新生大鼠下丘脑CRF和AVP神经元对急性低氧的应答

目的:观察肾上腺摘除新生大鼠下丘脑促肾上腺皮质激素释放激素(CRF)和精氨酸加压素(AVP)神经元对急性低氧的应答.方法:在低压氧舱中模拟高海拔低氧,用放免法测定AVP和CRP含量.结果:新生大鼠暴露于急性低氧环境下(模拟5 000 m和7 000 m海拔高度,24 h),其下丘脑CRP在3 d和7 d龄大鼠中无明显变化,但14d、21 d和28 d时低于对照;下丘脑AVP在3 d大鼠中亦无变化,但14 d时低于对照,7 d、21 d及28 d时高于对照.两者对低氧的应答模式随日龄而变化.摘除肾上腺后,14 d、21 d及28 d大鼠下丘脑CRF和AVP含量均显著低于同龄完整大鼠,此时暴露于急性低氧环境下,CRF和AVP无进一步的变化.结论:摘除肾上腺抑制下丘脑CRF和AVP的发育,影响它们对低氧应激的正常应答.

The response of hypothalamic CRF and AVP neurons of neonatal rats to simulated acute hypoxia

Aim: To investigate the response of hypothalamic corticotropin releasing factor(CRF) and arginine vasopressin(AVP) of adrenalectomized neonatal rats to hypoxia.Methods: The hypoxia was simulated in hypobaric cabin.The amount of arginine vasopressin(AVP) and corticotropin releasing factor(CRF) was assayed by RIA method.Results: When neonatal rats exposed to acute hypoxia(simulated altitude of 5 000 m and 7 000 m,24 h),their hypothalamic CRF was not changed in 3 d and 7 d rots,lower than control in 14 d,21 d and 28 d rats,while hypothalamic AVP had no change in 3 d rats,was lower than control in 14 d and higher in 7 d,21 d and 28 d rats.The responsive pattern of those two neuropeptides to acute hypoxia changed with the growth of rats.Adrenalectomy reduced the amount of hypothalamic CRF and AVP in 14 d,21 d and 28 d rats,except AVP in 28 d rats.When adrenalectomized neonates exposed to hypoxia,there was no further change in CRF and AVE,means adrenalectomy not only removed the negative regulation of corticosteroid on CRF and AVE,but also inhibited the normal development of CRF and AVP neurons and thus,their responsive ability to hypoxia.