[Effects of stimulation of arcuate nucleus on intragastric pressure and peripheral pathway analysis in rats]

The effect of electrical stimulation of arcuate nucleus (ARC) on intragastric pressure (IGP) was examined on 68 Wistar rats anaesthetized with urethan. The results were as follows: (1) Stimulation of ARC could induce an obvious decrease of IGP. (2) This effect was not blocked by atropine but partially by vagotomy. (3) Extirpation of celiac neural plexus or intramuscular injection of phentolamine could obviously reduce the suppression of IGP induced by ARC stimulation, but intramuscular injection of propranolol had no such effect. (4) After vagotomy plus extirpation of celiac neural plexus, IGP could still be made a decrease by stimulating ARC. In view of the present investigation, it is suggested that (1) Both sympathetic nerve and vagus are involved in the reduction of IGP induced by ARC stimulation, the former and the latter routes being respectively mediated by alpha-adrenoceptor and non-cholinergic, non-adrenergic fibres. (2) Humoral factors may be also involved in this effect of ARC stimulation.