The effects of stress on central nervous system concentrations of the opioid peptide, dynorphin.
Dynorphin is an opioid peptide distributed throughout the central nervous system. Using a highly specific and sensitive radioimmunoassay for dynorphin we have examined the effect of stress on ir-dynorphin levels in the cortex and hypothalamus of the rat. Stresses related to food ingestion, i.e. starvation (72 hr), mild tail-pinch and insulin (10 U/kg) induced hypoglycemia all produced alterations in ir-dynorphin levels in the cortex. In contrast, restraint stress and 10-minute swim stress produced no changes in ir-dynorphin levels in either the hypothalamus or the cortex. Two hour exposure at 4 degrees C resulted in a fall in ir-dynorphin levels in the hypothalamus. Taken together with previously reported pharmacological effects of dynorphin-(1-13), these results suggest a possible physiological role for dynorphin in appetite and temperature regulation.
D000818:Animals; D000918:Antibody Specificity; D001923:Brain Chemistry; D003429:Cross Reactions; D004399:Dynorphins; D004723:Endorphins / Q000276:immunology / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology; D008297:Male; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D012149:Restraint, Physical; D013217:Starvation / Q000378:metabolism; D013312:Stress, Physiological / Q000378:metabolism*
D004723:Endorphins; D007328:Insulin; D004399:Dynorphins