RT Journal Article
SR Electronic
T1 A mechanism to explain the antihypertensive action of propranolol.
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 56
OP 63
VO 207
IS 1
A1 R S Tuttle
A1 M McCleary
YR 1978
UL http://jpet.aspetjournals.org/content/207/1/56.abstract
AB The present experiments were designed to measure the direct effects of propranolol on carotid sinus pressoreceptor nerve activity in the semi-isolated, superfused sinus of the cat. Propranolol (5 microgram/ml) significantly enhanced carotid sinus nerve activity at perfusion pressures of 100, 150 and 250 mm Hg. The enhancement was due primarily to the recruitment of new fibers. In similar preparations, perfused at constant flow, propranolol increased sinus resistance in parallel with the increase in sinus discharge. These effects were rapidly dissipated by rinsing with drug-free perfusion solution. The evidence suggests that propranolol may produce a change in either the elastic or autoregulatory modalities of sinus smooth muscle. This may produce a functional "resetting" of the sinus and provide a mechanism to explain the antihypertensive effect of propranolol.