脑室注射组胺抑制大鼠胃酸分泌的外周机制

PERIPHERAL MECHANISM OF INHIBITORY EFFECT OF CENTRALLY ADMINISTRATED HISTAMINE 0N GASTRIC ACID SECERTION

本文分析了第三脑室注射组胺（HA）抑制胃酸分泌效应的外周过程。雄性SD大鼠，摘除双侧肾上腺，用37℃的生理盐水通过恒流泵进行连续胃灌流。用注射器泵静脉每小时给药，观察其对五肽促胃液素（10μg/kg，iv）诱导的胃酸分泌的影响。结果如下：（1）切除双侧膈下迷走神经可阻断HA（1μg，icv）的中枢抑酸效应；（2）预先静脉注射硫酸阿托品［0.05mg／（kg·100min）］可阻断HA的中枢抑酸效应；（3）预先静脉注射生长抑素拮抗剂[2～4μg/（kg·100min）]，可剂量依赖性地拮抗HA的中枢抑酸效应。结果提示：HA的中枢抑酸效应由迷走神经传出，可能通过乙酰胆碱M受体及引起生长抑素释放实现。

The present experiment is undertaken to study the peripheral mechanism of the inhibitory effect of intra third ventricular administration of histamine (HA, icv) on gastric acid secretion. Gastric acid was continuously washed with 37℃ saline by means of a perfusion pump in male adrenalectomized SD rats. Drugs were injected intravenpusly by a syringe pump and their effect on pentagastrin-induced [ 1Og/ (kg' h), iv] gastric acid secretion was measured - The results were as follows: (1 ) The inhibitory effect of HA on gastric acid secretion was abolished by subdiaphragmatic vagotomy. (2) The inhibitory effect of HA on gastric acid secretion could be abolished by pretreatment with atropine [0.05 mg/(kg. 100 min), iv ］. (3) Pretreatment with somatostatin antagonist, cyclo[7-aminoheptanoyl-Phe-D-Trp-Lys- (Bzl) ], [ 2 ～4 g /(kg. 100 min), iv］ could a1so block the inhihitory effect of HA on gastric acid secretion in a dose dependent manner. The above results suggest that the inhibitory effect of centrally administrated HA on gastric acid secretion is mediated by vagi, acetylcholine M receptor and somatostatin.