大鼠LP和ET发热时不同脑区β－EN含量变化及其作用机理的探讨

β-endorphin content changes in different brain regions and its mechanisms of action during LP and ET fever in rat zhang

实用昆明大鼠经静脉注射家兔白细胞致热原（ＬＰ）或内毒素（ＥＴ），分别复制发热模型。用放射免疫法分别测定了ＬＰ和ＥＴ发热动物中枢不同脑区β－内啡肽（β－ｅｎｄｏｒｐｈｉｎ，β－ＥＮ）的含量变化。结果表明（１）大鼠ＬＰ双相热各时相其下丘脑组织β－ＥＮ含量均明显高于对照组（ｐ＜０．０１），且发热间歇期和体温恢复期β－ＥＮ含量高于发热时相（Ｐ＜０．０５）。中脑β－ＥＮ含量在发热第一时相高于对照组。皮质β－ＥＮ含量无显著变化。（２）大鼠ＥＴ发热高峰期下丘脑组织β－ＥＮ含量也明显高于对照组。中脑区β－ＥＮ含量无显著变化。作者认为，大鼠ＬＰ和ＥＴ发热时中枢内，特别是下丘脑内β－ＥＮ含量升高与ＬＰ和ＥＴ的致热作用有关。并推测β－ＥＮ含量升高变化可能在限制发热过程中有一定作用。

Leucocyte pyrogen(LP,prepared from rabbit white blood cell)and endotoxin(ET)were injected intravenously to produce fever in rat.Change of β-endorphin(β-EN)content in different brain regions was observed by RIA,The results showed:(1)The con-tent of β-EN in hypothalamus during fever induced by LP were much higher than thatof control group in all phase of fever,especialy in the interal between 1st and 2nd phasefever as well as recovery phase of fever(P<0.01 ).The β-EN content in midbrain wasnot markedly changed during biphasic fever except that it increased in the lst phase.Infever group β-EN lvel in cortex during biphasic fever was not distinguished from thatof the control group.(2)The β-EN content in hypothalamus in the peak phase of feverincreased as compared with the control group (P< 0.05),but in the midbrain these was notmuch changed.It was suggested that the change of β-EN in different brain regionsduring fever induced by LP and ET were related to the pyrogenic effect of LP and ET,and that the increase of β-EN in fever phase may play some role in limiting fever.