Central action of 3-methoxy-4-hydroxymandelic acid in rats
Kleinrok, Z.; Jagiello-Wójtowicz, E.
Acta Physiologica Polonica 26(5): 481-491
1975
ISSN/ISBN: 0044-6033 PMID: 1241503 Document Number: 92087
3-Methoxy-4-hydroxymandelic acid (VMA) administered intraventricularly [i.v.c.] in doses of 50 and 250 .mu.g exerts a short-lasting stimulating action which changes to an inhibitory effect after 10-20 min. Larger doses of VMA (0.5, 1.0, 1.5, 2.0 and 2.5 mg) had in the rats an inhibitory effect, lasting up to several hours. VMA in a dose of 500 .mu.g prolonged sleep induced with hexobarbital (50 mg/kg i.p.) or chloral hydrate (240 mg/kg i.p.), potentiated the action of reserpine and abolished the hyperactivity and hyperthermia of animals subjected to the action of nialamide and L-dopa. Phentolamine in a dose of 20 .mu.g i.v.c. had no effect, and in a dose of 100 .mu.g potentiated the inhibitory action of 50 .mu.g of VMA. Propranolol (150 .mu.g i.v.c.) reversed the inhibitory action of VMA (500 .mu.g) no motor activity.