Previously, we reported the contribution of the sympathetic nerve system in the maintenance of blood pressure. We studied changes in blood pressure and pulse rate, after the intraperitoneal (i.p.) administration of 5-hydroxydopamine (5-OHDA) at a dose 240mg/kg body weight, in normotensive rats.

In the present study, after i.p. administration of 5-OHDA to normotensive rats, 80mg of red ginseng having vasodilati on and sympathetic nerve exciting effects was given daily for 10 days. During the course of this study, the effects on blood pressure and pulse rate of rats treated with 5-OHDA, as well as concentration of catecholamine in plasma and adrenal glands, were studied. After administration of 5-OHDA, in both red ginseng treated and non-treated groups, biphasic change in blood pressure was observed. That is, transient sharp elevation of blood pressure was followed by rapid lowering to far lower values than the pressure before administration. Subsequently, the pressure rose gradually to the initial level. In this process we found that the recovery time to the initial blood pressure was significantly shorter in the red ginseng-treated group. Administration of red ginseng may accelerate functional recovery of the sympathetic nerve system. On the other hand, pulse rate decreased remarkably after 5-OHDA administration in both groups, but thereafter recovered quickly to the level before administration. Recovery time was also significantly shorter in the red ginseng-treated group than the untreated group. The concentration of plasma catecholamine, measured 11 days after the start of red ginseng administration, was significantly higher than in the untreated group. In contrast, catecholamine in adrenal glands was rather decreased in the red ginseng treated group. These observations suggest the possibility that red ginseng recovers the function of the sympathetic nerve system deranged by 5-OHDA administration.