Brain monoamines and plasma corticosterone in stressed rats treated with dextroamphetamine or propranolol
Pericic, D.; Manev, H.; Boranic, M.; Poljak-Blazi, M.
Biomedicine and PharmacoTherapy 36(6-7): 291-296
1982
ISSN/ISBN: 0753-3322 PMID: 7183343 Document Number: 183930
Rats were treated with injections of dextroamphetamine or propranolol, and stressed by restraint lasting 3 h. This was performed once, or repeated daily for 4 days. Controls included drug treatment without subsequent stress, and restraint without drug pretreatment. Concentrations of 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), noradrenaline in non-stressed animals alike. Dextroamphetamine did not abolish the increase of brain 5-HIAA, nor the decrease of brain noradrenaline induced by stress. No correlation between plasma corticosterone and brain monoamine levels was observed under the experimental conditions. Although only dextroamphetamine altered the basal corticosterone level, evidently, both dextroamphetamine and propranolol affect plasma corticosterone levels if given in combination with repeated stress, but the effect is delayed rather than immediate. In rats immunized with sheep erythrocytes, the neurotransmitter response to the stress and drugs slightly differed from that in nonimmunized rats. This may indicate subtle neuroendocrine adjustments to the antigen challenge.