多越明显.②＋6Gz暴露后,血浆ATⅡ升高不明显,与血浆ANP相比,有明显滞后现象.至＋10Gz时,血浆ATⅡ含量才开始升高.③＋Gz作用对丘脑组织中的ATⅡ含量影响不明显.讨论:＋Gz作用后,血浆和丘脑组织中ANP含量均明显升高,血浆ATⅡ改变相对滞后,丘脑ATⅡ改变不明显,结果使ANP与ATⅡ比值增大.＋Gz作用后丘脑组织中ANP合成增多的原因还不清楚,用颅内缺血的机理不好解释.弄清ANP上升的原因对阐明G-LOC发生的确切机理有一定帮助,对传统G-LOC发生的缺血学说可能是一次挑战.由于ANP有强大的利尿、排钠和扩血管作用,以及抑制肾素分泌和拮抗ATⅡ的缩血管效应,因此,对周围和中枢循环的血流动力学将产生不利影响,在G-LOC和脑水肿的发生机理中可能有重要意义.
In order to observe the effect of + Gz on the content of ANP and ATⅡ in plasma and thalamic tissues, 33 Wistar rats were centrifuged under different loading conditions.Methods : 33 rats were randomly divided into three groups with 11 rats in each group, + 1Gz exposure as the control group, +6 Gz, +10 Gz as the experimental group, and the peak time of + Gz for each group was 5 minutes. The levels of ANP and ATⅡ were measured by radioimmunoassay in plasma and thalamus.Results: ①Gz exposure increased plasma ANP and increased the level of + Gz in the plasma and thalamus.② After AT + 6Gz exposure, plasma ATⅡ level did not increase significantly ANP, there was obvious hysteresis.At + 10Gz, plasma ATⅡcontent began to rise.③The effect of + Gz on the content of ATⅡin the thalamus was not obvious.Conclusion: After + Gz, the content of ANP in plasma and thalamus were significantly increased High, plasma AT Ⅱ changes relative lag, AT Ⅱ insignificant change in the thalamus, the results of ANP and AT Ⅱ ratio increased. + Gz role in the synthesis of thalami ANP synthesis is unclear, with the mechanism of intracranial ischemia is not good. The reason why the rise of ANP is clear in elucidation of the exact mechanism of G-LOC may be a challenge to the traditional ischemic theory of G-LOC.As ANP has a strong diuretic, sodium and vasodilatory effects and inhibit renal Secrete and antagonize the vasoconstrictive effects of AT II and therefore have an adverse effect on the hemodynamics of the peripheral and central circulation and may be of importance in the pathogenesis of G-LOC and brain edema.