Anxiogenesis induced by nitric oxide synthase inhibition and anxiolytic effect of melanin-concentrating hormone (MCH) in rat brain.
In this study, the involvement of nitric oxide (NO) in the mechanism of anxiety was investigated. The rats received an intraamygdaline or intrahippocampal injection of the nitric oxide synthase inhibitor, N(G)-nitro-l-arginine (L-NOARG), and were then tested in the plus-maze test. L-NOARG induced a decrease in the time spent by rats in the open arms. Conversely, the administration of the melanin-concentrating hormone (MCH) into these structures increased the number of entries into the open arms as well as the time spent on them. MCH injected in rats pretreated with L-NOARG also was able to revert the anxiogenic effects of L-NOARG in amygdala.
Monzón
M E
ME
Laboratorio de Fisiología, Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba (UNC), 5000 Córdoba, Argentina. fisiol@mail.fcq.unc.edu.ar
Varas
M M
MM
De Barioglio
S R
SR
D000679:Amygdala / Q000187:drug effects / Q000201:enzymology; D000818:Animals; D001921:Brain / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects / Q000201:enzymology; D007028:Hypothalamic Hormones / Q000494:pharmacology*; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008543:Melanins / Q000494:pharmacology*; D009389:Neovascularization, Pathologic; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D019335:Nitroarginine / Q000494:pharmacology; D010100:Oxygen / Q000378:metabolism*; D010907:Pituitary Hormones / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
D004791:Enzyme Inhibitors; D007028:Hypothalamic Hormones; D008543:Melanins; D010907:Pituitary Hormones; D019335:Nitroarginine; D009569:Nitric Oxide; C019463:melanin-concentrating hormone; D019001:Nitric Oxide Synthase; D010100:Oxygen