The effect of noradrenergic receptor blocking agents on 5-hydroxytryptamine turnover in the brain of rats.
Phenoxybenzamine (PB), phentolamine (PT) and aceperone (AC) in doses of 25 and 50 mg/kg increased cerebral noradrenaline (NA) turnover so these doses were regarded as blocking brain NA receptors. PB (50 mg/kg), PT (50  mg/kg) and AC (25 and 50 mg/kg) accelerated also the turnover of brain 5-HT. PT in a dose of 25 mg/kg counteracted deceleration of 5-HT turnover induced by clonidine but not by quipazine. Almost the same extent of decrease in 5-HIAA concentration after quipazine was observed in controls as in the rats pretreated with NA blockers in a dose of 25 mg/kg. On the contrary PT given in a dose of 50 mg/kg antagonized significantly the effect of quipazine. The results indicate that NA blockig agents given in lower doses do not affect the 5-HT system, however after higher doses such effect is possible.
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D002090:Butyrophenones / Q000494:pharmacology; D003000:Clonidine / Q000494:pharmacology; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008297:Male; D008781:Methyltyrosines / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism; D010643:Phenoxybenzamine / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D011804:Quinolines / Q000494:pharmacology; D051381:Rats; D011941:Receptors, Adrenergic / Q000187:drug effects*; D012701:Serotonin / Q000378:metabolism*
D002090:Butyrophenones; D008781:Methyltyrosines; D010879:Piperazines; D011804:Quinolines; D011941:Receptors, Adrenergic; D010643:Phenoxybenzamine; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D003000:Clonidine; D009638:Norepinephrine; D010646:Phentolamine