Inhibition by papaverine of calcium movements and tension in the smooth muscles of rat vas deferens and urinary bladder.

Abstract

SUMMARY1. Papaverine, up to 150 /M, was without effect on resting tension of vas deferens and urinary bladder smooth muscle strips, but caused a dose-dependent inhibition of the phasic component of the 100 mM-K contracture. At 150 FM, papaverine caused an 80 and 60 % inhibition ofphasic tension in vas deferens and urinary bladder muscle respectively.2. Papaverine caused a marked dose-dependent reduction in the tonic component of 100 mM-K contractures in both preparations. At 150 /M, papaverine often relaxed preparations below initial starting tension.3. Addition of 150 /ZM-papaverine to incubation media caused a fall of 25-30 % in 45Ca uptake by both preparations.4. Papaverine at 150 /LM caused a small fall in resting 45Ca efflux from vas deferens and a larger fall in efflux from bladder muscle. However, this papaverine concentration caused a large inhibition of the 45Ca uptake by and 45Ca efflux from both preparations when stimulated by high-K depolarization.5. Papaverine at 150 ,lM was without significant effect on Ca binding by either microsomes or mitochondria isolated from both vas deferens and urinary bladder smooth muscle.6. The main site of papaverine action appears to be on the Ca-influx mechanism responsible for regulating Ca entry during prolonged K depolarization.

Relationship between cytosolic calcium concentration and force in the papaverine‐induced relaxation of medial strips of pig coronary artery

“…Electrophysiological studies showed that papaverine, irrespective of the level of cyclic AMP, inhibits VOCs to cause relaxation of the dog basilar artery. In other electrophysiological studies (Itoh et al, 1981;Brading et al, 1983) and 45Ca2l studies (Huddart et al, 1984), papaverine seemed to inhibit Ca2l influx as a means of causing relaxation of smooth muscle.…”

Papaverine Blocks hKv1.5 Channel Current and Human Atrial Ultrarapid Delayed Rectifier K+ Currents

“…It blocks the contractile response to excitatory agents (Tashiro and Tomita, 1970;Brading et al, 1983;Huddart et al, 1984). Because of those relaxant effects on smooth muscles, papaverine has been used as a vasodilator agent (Wilson and White, 1986;Franz et al, 1991;Newell et al, 1999) and as a therapeutic agent for renal colic (Jonsson et al, 1987) and penile impotence (Handelsman, 1990).…”

Anxiolytic effect of carbamazepine in the elevated plus-maze: possible role of adenosine

“…Furthermore, the opposite effects of aminophylline and of CBZ cancelled each other when effective doses of the two drugs were combined. However, because papaverine is known to yield other neuronal effects besides those on the adenosinergic system (Triner et al 1970;Huddart et al 1984;O'Hara and Ono 1987), and the above behavioural antagonism could be due to interference with different functionally opposed neuronal systems, additional experimental evidence is necessary to test the adenosine hypothesis of CBZ anxiolytic action.…”