Year: 2012
Type: article
Abstract: Pituitary lactotrophs are excitable cells that exhibit spontaneous, calcium influx triggering prolactin (PRL) secretion to stimulate lactation. Lactotrophs express estrogen receptors (ER) and are a well established estrogen-responsive cell system. 17B-estradiol (E2) is known to directly affect lactotrophs by increasing PRL transcription and biosynthesis, intracellular Ca2+ concentration ([Ca2+]i) and PRL secretion. This study demonstrates that the MMQ clonal cell line, isolated from the 7315a rat pituitary tumor, is a model lactotroph cell line that is E2-responsive. Spontaneous and evoked Ca2+ transients were especially sensitive to L-type channel block, but not affected by block of omega-conotoxin-GVIA-sensitive CaV channels or TTX-sensitive voltage-gated Na+ (Nav) channels. A population of 17B-Estradiol-treated cells exhibited enhanced spontaneous Ca2+ oscillation amplitude and frequency and depolarization-evoked Ca2+ transients. E2 treatment significantly enhanced the Ca2+ response through dihydropyridine-sensitive voltage-gated Ca2+ (Cav) channels, suggesting that 17B-Estradiol increased L-type Ca2+ channel genomic expression.
Author: Monika Pauckova
Language: English
Subfield: Endocrinology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W133039660