[Effects of benzyltetrahydropalmatine on rat portal vein and guinea pig myocardium].
In isolated rat portal vein, benzyltetrahydrophalmatine (BTHP) 0.3-100 mumol.L-1 dose-dependently increased the spontaneous mechanical activity. However, BTHP 300 mumol.L-1 showed an inhibitory effect on the spontaneous contraction. BTHP 200 mumol.L-1 reversed positive staircase phenomenon to negative ones in left atrium of guinea pig and inhibited the amplitude and Vmax and shortened the action potential duration (APD50) of the slow action potentials induced by high K+ (24 mmol.L-1) in guinea pig papillary muscles. BTHP reduced also the contractile force in papillary muscles of guinea pig. These results suggest that BTHP possesses calcium antagonistic effect in high concentration.
Xia
G J
GJ
Department of Pharmacology, Tongji Medical University, Hankou, China.
Yao
W X
WX
Song
D
D
Jiang
M X
MX
D000200:Action Potentials / Q000187:drug effects; D000470:Alkaloids / Q000494:pharmacology*; D000818:Animals; D001600:Berberine Alkaloids / Q000494:pharmacology*; D002118:Calcium / Q000037:antagonists & inhibitors*; D003864:Depression, Chemical; D005260:Female; D006168:Guinea Pigs; D006325:Heart Atria; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009200:Myocardial Contraction / Q000187:drug effects*; D010210:Papillary Muscles / Q000187:drug effects; D011169:Portal Vein / Q000187:drug effects; D051381:Rats
D000470:Alkaloids; D001600:Berberine Alkaloids; C060778:benzyltetrahydropalmatine; D002118:Calcium