Abstract
In rats anesthetized with urethane, intraperitoneal administration of a water-soluble organogermanium compound 2-carboxyethyl germanium sesquioxide (Ge-132) produced a dose-related reduction in either the mean arterial pressure or the heart rate. Both hypotension and bradycardia responses induced by Ge-132 injection were significantly inhibited by pretreatment of the animals with either spinal transection or bilateral vagotomy. The data indicate that Ge-132 induces both hypotension and bradycardia by promoting an activation of the parasympathetic efferent mechanisms and an inhibition of the sympathetic efferent mechanisms. On the other hand, following intraperitoneal injection of Ge-132, increased grooming and head swaying (as shown by an enhancement in fine movements monitored by an electronic activity counter) were provoked. Furthermore, the amphet-amine-induced enhancement in fine movements was potentiated by pretreatment of the animals with Ge-132. Thus, it appears that Ge-132 acts through the catecholaminergic mechanisms in the brain to induce locomotor stimulation in rats.