Open Access
ARTICLE
A 66-kDa protein of bovine hypophyseal Pars tuberalis induces luteinizing hormone release from rat Pars distalis
MARTHA LAFARQUE, LILIANA OLIVEROS
Cátedra de Fisiología. Laboratorio de Biología de la Reproducción (LABIR), Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, Argentina.
Address correspondence to: Liliana Oliveros. Cátedra de Fisiología. Laboratorio de Biología de la Reproducción (LABIR), Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, ARGENTINA. E-mail: lolive@unsl.edu.ar
BIOCELL 2008, 32(3), 211-218. https://doi.org/10.32604/biocell.2008.32.211
Abstract
In this study, evidence for a factor secreted by bovine hypophyseal
pars tuberalis that stimulates luteinizing hormone (LH) release from rat
pars distalis cells is shown. The secretion products of bovine
pars tuberalis cells into the culture medium were assayed on dispersed rat
pars distalis cells in 30 min incubations and superfusion experiments. The culture medium from
pars tuberalis total cell populations, added at a dose of 6 μg per tube, induced the greater LH release from
pars distalis cells, without effect on follicle stimulating hormone (FSH) release. After
pars tuberalis 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
pars distalis 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
pars tuberalis protein was required, suggesting that these cells produce the factor or factors which affect pars distalis gonadotrope cells. After applying the
pars tuberalis 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
pars distalis cells. Results suggest a modulating effect of a protein from the bovine
pars tuberalis on rat cultured gonadotrope cells from the
pars distalis.
Keywords
Cite This Article
LAFARQUE,, M. (2008). A 66-kDa protein of bovine hypophyseal
Pars tuberalis induces luteinizing hormone release from rat
Pars distalis.
BIOCELL, 32(3), 211–218. https://doi.org/10.32604/biocell.2008.32.211
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