THE EFFECT OF PURIFIED BOVINE THYROIDSTIMULATING HORMONE IN MAN. II. LOSS OF EFFECTIVENESS WITH PROLONGED ADMINISTRATION*

Abstract

Four normal human subjects received repeated doses of a highly purified bovine thyrotropin (prepared by the method of Pierce et al.) and the response was monitored by the rise in the two-hour thyroidal uptake of I132. All subjects initially responded to doses of TSH varying from 0.0032 to 0.050 unit per Kg. of body weight. All became refractory to the effects of the TSH after five to twenty-nine doses. Sera obtained after development of resistance contained hemagglutinating and neutralizing antibodies to thyrotropin.