Antiparkinsonian properties of a nerve growth factor dipeptide mimetic GK-2 in in vivo experiments.

An intraperitoneal injection of GK-2 (dipeptide mimetic of nerve growth factor, 0.01-5.00 mg/kg) 24 h before the adverse exposure reduced the severity of haloperidol-induced catalepsy in rats. This agent retained the activity after oral administration in a dose of 10 mg/kg. An intraperitoneal injection of GK-2 in a dose of 1 mg/kg reduced the severity of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced parkinsonian syndrome in mice. Administration of GK-2 45 min after haloperidol treatment was also followed by a decrease in the degree of catalepsy. The repeated intraperitoneal treatment with GK-2 in a dose of 1 mg/kg after intrastriatal injection of 6-hydroxydopamine was shown to prevent the development of apomorphine-induced rotations in rats.