Failure of Hypothalamic Tissue to Reinitiate Thyrotropin Production By Mouse Pituitaries in Tissue Culture.

Contrary to Guillemin's findings regarding the reinitiation of corticotropin production by pituitary explants in the presence of hypothalamic tissue, no thyrotropin was produced by mouse pituitary explants even after addition of growing hypothalamic tissue. Since the assay procedures employed would have detected 3 mU of thyrotropin, less than 4% of the original thyrotropin content of the explants was produced per week.