In vitro studies on the human renal calices.

Smooth muscle preparations taken from the minor calices of human kidneys were investigated by an isolated tissue technique. The existence of alpha-adrenoceptor and muscarinic receptor sites were demonstrated and it was shown that stimulation with the appropriate agonist resulted in an excitatory response. No evidence could be found to support the presence of beta-adrenoceptors in such tissues. The results of transmural electrical stimulation of similar preparations were highly suggestive of an effective innervation of the alpha-adrenoceptors.