Increased hypothalamic sensitivity to estrogen inhibition induced by L-dopa, phenytoin, epithalamin, and phenformin in old rats

Effect of Treatment with Phenformin, Diphenylhydantoin or <i>L</i>-Dòpa on Life Span and Tumour Incidence in C3H/Sn Mice

“…It is noteworthy in this respect that an anahormone of ACTH, capable of inhibiting glucocorticoid production, can reduce mam mary tumour incidence in C3H mice (Butovs kaya and Krylova, 1975). Finally, it cannot be ruled out that the reducing effect of phenformin and diphenylhydantoin treatment on the threshold of sensitivity of hypothalamopituitary complex to inhibition by estrogens (Dilman and Anisimov, 1975) is actually related to the rise in the concentration of biogenic amines in the brain, especially that of dopa mine. Dopamine is known to inhibit the secre tion of prolactin, one of the major modifiers of mammary carcinogenesis in rodents (Welsch and Nagasawa, 1977).…”

“…which inhibits the secretion of insulin and glucocorticoid hormones, may be instrumental in dealing with ageing-associated metabolic disturbances . Finally, these two drugs as well as ¿-dopa reduce the threshold of sensitivity of the hypo thalamopituitary complex to inhibition by estrogens (Dilman and Anisimov, 1975), i.e., …”