[Influence of microinjection of scopolamine into various brain areas on pressor effect of electroacupuncture in nitroprusside-induced hypotensive dogs].
摘要
In 14 conscious dogs implanted with stainless steel cannulae,the effect of mi-croinjection of the cholinergic agonist or antagonist into various brain areas on thepressor effect of electroacupuncture(EA)was investigated.Following microin-jection of scopolamine(20 μg dissolved in 2 μl isotonic saline)into the midbraincentral gray(CG),the midbrain reticular formation(RF)and the ventromedialhypothalamus(VMH)in hypotensive dogs induced by infusion of sodium nitro-prusside(NP),the pressor effect of EA was blocked.On the other hand,acetylcholine(ACh,200 μg dissolved in 2 μl isotonic saline)microinjected into those areaselicited a pressor effect(P0.01),which lasted about 10 min.It is suggested thatthe pressor effect of EA during NP hypotension was mediated by the activation ofthe muscarinic receptors in CG,RF and VMH.