ALTERATION BY PROLONGED ORAL-ADMINISTRATION OF A THYROTROPIN-RELEASING-HORMONE ANALOG, TA-0910, OF THE PITUITARY-THYROID AXIS IN SUBJECTS WITH BRAIN STROKE

We evaluated whether prolonged oral administration of a novel analog o f thyrotropin-releasing hormone (TRH), TA-0910, may change the pituita ry-thyroid axis in human subjects with brain stroke. The subjects were given one oral dose of 2.5-20 mg of TA-0910 daily for 8 weeks, and th en blood levels of TA-0910, thyroid hormones and thyrotropin (TSH) wer e measured. Plasma levels of TA-0910 were elevated with increasing dos es. After administration of TA-0910, the basal levels of thyroid hormo nes and TSH had a tendency to increase and decrease, respectively, but those changes remained in the normal range. The secretion of TSH in r esponse to TRH was not significantly affected by TA-0910 administratio n. No significant changes in other pituitary hormones were observed af ter TA-0910 administration. The present data indicate that prolonged o ral administration of TA-0910 did not significantly alter the pituitar y-thyroid axis in subjects with brain stroke.