Depressed adrenergic nerve function in tibial arteries of two-kidney one clip Goldblatt hypertensive dogs.

Tibial arteries removed from normotensive dogs and from two-kidney one clip Goldblatt hypertensive dogs, 6-34 days after renal artery constriction, were studied in vitro. Contractions were elicited by transmural stimulation and norepinephrine added to the organ bath. Arteries from the hypertensive dogs exhibited depressed responsiveness to adrenergic nerve stimulation, but not to the lower concentrations of norepinephrine. However, the maximal response to norepinephrine was decreased as has been previously observed in hypertensives' arteries. The results indicate that pre- and postsynaptic factors are involved in the depressed adrenergic responses in the hypertensives' tibial arteries.