In vitro studies on smooth muscle of the human renal pelvis.

Isolated segments of human renal pelvis were studied by an isometric technique. Increases in tension following the addition of adrenaline, noradrenaline and phenylephrine were shown to be mediated via alpha-adrenoceptors. Similar responses to acetylcholine were demonstrated to be due to muscarinic receptor stimulation. Specimens responded to transmural electrical stimulation only when the pulse width was greater than 4 msec, and such responses were unaffected by pretreatment with tetrodotoxin, phentolamine and atropine. These experiments suggest that there is no effective innervation of the receptor sites identified, and hence that renal pelvis motility in vivo is not amenable to regulation by the autonomic nervous system.