@Article{biocell.2008.32.211,
AUTHOR = {MARTHA LAFARQUE, LILIANA OLIVEROS},
TITLE = {A 66-kDa protein of bovine hypophyseal <i>Pars tuberalis</i> induces luteinizing hormone release from rat <i>Pars distalis</i>},
JOURNAL = {BIOCELL},
VOLUME = {32},
YEAR = {2008},
NUMBER = {3},
PAGES = {211--218},
URL = {http://www.techscience.com/biocell/v32n3/37742},
ISSN = {1667-5746},
ABSTRACT = {In this study, evidence for a factor secreted by bovine hypophyseal <i>pars tuberalis</i> that stimulates luteinizing hormone (LH) release from rat <i>pars distalis</i> cells is shown. The secretion products of bovine <i>pars tuberalis</i> cells into the culture medium were assayed on dispersed rat <i>pars distalis</i> cells in 30 min incubations and superfusion experiments. The culture medium from <i>pars tuberalis</i> total cell populations, added at a dose of 6 μg per tube, induced the greater LH release from <i>pars distalis</i> cells, without effect on follicle stimulating hormone (FSH) release. After <i>pars tuberalis</i> cells separation on a discontinuos Percoll gradient, only the culture medium of cells from 50 and 60% strength Percoll were able to release LH from rat <i>pars distalis</i> cells. Therefore, cell fractions from 50 and 60% strenght Percoll were cultured together. To elicit maximal LH release (6 times the basal output), with the addition of 2 μg of <i>pars tuberalis</i> protein was required, suggesting that these cells produce the factor or factors which affect pars distalis gonadotrope cells. After applying the <i>pars tuberalis</i> culture medium on 12% SDS-PAGE, the band with biological activity was that of 66-kDal. Fifty ng protein of its eluate released almost 9 times the basal output of LH from <i>pars distalis</i> cells. Results suggest a modulating effect of a protein from the bovine <i>pars tuberalis</i> on rat cultured gonadotrope cells from the <i>pars distalis</i>.},
DOI = {10.32604/biocell.2008.32.211}
}