The effect of hexamethonium on gastric acid secretion in the conscious rat

Abstract

Evidence against a role for histamine in pentagastrin-stimulated acid secretion has been obtained previously using hexamethonium in gastric fistula rats. This possibility has been re-examined in conscious rats provided with gastric fistulae or Heidenhain pouches. Hexamethonium (20 mg/kg s.c.) inhibited basal acid secretion and acid secretion stimulated by histamine and pentagastrin in gastric fistula rats. The same dose of hexamethonium failed to produce a significant inhibition of acid secretion stimulated by bethanechol, pentagastrin or histamine in the presence of a low dose of bethanechol in Heidenhain pouch rats. These results provide no evidence to oppose the view that pentagastrin-stimulated acid secretion in the rat is mediated at least in part through the mobilization of gastric mucosal histamine. The inhibition of secretagogue induced acid secretion in the gastric fistula rat is mainly the result of a reduction in the basal acid output.

The effect of CCKB/gastrin antagonists on stimulated gastric acid secretion in the anaesthetized rat

“…Earlier studies have demonstrated the ability of gastrin or pentagastrin to initiate histamine release from gastric mucosa (Ekblad, 1985) and mast cells (Tharp et al, 1984), thus confirming the view that part of the gastric acid secretion effect of gastrin is through histamine. In the rat, histamine is stored in endocrine-like cells (Hakanson et al, 1976) and gastrin stimulates the formation of histamine by inducing the activity of histidine decarboxylase (Kahlson & Rosengren, 1968;Hakanson & Leidberg, 1970) and diminishes gastric mucosal histamine (Haverback et al, 1964;Bunce & Parsons, 1977;Main & Pearce, 1982).…”

Lack of cholinergic innervation in gastric mucosa does not affect gastrin secretion or basal acid output in neurturin receptor GFRα2 deficient mice

“…The ganglion blocker hexamethonium is known to reduce basal acid secretion similarly to surgical vagotomy (Kay & Smith, 1951; Bunce & Parsons, 1977). Hexamethonium (20 mg kg −1 , s.c. ) reduced basal acid output in wild‐type mice by ∼70% compared with saline treatment ( P < 0.001).…”

The effect of cystamine on gastric secretion in the rat

“…Since the high basal secretion found in the conscious fistula rat can complicate interpretation of the action of secreta- gogues and secretory inhibitors [5], further studies were performed in the anaesthetized, vagotomized rat in which basal secretion is very low. Cystamine given by rapid intravenous injection stimulated gastric acid secretion in this preparation.…”

“…The surgical preparation and post-operative care of gastric fistula rats has been described previously [5]. Female rats of the Wistar strain weighing approximately 200-250 g were used.…”