EFFECT OF THYROID-HORMONE ON URINARY-EXCRETION OF EPIDERMAL GROWTH-FACTOR

Thyroid hormones were demonstrated to upregulate the synthesis of epid ermal growth factor (EGF) mRNA and proEGF in the kidneys in vivo. This prospective study was performed to examine the extent of the hypothyr oid state in modulating EGF excretion in the urine (U-EGF; n = 23). Pa tients with thyroid cancer were serially followed up from the euthyroi d status, which was retained by thyroxine supplement after thyroidecto my, to the hypothyroidism in preparing for I-131 whole body scanning. Paired thyroid function panel, Including triiodothyronine (T-3), thyro xine (T-4), thyroid-stimulating hormone (TSH), and U-EGF levels were m easured on a weekly basis. Logarithmically transformed values of U-ECF were inversely correlated with TSH serum levels (p = 0.0000), but pos itively associated with T-4 levels (p = 0.0005). No apparent correlati on was observed with the T-3 serum content, age and gender of the pati ents (p > 0.1, respectively). If the interval of measurement was taken into consideration, serum TSH was the most significant factor in asso ciation with U-EGF (p = 0.0003). Our data indicate that excretion of E GF in human urine depends substantially upon thyroid hormone support.