家兔侧脑室灌注EGTA后发热效应及脑脊液cAMP,PGE_2含量变化的观察

Studies on the mechanism of EGTA-induced fever and changes of cAMP and PGE levels in c. s. f. after EGTA intraventricular perfusion in rabbits

现已证明在多种致热原引起的发热中,脑内的环磷酸腺苷(cAMP)和前列腺素E(PGE)水平均升高。我们还知道当Na^+/Ca^(++)比值改变时,体温也随之变化。这提示cAMP、PGE和Na^+/Ca^(++)比值是发热反应的主要中枢介质。但是,它们三者之间存在何种相互关系?它们在发热机制中各占什么地位?目前尚未见报道。这些同题的正确解决必定非常有助于发热机制的进一步研究。本文通过给家兔侧脑室灌注EGTA或CaCl_2改变Na^+/Ca^(++)比值,然后观察体温反应及脑脊液cAMP、PGE_2水平。我们发现cAMP与体温反应间存在正相关关系(r=0.9913,P<0.05),与PGE_2之间无明显相关(P>0.05)。EGTA能引起体温升高,但是,预先灌注CaCl_2能抑制EGTA性发热。

The levels of cyclic AMP and prostaglandin E (PGE) in the brain are raised in many kinds of fever induced by various pyrogens, we also know when the ratio of Na^+/Ca^(++) is changed in the brain, the body temperature changes. So it is suggested that cAMP, PGE and the ratio of Na^+/Ca^(++) are major central mediums in febril response. It is not clear what relationship is among these three factors and what are their roles respectively in the fever mechanism? It must be very helpful for the development of fever study if we can have them correctly answered. In this paper, we change the Na^+/Ca^(++) ratio by intraventricular perfusion with EGTA or CaCl_2, and observed the temperature response, levels of cAMP and PGE_2 in c.s.f. It is found that there was a positive correlation between cAMP and the body temperature(r=0.9913, P<0.05). But it wasn't in PGE_2(P>0.05). EGTA can raise body temperature. But CaCl_2 pretreatmentd could lower the EGTA fever.