title: Effect of insulin on sulfated proteoglycan synthesis in cultured smooth muscle cells from pig aorta.
abstract: The effect of insulin upon proteoglycan synthesis was studied in cultured smooth muscle cells from pig aorta blocked in the G0 phase by serum deprivation. Insulin enhanced [35S]sulfate incorporation into cell layer and medium-secreted proteoglycans. The increase in incorporation of the precursor was not due to a mitogenic response by smooth muscle cells to the hormone and the specific radioactivity of proteoglycans showed that the stimulation reflected a real increase in sulfated proteoglycan synthesis. Maximal stimulation was observed, for the cell layer as well as for the medium, 40 h after the addition of 1.7 x 10(-7) M insulin and reached respectively 65 and 53%. This stimulation was about 80 and 60% of the level achieved with 10% fetal calf serum for cell layer and medium-secreted proteoglycans, respectively. The half-maximal effect was attained, for both the cell layer and the medium, in the presence of 2.1 x 10(-9) M insulin. Proteoglycans secreted into the medium, in the presence of 1.7 x 10(-8) M insulin for 40 h, showed a higher proportion of complexes (24%) than those synthesized in control medium (11%) and at least 95% of the monomers from culture treated with insulin were characterized by a smaller hydrodynamic size than those synthesized by cells maintained in control medium. This decrease in the size of proteoglycans was partly due to a decrease in the size of their glycanic chains.
authors.affiliation: Laboratoire de Biochimie, INSERM-U. 181, Faculté de Médecine, Saint-Antoine, Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: Breton
authors.forename: E
authors.initials: E
authors.lastname: Berrou
authors.forename: E
authors.initials: E
authors.lastname: Deudon
authors.forename: M C
authors.initials: MC
authors.lastname: Brahimi-Horn
authors.forename: J
authors.initials: J
authors.lastname: Picard
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000378:metabolism; D002478:Cells, Cultured; D002845:Chromatography; D006025:Glycosaminoglycans / Q000096:biosynthesis; D007328:Insulin / Q000494:pharmacology*; D007399:Interphase; D008970:Molecular Weight; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism*; D011509:Proteoglycans / Q000096:biosynthesis*; D013431:Sulfates / Q000378:metabolism; D013552:Swine
chemical_list: D006025:Glycosaminoglycans; D007328:Insulin; D011509:Proteoglycans; D013431:Sulfates; C013786:A73025