ABSTRACT
OBJECTIVE: To investigate the inhibition effect of total alkaloid, total phenolic acid and total volatile oil from Ligusticum chuanxiong on the contraction of the isolated uterine smooth muscle of rats, and to provide reference for clarifying the promoting blood circulation to restore menstrual flow traditional efficacy of L.chuanxiong. METHODS: The isolated uterine smooth muscle of rats were collected and soaked in Locke's solution. Using dimethyl sulfoxide as blank control, verapamil hydrochloride as positive control, the contraction curves of the isolated uterine smooth muscle in rats were recorded with PowerLab electrophysiolograph. Inhibitory effects of total alkaloid, total phenolic acid (mass concentrations of 0. 025, 0. 05, 0. 1 mg/mL) and total volatile oil (0. 04, 0. 08, 0. 16 mg/mL) on the contraction of the isolated uterine smooth muscle of rats induced by oxytocin were evaluated by observing the changes of contraction activity and contraction tension. Inhibitory rates of contraction activity and contraction tension of uterine smooth muscle were calculated. RESULTS: The contraction activity and contraction tension of uterine smooth muscle in rats were increased significantly after treated with oxytocin (P<0. 05 or P<0. 01). Different concentrations of 3 types of compounds from L. chuanxiong all decreased contraction activity and contraction tension of uterine smooth muscle significantly (P<0. 05 or P<0. 01). Compared with blank control, except for 0. 025 mg/mL total phenolic acid, the inhibitory rates of contraction activity and contraction tension of uterine smooth muscle were all decreased significantly (P<0. 05 or P<0. 01)after treated with other concentration drugs or components. CONCLUSIONS: The total alkaloid, total phenolic acid and total volatile oil from L. chuanxiong show certain inhibitory effect on the contraction of isolated uterine smooth muscle in rats, which provide reference for promoting blood circulation to restore menstrual flow use of L. chuanxiong.
ABSTRACT
Authors studied the regulatory mechanism of protein kinase C on the action of acetylcholine in rabbit carotid artery. The arterial rings were myographied isometrically in an isolated organ bath. In this study, acetylcholine relaxed phenylephrine-induced contraction of rabbit carotid artery in the presence of endothelium. In the pretreatment of methylene blue or nitro-L-arginine, the action of acetylchioline was reduced. Pretreatment of phorbol 12-myristate 13-acetate(PMA) attenuated the action of acetylcholine, but PMA did not attenuated it in the presence of staurosporine, suggesting that protein kinase C suppressed the action of acetylcholine. The potency of phorbol ester on the action of acetylcholine was PMA>phorbol 12, 13-dibutyrate(PDBu)>phorbol 12,13-diacetate(PDA), but the direct effect of phorbol on the contraction of arterial rings was PDBu>PMA>PDA. This implied that protein kinase C involved in the contraction of smooth muscle and the attenuation of the action of acetylcholine were different. PMA did not affect on A23187- and sodium nitroprusside-induced vasorelaxation. Acetylcholine increased tissue cGMP contents, which was reduced by PMA. These results suggest that in rabbit carotid artery protein kinase C reduce acetylcholine-stimuated endothelium derived relaxing factor(EDRF) release by affecting membrane receptor, and do not affect on the function of EDRF and cGMP production in the smooth muscle.