Abstract
Distension of the vagally denervated fundic gland area, although by itself a generally ineffective stimulus to acid secretion in this study, will markedly increase the acid secretory response to stimulation by endogenous gastrin, pentagastrin and histamine. Even maximal responses to histamine can be increased, thus demonstrating true potentiation between distension and humoral stimuli. The magnitude of the distension potentiation does not appear to be influenced by the nature of the background stimulus or the background level of secretion. The distension potentiation of the response to histamine is reduced but not abolished by intravenous atropine and hexamethonium. Thus, there appear to be two components to the local distension mechanism. One is cholinergic, the other, atropine-resistant component is possibly non-cholinergic. At least one of these components, possibly the cholinergic, involves a nicotinic synapse in its pathway.