title: Accumulation of tropoelastin by a short-term ascorbic acid treatment in the culture medium of aortic smooth muscle cells in vitro.
abstract: Treatment of cultured smooth muscle cells with ascorbic acid resulted in an accumulation of tropoelastin in the culture medium in dose-dependent and exposure time-dependent manner under the condition in which collagen synthesis was stimulated 2-fold. The steady-state level of elastin mRNA was essentially unchanged, whereas collagen mRNA content increased 2-fold by ascorbic acid treatment. Newly synthesized tropoelastin was hydroxylated in the presence of ascorbic acid but was underhydroxylated in a scorbutic condition. Short pulse experiments showed that the secretion rate of tropoelastin was unaltered by ascorbic acid treatment. Pulse-chase experiment demonstrated that the level of fully hydroxylated tropoelastin in the medium of ascorbate-treated cells was greater than that of under-hydroxylated tropoelastin. These results indicate that accumulation of tropoelastin in the medium by ascorbic acid is related to an increased stability of hydroxylated tropoelastin and/or its impaired incorporation into insoluble elastin.
authors.affiliation: Department of Dermatology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Tajima
authors.forename: H
authors.initials: H
authors.lastname: Wachi
authors.forename: A
authors.initials: A
authors.lastname: Hayashi
mesh_terms: D000199:Actins / Q000235:genetics; D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology*; D002478:Cells, Cultured; D002642:Chick Embryo; D003094:Collagen / Q000235:genetics; D003470:Culture Media; D006900:Hydroxylation; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism*; D011392:Proline / Q000737:chemistry; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014333:Tropoelastin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D000199:Actins; D003470:Culture Media; D012333:RNA, Messenger; D014333:Tropoelastin; D003094:Collagen; D011392:Proline; D001205:Ascorbic Acid