Fate of thyrotropin releasing hormone after binding and stimulation of prolactin release by GH3 cells. Evidence for release of unmodified (3H)-TRH.
GH3 cells which had been exposed for 30 min to (3H)-TRH and had performed their maximun biological response, i.e. increase of prolactin (PRL) release, retained intracellular radioactivity which consisted of chemically unmodified TRH (greater than or equal to 93%). Such preloaded GH3 cells were found able to spontaneously release into the culture medium a radioactive material (3H)-RM) which was analyzed. The kinetics of binding of (3H)-RM to intact GH3 cells and competition with unlabeled TRH were indistinguishable from (3H-TRH. (3H)-RM was able to stimulate PRL release from GH3 cells. In addition thin layer electrophoresis (TLE) revelaed that 90% of (3H)-RM migrated like TRH reference. All these features strongly suggest that (3H)-RM is identical to (3H)-TRH.
D002460:Cell Line; D007700:Kinetics; D010902:Pituitary Gland / Q000378:metabolism*; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism*; D011485:Protein Binding; D013973:Thyrotropin-Releasing Hormone / Q000378:metabolism* / Q000494:pharmacology
D013973:Thyrotropin-Releasing Hormone; D011388:Prolactin