Efects And Mechanisms Of Total Glycosides Of Ranunculus Japonicus On Blood Pressure,hymodynamics In Rats

This thesis is composed of three parts. Partâ… m ainly introduced the effects of Total Glycosides of Ranunculus japonicus (TGRJ) on the BP in anesthetic rats and hypoxia tolerance in mice. Partâ…¡covered my study on the effects of TGRJ on the hemodynamics in anesthetic rats. Partâ…¢reported the effect of TGRJ on intracellular calcium concentration in thoracic aortic vascular smooth muscle cells of rats.Partâ… Effects of TGRJ on BP in anesthetic rats and hypoxia tolerance in miceIn this thesis, changes of heart rate (HR), systolic arterial pressure (SP), diastolic arterial pressure (DP), average arterial pressure (AP) and consecutive electrocardiographicâ…¡were recorded by cannulating femoral artery, right common carotid artery. KM mice were randomized into five groups, each group given orally with medicine continuously for three days. 30 minutes after the last administration, the survival time of the hypoxia tolerance mice under normal pressure were measured. Results showed that TGRJ 120 mg/kg and TGRJ 60 mg/kg can significantly decrease HR, SP, DP, AP. Different doses of TGRJ significantly reduce the oxygen consumption of cardiac muscle in rats by reducing after load, heart rate and cardio working. 120 mg/kg TGRJ can obviously prolong the survival time of mice under the normal pressure (P < 0.05). 60 mg/kg TGRJ can also prolong the survival time of mice under the normal pressure, but has no significantly longer than that of the control group (P > 0.05). And the results concluded that TGRJ reduce HR, arterial blood pressure and oxygen consumption of cardiac muscle in rats. TGRJ 120 mg/kg prolong the survival time of mice; enhance the hypoxia tolerance of mice under normal pressure. Partâ…¡Effects of TGRJ on the hemodynamics in ratsIn this thesis, changes of hemodynamic parameters including heart rate (HR) , systolic arterial pressure (SP) , diastolic arterial pressure (DP) , average arterial pressure (AP ), left ventricular pressure (LVSP) , left ventricular end-diastolic pressure (LVEDP) , left ventricular pressure development during isovolumetric contraction/relaxation (±dp/dt max), and T were recorded by cannulating femoral artery, right common carotid artery and consecutive electrocardiographicâ…¡.Results showed that TGRJ 80 mg/kg and TGRJ 40 mg/kg can significantly decrease HR, SP, DP, AP, LVSP, - dp/dt max and T (P < 0.05 or P < 0.01) in anesthetized rats, but there is no obvious change in LVEDP and + dp/dt max. And the results concluded that TGRJ reduces HR and BP. It has depressive effects on both myocardial contraction and diastole and negative effects on cardiac function in anesthetized rats.Partâ…¢Effects of TGRJ on intercellular calcium in rat vascular smooth muscle cellsVascular smooth muscle cells were incubated with the calcium ion-sensitive fluorescent indicator fluo-3/AM, and then a fluorescence spectrophotometer was applied to measure changs of fluorescence intensity to investigate the effects of TGRJ on intracellular Ca²⁺ concentration in VSMC of rats. Results showed that norepinephrine could significantly promote the Ca²⁺ into intracellular, and different dose of TGRJ could lower the increasing intracellular Ca²⁺ concentration induced by norepinephrine with a maximal respone in some dose-dependent relation, espescially at the concentration of 400μg/ml.