Effects Of Hepatocyte Growth Factor On Blood Pressure In Spontaneously Hypertensive Rats

Objective: To investigate the effect of HGF on blood pressure, vascular endothelial system and renin-angiotensin system (RAS) in spontaneously hypertensive rats, further more, to discuss the mechanisms between HGF and hypertension.Methods: Rats with 14-weeks-old, weighting 200-250 g, were randomly divided into the experimental and spontaneous hypertension groups, WKY rats were serves as the control group, with 12 animals in each group.Rats in the experimental group were administrated 5, 10, 15, 20, and 25μg/kg HGF per 24 hours, the partes aequales sodium chloride was injected into the spontaneous hypertension and control groups. Five minutes after administration, systolic pressure and heart rates were measured. The rats were sacrificed and harvested 2 mL and aorta tissue 6-8mg, The effect of HGF on systolic pressure and heart rates, and levels of serum nitrogen monoxidum (NO), plasma endothelin (ET), as well as angiotensinⅡ(AgⅡ) were detected by colorimetry and radio-immunity , aorta HGFmRNA by reverse transcripition - poly merase chain reaction (RT-PCR) methods .Results: When injected 5μg/kg HGF, the blood pressure did not significantly change. After 10μg/kg HGF injection, the blood pressure began to decrease and reached a peak after 30 minutes, gradually recovered after 1 hour, and back to the normal after 5 hours. Injection of 20μg/kg has largest effect on rats, with reduced contractive pressure 40-50mmHg, but no significantly changes appeared by adding HGF dose. There were no significantly differences of heat rate and blood pressure between the two control groups. Compared with the spontaneous hypertension group, the levels of ET and AgⅡwere decreased, however, the level of NO was increased (P < 0.05). WKY rats the level of aorta HGFmRNA is more by SHR. Conclusions: Intravenous Injection with HGF can immediately reduce systolic pressure and heart rates induced by spontaneous hypertension, which shows concentration-dependent and time-dependent manner in definite dose range. HGF, vascular endothelial system and RAS may involve in the process of regulating blood pressure . WKY rats the level of aorta HGFmRNA is more by SHR. the level of aorta HGFmRNA of SHR no change may because of HGF is protion.