BIOASSAY OF THYROTROPIC HORMONE BY WEIGHT RESPONSE OF BOVINE THYROID SLICES1

Publisher Website
Google Scholar
Abstract
A new method for bioassay of thyrotropic hormone (TSH), based on the weight response of beef thyroid slices incubated 21 hours at 38[degree] C in a shaking incubator, is presented. TSH induced higher final weights compared with the control group. Histoquantitative evidence is presented that the response consisted of swelling of the follicles, due to the entry of fluid from the incubation medium. The response was blocked by preheating the slice for 10 minutes at 50[degree] C, or by the presence of dilute concentrations of dinitro-phenol, cyanide, or mercuric ion, but was not blocked by fluoride, thiocyanate, propylthiouracil, or iodide. The assay was specific; of adequate range; sensitive to [less than or equal to] 0.01 U.S.P. milliunits of TSH/ml; as precise as other reported current methods, with a median wavelength of 0.28; and unusually simple and economical.