[Informative value of tissue oxygen tension in thyrotoxicosis]

Oxygen tension (pO2) and the rate of its utilization (U) in the skin of patients with various functional conditions of the thyroid gland, and also after a single dose of thyroidin was determined. pO2 proved to rise in patients with moderately severe thyrotoxicosis and under conditions of experimental hyperthyroidization; further thyrotoxicosis development was attended by a tendency to pO2 reduction, but U rose considerably. A paralleled decrease of pO2 and U indices was seen in hypothyroidism. A different genesis of tissue hypoxia arising at the late stages of thyrotoxicosis and in case of the thyroid gland hypofunction was supposed: in the first case it was caused by disproportion between oxygen supply and utilization, and in the second--by U reduction, and, as a result, by diminished oxygen supply to the cell (because of decreased transport possibilities of the circulatory system) and to the tissues. Due to this the oxygen gradient providing oxygen diffusion into the cell proved to fall significantly. A conclusion was drawn on the necessity of comparing the pO2 and U indices for the assessment of tissue oxygen utilization under clinical conditions.