下丘脑后核、蓝斑及延髓头端腹外侧加压区间的机能联系

FUNCTIONAL CONNECTIONS AMONG PRESSOR AREAS OF NUCLEUS HYPOTHALAMICUS POSTERIOR,LOCUS COERULEUS AND ROSTRAL VENTROLATERAL

实验用乌拉坦麻醉,箭毒化和人工呼吸的大鼠,将L-谷氨酸钠(Glu)微量注入下丘脑后核(HP)。使血压升高、心率加快,此效应既可被蓝斑内注射阿托品衰减,还可被延髓头端腹外侧区(RVL)内注射阿托品基本阻断。HP内注射酚妥拉明或心得安也能衰减Glu兴奋蓝斑的加压效应。而静脉注射甲基阿托品阻断心迷走神经的作用,对兴奋HP引起的加压、加速心率效应无明显影响。

In urethane-anesthetized, tubocurarine-immobilized and artificially ventilated rats, microinjection ofsodium L-glutamate (Glu) into nucleus hypothalamicus posterior (HP) induced a pressor-tachycardiaresponse. The pressor-tachycardia effect of HP-excitation was reduced by preinjection of atropine intolocus coeruleus (LC) and even completely blocked by atropine-preinjection into rostral ventrolateralmedulla (RVL), which suggests that the cholinergic neurons in HP may act directly and indirectly(via LC) on RVL to exert a pressor function. Injection of phentolamine or propranolol into HP alsodecreased the pressor effect of LC-excitation, showing that HP-RVL is also involved in LC-pressorresponse. Moreover, both pressor and tachycardia effects of HP-excitation remained nearly unchangedafter blockade of cardiac vagus by intravenous injection of methyl atropine, indicating that the pressor-tachycardia response to HP-excitation is mainly due to activation of the sympathetic system.