Studies on sympathetic mechanisms in isolated intestinal and vas deferens preparations.

The effects of various drugs which block sympathetic nerves have been studied in Finkleman preparations of rabbit and cat ileum. Contractile responses could be produced in many cases after the normal inhibitory responses to periarterial nerve stimulation had been blocked. In almost all cases this contractile response was abolished by ganglion-blocking drugs. The normal rabbit ileum Finkleman preparation was found to behave differently towards bretylium than do preparations taken from animals treated with reserpine. The block of the guinea-pig isolated hypogastric vas deferens preparation caused by hemicholinium HC-3 was found to be reversed in the presence of noradrenaline, histamine, or 5-hydroxytryptamine, as was the block caused by guanethidine and bretylium. The results are discussed in relation to the Burn-Rand theory of sympathetic nerve mechanism.