Brain catecholamines and adrenocortical activation by morphine in the cat.
Following the administration of 250 mg/kg of alpha-methyl-p-tyrosine (H 44/68) to adult cats, an increase in plasma cortisol was found before any decrease in the contents of noradrenaline in the diencephalon could be observed; this suggests that the induced release of ACTH by H 44/68 administration may be independent of the synthesis impairment of catecholamines. The results observed in cats treated with H 44/68 plus morphine, suggest that the opioid causes an increase in the turnover of noradrenaline. Although different mechanisms for the action of morphine on the pituitary-adrenal system and on brain catecholamines cannot be ruled out, the increased secretion of ACTH induced by morphine could be related to the increased turnover of noradrenaline observed in this study.
Borrell
J
J
Instituto de Endocrinología 'Gregorio Marañón', Centro de Investigaciones Biológicas, C.S.I.C., Madrid, Spain.
Borrell
S
S