Effects of morphine on hypothalamic corticotropin-releasing factor (CRF), norepinephrine and dopamine in non-stressed and stressed rats.
The effects of morphine on the hypothalamic corticotropin-releasing factor (CRF), norepinephrine (NE) and dopamine (DA) concentrations were investigated in non-stressed and stressed rats. Acutely administered morphine stimulated both the synthesis and release of CRF in the hypothalamus, thereby activating the pituitary-adrenocortical system in non-stressed rats, but inhibited the stress-induced CRF synthesis and ACTH-corticosterone secretion. Either a morphine or ether-laparotomy stress reduced NE and DA concentrations in the hypothalamus. A pretreatment with morphine inhibited the stress-induced reduction in the hypothalamic NE and DA concentrations, and induced a significant increase in the DA concentration. These observations suggest that hypothalamic NE and DA are involved in morphine-induced changes in hypothalamo-pituitary-adrenocortical (HPA) activity and that endogenous opiates have a role in regulating CRF secretion by interacting with hypothalamic biogenic amines.
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D003345:Corticosterone / Q000097:blood; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009638:Norepinephrine / Q000378:metabolism*; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D013312:Stress, Physiological / Q000503:physiopathology*
D009020:Morphine; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D004298:Dopamine; D003345:Corticosterone; D009638:Norepinephrine