Sexual differences in the development of a hyperthermic reaction in rats after the administration of Freund's complete adjuvant

Application of Freund's complete adjuvant containing killed and dried Mycobacterium butyricum led to a two-phase hyperthermic response in white rats, much more obvious in female than in male rats. The difference seems to be due to a more obvious increase of the tumour necrosis alpha-factor, progesterone, and thyrotropic hormone in the blood of female rats, as well as to prevalence of pyretic activity over the pyretic one in them.