Hypotensive effect of dimethyl cycleanine bromide
Sun, Z.; Yang, X.Y.; Dai, Z.L.; Jin, G.Z.; Zhang, Z.D.
Zhongguo Yao Li Xue Bao 1(1): 23-27
1980
ISSN/ISBN: 0253-9756 PMID: 6175170 Document Number: 163161
Cycleanine was isolated from Stephania epigeae Lu and its cardiovascular effects in dogs are reported. In anesthetized dogs i.v. injections of dimethyl cycleanine bromide (or iodide) at the dosage of 0.5-1.0 mg/kg produced a prompt fall of arterial blood pressure of .apprx. 70-110 mm Hg. The decreased blood pressure gradually returned to its original levels in 30 min. Hypotension induced by cycleanine was accompanied by a bradycardia and a shallow but rapid respiration. The mechanism of hypotensive effect of cycleanine was studied. Ganglionic transmission was inhibited, histamine release in arterial blood was increased and cardiac output was decreased. These were apparently the main causes of the hypotension. The acute LD50 by i.p. injection in mice was 2.9 (95% fiducial limits 2.4 and 3.1) mg/kg. In subacute toxic examination in rats, serum GPT [glutamic-pyruvic transaminase] and NPN [non-protein nitrogen] were not significantly changed after administration of cycleanine. Histology did not show any pathological changes. Body weight gain was retarded.