tolcapone and lazabemide

Two novel reversible enzyme inhibitors involved in monoamine metabolism are described. The novel and reversible inhibitors are the catechol-O-methyl-transferase (COMT) inhibitors, Ro 40-7592 (3,4-dihydroxy-4'-methyl-5-nitrobenzophenone), and the monoamine oxidase type-B (MAO-B) inhibitor, Ro 19-6327 (N-(2-aminoethyl)-5-chloro-2-pyridine carboxamide HC1). These may be of special therapeutic benefit in Parkinson's and Alzheimer's diseases.

Topics: Aging; Alzheimer Disease; Benserazide; Benzophenones; Catechol O-Methyltransferase Inhibitors; Drug Combinations; Enzyme Inhibitors; Humans; Levodopa; Monoamine Oxidase Inhibitors; Nitrophenols; Parkinson Disease; Picolinic Acids; Tolcapone

The effect of enzyme-inhibiting adjuvants on L-DOPA + benserazide-induced contralateral turning in unilateral 6-hydroxydopamine (6-OHDA)-lesioned rats was studied. Both the number of turns and the duration of turning were examined. Inhibition of MAO-A with 10 mg/kg Ro 41-1049 increased both parameters; inhibition of COMT with 30 mg/kg Ro 40-7592 had a similar effect. In contrast, inhibition of MAO-B with 10 mg/kg Ro 19-6327 did not change turning behavior. A further potentiation of turning behavior was observed after the combined administration of both the MAO-A and COMT inhibitor. MAO-A inhibition in conjunction with MAO-B inhibition prolonged the duration of L-DOPA-induced turning but had no effect on the number of turns. However, in conjunction with COMT inhibition, 10 mg/kg of the MAO-B inhibitor, Ro 19-6327, significantly affected both the number and duration of turning behavior. An even further potentiation of turning behavior was observed after the combined administration of all three enzyme-inhibitors.

Topics: Animals; Antiparkinson Agents; Benzophenones; Catechol O-Methyltransferase Inhibitors; Enzyme Inhibitors; Levodopa; Male; Monoamine Oxidase Inhibitors; Motor Activity; Nitrophenols; Oxidopamine; Picolinic Acids; Rats; Rotation; Thiazoles; Tolcapone