Thyrotropin releasing hormone stimulation of prolactin release. Evidence for a membrane potential-independent, Ca2+-dependent mechanism of action.
Year: 1980
Type: article
Abstract: Thyrotropin releasing hormone (TRH) and high extracellular K+ induce prolactin release from rat pituitary cells (GH3 cells) in culture. TRH, as well as high K+ (50 mM), was shown to increase 45Ca2+ efflux from these cells. The effects of TRH and high K+ on membrane polarization was determined indirectly using the lipophilic cation, triphenylmethyl phosphonium ion (TPMP+). The resting membrane potential of GH3 cells was -50 +/- 1.7 mV. TRH, which induced a marked increase in 45Ca2+ efflux and stimulated prolactin release, had no effect on membrane polarization measured simultaneously. High K+, which also increased 45Ca2+ efflux and prolactin release, depolarized the GH3 cell as evidenced by a marked increase in [3H]TPMP+ efflux. These results suggest that TRH and high K+ may act via different mechanisms to increase intracellular Ca2+ and stimulate prolactin release.
Source: Journal of Biological Chemistry
Author: M.C. Gershengorn
Institutions: NYU Langone Health, New York University
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
OpenAlex ID: W1519419846