[Effects of monoamine oxidase B inhibitor and MPTP (1-methyl-4-phenyl-1,2,3,6-tetra-hydropyridine) on enkephalin levels in mice].

The results of injecting 1-methyl-40 henyl-1,2,3,6-tetra-hydropyridine (MPTP) intraperitoneally to C57-BL black mice in doses of 36 mg/kg body weight each day for 7 days were analysed. Twelve days after the last MPTP injection, the levels of methionine-enkephalin (MEK) and leucine-enkephalin (LEK) in the mice striatum bodies were determined with radioimmunoassay. In the mice receiving MPTP, the average levels as compared with the controls were reduced by 75% for MEK (P less than 0.001) and by 66% for LEK (P less than 0.002). The levels of MEK and LEK in the mice receiving the monoamine oxidase inhibitor as well as MPTP did not differ significantly from the levels in the controls. The experimental data suggest that MPTP can affect the enkephalin system, while L-deprenyl can prevent MPTP-induced enkephalin depletion in the mice striatum bodies.