Diazepam and buspirone alter neuropeptide Y-like immunoreactivity in rat brain.
Neuropeptide Y-like immunoreactivity (NPY-LI) was investigated in naIve Sprague-Dawley rats subjected to acute, subchronic (7 days) or chronic (21 days) intraperitoneal treatment with diazepam (1 or 3 mg/kg once daily) or buspirone (1.5 or 5 mg/kg twice daily). NPY-LI was determined by radioimmunoassay in the amygdala, nucleus accumbens, hypothalamus and frontal cortex 24 h after the last dose of the drugs. Amygdala NPY-LI decreased after acute diazepam (3 mg/kg) or buspirone (1.5 mg/kg) and increased after subchronic treatment with both doses of diazepam and after chronic buspirone (1.5 mg/kg) treatment. Both diazepam and buspirone given in subchronic and chronic doses decreased NPY-LI levels in the nucleus accumbens. Hypothalamic NPY-LI changed only after chronic treatment: it decreased after diazepam and increased after buspirone (5 mg/kg). NPY-LI content in the frontal cortex decreased after subchronic diazepam (3 mg/kg) treatment and slightly increased after buspirone. The study has shown that both diazepam and buspirone affect NPY-LI levels in rats. These results suggest that the NPY system in the amygdala and nucleus accumbens is implicated in the anxiolytic effects of the drugs studied.
Krysiak
R
R
Department of Clinical Pharmacology, Silesian University School of Medicine, Katowice, Poland. rmkrysiak@rocketmail.com
Obuchowicz
E
E
Herman
Z S
ZS
D000679:Amygdala / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D001923:Brain Chemistry / Q000187:drug effects*; D002065:Buspirone / Q000494:pharmacology*; D003975:Diazepam / Q000494:pharmacology*; D005625:Frontal Lobe / Q000737:chemistry / Q000378:metabolism; D007031:Hypothalamus / Q000737:chemistry / Q000378:metabolism; D008297:Male; D009714:Nucleus Accumbens / Q000737:chemistry / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley; D017476:Receptors, Neuropeptide Y / Q000032:analysis / Q000276:immunology / Q000378:metabolism*
D014151:Anti-Anxiety Agents; D017476:Receptors, Neuropeptide Y; D003975:Diazepam; D002065:Buspirone