Hypotensive effect of delsoline
Lian, Q.S.; Feng, G.H.
Zhongguo Yao Li Xue Bao 6(1): 37-40
1985
ISSN/ISBN: 0253-9756 PMID: 3158157 Document Number: 258608
Delsoline (DS) is a C19-diterpenoid alkaloid isolated from the roots of Aconitum finetianum Hand-Mazz. With i.p. DS 1.25, 2.5 in anesthetized dogs and 10 mg/kg in rats, the arterial blood pressure (BP) decreased rapidly by 30%, 47% and 20%, respectively. The reduced BP gradually returned to the control levels. In conscious rats with hypertension induced by ligation of the left renal artery, DS 75 mg/kg (qd .times. 6 d [4 times/day for 6 days]) i.p. resulted in a marked fall of systolic BP accompanied by a slow heart rate and an early enhanced respiration amplitude. Experiments on the superior cervical, celiac and intracardiac vagal ganglia of dogs revealed that DS had a ganglioblocking effect. DS (6-8 mg) injected into the anterior tibial artery of rabbits exhibited a curare-like effect on the anterior tibial muscles. DS produced a negative inotropic action on isolated hearts of frogs and rabbits and intact hearts of dogs. When blood from the right femoral artery was pumped at a constant speed into the left femoral artery in dogs, vascular resistance in left hind-limb and carotid BP were conspicuously reduced by i.v. DS 2.5 mg/kg. When DS (0.25 mg/kg) was injected into the femoral artery, the vascular resistance increased slightly, but the carotid BP did not change. DS (2.5 mg/kg) inhibited the pressor reflex initiated by bilateral carotid occlusion, but did not antagonize or reverse the pressor response resulting from i.v. epinephrine (10 .mu.g) in dogs. The hypotensive effect of DS is mainly attributable to its ganglionic blocking. Its negative cardiac inotropic effect is involved in the hypotensive action. Since the hypotension can be significantly attenuated by diphenhydramine, histamine release may also play a role in the hypotensive effect. The acute LD50 of DS in mice was i.v. 117 mg/kg and i.p. 329 mg/kg.