Influence of microinjection of scopolamine into various brain areas on pressor effect of electroacupuncture in nitropressideinduced hypotensive dogs
Xiao Yongfu, Li Peng
Department of Physiology, Shanghai First Medical College. Shanghai, China
Abstract
In 14 conscious dogs implanted with stainless steel cannulae, the effect of microinjection of the cholinergic agonist or antagonist into various brain areas on the pressor effect of electroacupuncture (EA) was investigated. Following microinjection of scopolamine (20 #mu#g dissolved in 2 #mu#l isotonic saline) into the midbrain central gray (CG), the midbrain reticular formation (RF) and the ventromedial hypothalamus (VMH) in hypotensive dogs induced by infusion of sodium nitroprusside (NP), the pressor effect of EA was blocked. On the other hand, acetylcholine (ACh, 200 #mu#g dissolved in 2 #mu#l isotonic saline) microinjected into those areas elicited a pressor effect (P<0.01), which lasted about 10 min. It is suggested that the pressor effect of EA during NP hypotension was mediated by the activation of the muscarinic receptors in CG, RF and VMH.
Key words: Electroacupuncture;Nitroprusside;Scopolamine;Midbrain central gray;Ventromedial hypothalamus
Received: Accepted:
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Citing This Article:
Xiao Yongfu, Li Peng. Influence of microinjection of scopolamine into various brain areas on pressor effect of electroacupuncture in nitropressideinduced hypotensive dogs. Acta Physiol Sin 1985; 37 (1): (in Chinese with English abstract).