Effect of stress and cholinergic stimulation on ACTH release in alpha-methyl-dopa pretreated rats.
Pituitary-adrenocortical function and the changes of hypothalamic catecholamine content were studied following alpha-methyl-dopa treatment in rats. After three-day administration of alpha-methyl-dopa the plasma corticosterone concentration increased significantly and at the same time ether stress failed to elicit a pituitary-adrenocortical response. Moreover, the alpha-methyl-dopa pretreatment prevented the facilitatory effect of physostigmine on pituitary-adrenocortical activation. As the result of alpha-methyl-dopa treatment the norepinephrine content decreased significantly and the amount of compounds measured as dopamine (dopamine, alpha-methyl-dopamine and alpha-methyl-dopa) increased in the hypothalamus. It is concluded that the impaired metabolism of catecholamines may inhibit the pituitary-adrenocortical activation to stimulation, and that not only norepinephrine and dopamine, but other phenylalanine derivatives and alpha-methyl-dopa may also influence the responsiveness of pituitary-adrenocortical function.
D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D000818:Animals; D003345:Corticosterone / Q000097:blood; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism; D004298:Dopamine / Q000502:physiology; D005260:Female; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects; D007031:Hypothalamus / Q000032:analysis / Q000187:drug effects; D008297:Male; D008750:Methyldopa / Q000494:pharmacology*; D009638:Norepinephrine / Q000032:analysis; D010277:Parasympathomimetics / Q000494:pharmacology*; D010830:Physostigmine / Q000494:pharmacology; D010913:Pituitary-Adrenal System / Q000187:drug effects*; D051381:Rats; D013312:Stress, Physiological / Q000378:metabolism*
D010277:Parasympathomimetics; D008750:Methyldopa; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D010830:Physostigmine; D004298:Dopamine; D003345:Corticosterone; D009638:Norepinephrine