Beta-endorphin concentrations in pituitary and brain areas of animals bearing pituitary hormone secreting tumors

Beta-endorphin-like immunoreactivity was measured in the pituitary and brain areas of rats and mice bearing tumors which secrete different pituitary hormones. The DCCXLIIId tumor secretes both luteinizing hormone and follicle stimulating hormone, and the AtT20 tumor secretes corticotropin, beta-lipotropin and beta-endorphin. Beta-endorphin concentrations in the pituitary and brain areas of rats or mice bearing these tumors are similar to those present in the respective controls, but for a decrease in the hindbrain of AtT20 tumor bearing mice. We conclude that peripheral concentrations of gonadotropins, corticotropins, beta-lipotropin and beta-endorphin do not affect the pituitary and brain concentrations of beta-endorphin.