THE ROLE OF THE THYROID GLAND IN THE CONTROL OF THE CITRIC ACID CONTENT IN PLASMA OF RABBITS AND GUINEA PIGS

Abstract

In thyroidectomized rabbits treated with l-thyroxine, the differences in citric acid content on the 7th and 14th day of hormone treatment were insignificant as compared with initial values and with saline treated animals. Under the influence of thyrotropin (TSH) the citric acid content in the guinea pig increased. Thyroidectomized rabbits showed a statistically insignificant increase in citric acid content after adrenalectomy. Conversely, those animals which had been treated with l-thyroxine before adrenalectomy showed a high citric acid level in the plasma. Since a marked hypercitricemia followed adrenalectomy in l-thyroxine treated animals and little increase in citric acid was noted in previously thyroidectomized animals, it was assumed that the thyroid gland is one of the factors which cause an increase in citricemia. The increase in plasma citric acid content after TSH treatment was in agreement with the hypothesis of decreased ACTH secretion in hyperthyroidism after TSH administration.