Effect of thyrotropin-releasing hormone on microtubules in GH3 cells.
The effect of thyrotropin-releasing hormone (TRH) on the tubulin-microtubule system in GH3 cells was investigated. Prolactin (PRL) secretion by GH3 cells was stimulated by TRH at 1, 5, and 10 min of incubation. The polymerized tubulin levels increased from 0.4 units micrograms-1 protein in control cells to 0.6 units micrograms-1 protein in cells incubated with TRH for 1 min. Soluble tubulin levels increased from 0.8 units microgram-1 protein in control cells to 1.2 units micrograms-1 protein in cells exposed to TRH for 5 min. Tubulin levels were similar in control cells and cells treated with TRH for 10 min. These results suggest that TRH-stimulated PRL secretion is accompanied by a shift in the equilibrium between tubulin pools.
D000818:Animals; D001345:Autoradiography; D015151:Immunoblotting; D008870:Microtubules / Q000187:drug effects* / Q000378:metabolism; D010911:Pituitary Neoplasms / Q000378:metabolism* / Q000648:ultrastructure; D011388:Prolactin / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D013268:Stimulation, Chemical; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D013973:Thyrotropin-Releasing Hormone; D011388:Prolactin