It has been determined that prostaglandins E2 and F2 alpha being exogenously inoculated during the premetastatic period to mice with metastatic Lewis lung carcinoma in equal degree activate neurocytes of supraoptic and paraventricular hypothalamus nuclei, playing the important role in secretion of peptidergic hypophysial adrenal gland complex, but they exert unequal influence on pituitary body, adrenal cortex and thyroid apparatus. F2 alpha stimulates the pituitary body corticotrophic function, secretory function of spongiocytes and thyrocytes, identifies the thyroxin and triiodothyronine utilization, E2, on the contrary, does not influence these indices or reduces them. Obviously, the mentioned above differences between E2 and F2 alpha may be explained by their different influences on antimetastatic resistance.