Further studies on the response of a cytochemical bioassay to thyroid stimulators, using reference preparations of thyrotropin and long acting thyroid stimulator.

The fundamental response of this assay is shown to be a shortening of a latency period prior to a peak of staining after tissue sections have been exposed to either TSH or LATS. The magnitude of the peak for a given tissue is both stimulator and dose independent. Simultaneous exposure to a combined dose of the two stimulator resulted in a further shortening of the latency period, and no evidence of two peaks was observed in the presence of both stimulators. Dose-response curves after exposure to reference preparations of the two stimulators for the same time period (180 s.) were parallel: this indicates that given incremental doses of either stimulator result in indistinguishable increases in the fundamental response of this assay.