Effect of Korea red ginseng on the blood pressure in conscious hypertensive rats

The change of blood pressure and heart rate after intravenous injection of Korea red ginseng (KRG) were studied in the conscious normotensive and one-kidney, one-clip Goldblatt hypertensive (1K, 1C-GBH) rats. Crude saponin (CS) of KRG (50, 100 mg/kg iv) induced a hypotensive effect and bradycardia in a dose-dependent manner in the anesthetized rats. On the other hand, CS of KRG (100 mg/kg) induced a hypotensive effect and reflex tachycardia in the conscious rats. Saponin-free fraction (SFF) of KRG did not affect them in the anesthetized normotensive rats ( P>.05). The maximal hypotensive effect by CS of KRG in the conscious 1K, 1C-GBH hypertensive rats and l-nitroarginine methyl ester ( l-NAME, 40 mg/kg)-treated conscious hypertensive rats was not different from that of conscious normotensive rats (Δ31.6±6.3, Δ27.5±5.8 vs. Δ26.7±4.3 mmHg, P>.05). However, pretreatment of l-NAME significantly inhibited the reflex tachycardia by CS of KRG (70.8±7.0 vs. 30.6±15.0 bpm, P