Thyrotropin is not a growth factor for human thyroid cells in culture

摘要: Abstract Thyroid cells, obtained from both normal human tissue and benign nodular goiter, were cultured maintained in vitro 4-18 passages. Cultures with confluent cells accumulated cyclic AMP (10-150 times the basal amount) upon addition of bovine thyrotropin (100 milliunits/ml), indicating that culture a thyrotropin-sensitive adenylate cyclase system. Addition high doses also induced characteristic reversible change morphology cells. The effect on cell growth was studied short- long-term experiments. Thyrotropin reduced [3H]thymidine incorporation dose-dependent fashion all cultures thyroid The maximal inhibition over 24-hr period about 50%. notably sensitive, half-maximal occurred at 100 milliunits per ml. In contrast, hormone had no [3H]-thymidine into glial Low fibroblasts and, doses, stimulation seen. Thyroid grown presence 10 ml for 7-14 days slower rate 24-36% lower numbers saturation density than control dishes, proliferation. data agree studies by others effects corticotropin lutropin target suggest vivo primary action pituitary trophic hormones endocrine tissues is not growth.