[The correction of the thyroid status in the surgical treatment of malignant tumors of the stomach and large intestine].

We evaluated changes in thyroid status of patients with carcinoma of the stomach and large intestine in pre- and postoperative periods under the influence of triiodothyronine (T3) prescribed to make up for deficient endogenous hormone. With T3 returning to normal in preoperative period, T4 blood level gets lowered from the upper limit of the norm to the lower one. However these patients show unchanged blood T4 concentration after surgical intervention, while without administration of T3 the level of T4 decreases.

[The pathophysiological significance of the low triiodothyronine syndrome with increased clearance in cancer of the stomach and large intestine].

Investigations designed to study T3 pharmacokinetics under malignant tumors of the stomach and large intestine showed an augmented total T3 clearance, which fact is indicative of enhancement of the processes of 5-monodeiodezing of thyroid hormones. It is to be thought that intensification of T3 metabolism and rise in inverse T3 produced through peripheral conversion of T4 underlie the pathogenesis of that low triiodothyronine syndrome to be encountered in malignant tumors. Since the above mechanism of development of low T3 syndrome has been identified in traumata and infectious diseases, the changes in question might be considered to be one of the links in the general adaptive syndrome directed towards satisfaction of the phagocytosing leucocytes' requirements in the biocydic substrate iodine and augmentation of the production of the fat-mobilizing factor inverse T3.