Abstract: | A number of modern research methods were used in experiments on 220 white rats to examine thyroid function at varying times after single immunization with typhoid vaccine. It was found that on the 1st and 2nd days of the observation period, only cAMP level of the thyroid parenchyma decreases. Three, four and seven days following immunization, thyroid function is drastically reduced, which manifests by a decrease in 131I uptake by the thyroid gland. Also decreased were the conversion ratio, the levels of thyroxine and triiodothyronine in blood serum and incorporation of labeled thyroxin by the heart, liver and spleen. During the productive phase of the immunogenesis (days 10, 15, 20 and 25), all the test indicators considerably increase. The phases of the reaction obtained seem likely to be a consequence of reciprocal relationship between the thyroid and sympathoadrenal systems (the inductive period), as well as by the feedback effect (the productive period of antibody formation). The reaction of thyroid function to immunization is regarded as a component of non-specific adaptation response of the body to an extreme irritant, that provides for metabolic reconstruction necessary for the synthesis of antibodies and formation of immune lymphocyte populations. |