[Analysis of the modulating effect of catecholamines on electrogenesis in an isolated mechanoreceptor]

Superfusion of the isolated Pacinian corpuscles from cat mesenterium with solutions containing dibutyril-cAMP or theophylline caused an increase in spike activity and a decrease in receptor potential amplitude and firing potential threshold. An opposite effect was observed after catecholamine application. It was suggested that the effect of catecholamines on the Pacinian corpuscles is accompanied by a decrease in the cAMP level in a sensory nerve terminal. Norepinephrine decreased the adenylate cyclase activity and activated Na+, K+-ATPase in homogenates of Pacinian corpuscles. The effect of norepinephrine on Na+, K+-ATPase could be eliminated by phentolamine and was not sensitive to propranolol. A possible participation of alpha-adrenoreceptors in modulating catecholamine effect on electrical activity of the Pacinian corpuscles is discussed.