title: Regulation of fibrillar collagen types I and III and basement membrane type IV collagen gene expression in pressure overloaded rat myocardium.
abstract: Left ventricular hypertrophy is based on cardiac myocyte growth. The hypertrophic process can be considered heterogeneous based on whether it also includes a remodeling and accumulation of fibrillar types I and III collagens that are responsible for impaired myocardial stiffness. In the heart, the messenger RNA (mRNA) for fibrillar collagen types I and III has been detected only in cardiac fibroblasts, whereas mRNA for basement membrane collagen type IV is present in both fibroblasts and myocytes. We studied the early and long-term expression of these collagenous proteins in rat myocardium after abdominal aortic banding with renal ischemia. Complementary DNA probes for rat pro-alpha 2 (I), mouse type III and mouse type IV collagens, and chicken beta-actin were used. Northern and dot blot analysis on total RNA extracted from left ventricular tissue indicated a sixfold increase in steady-state levels of mRNA for collagen type I on day 3 of abdominal aortic banding, which had declined to control levels by day 7 where it remained rather constant at 4 and 8 weeks. Type III collagen showed a similar pattern of gene expression after banding. mRNA levels for type IV collagen, on the other hand, were elevated on day 1 after banding, returning to control at day 7 and remaining constant. Actin mRNA levels also increased on day 1 of banding, followed by a rapid return to control levels. Monospecific antibody to types I and III collagens and immunofluorescent light microscopy on frozen sections of the myocardium revealed that at 1 week after banding, the distribution and density of these collagens were similar to those of control animals.(ABSTRACT TRUNCATED AT 250 WORDS)
authors: Cardiovascular Institute, Michael Reese Hospital, University of Chicago Pritzker School of Medicine, Ill 60616.
authors: D
authors: D
authors: Chapman
authors: K T
authors: KT
authors: Weber
authors: M
authors: M
authors: Eghbali
mesh_terms: D000199:Actins / Q000235:genetics; D000818:Animals; D001012:Aorta, Abdominal; D001485:Basement Membrane / Q000378:metabolism*; D006332:Cardiomegaly / Q000209:etiology / Q000378:metabolism*; D003094:Collagen / Q000235:genetics*; D003250:Constriction; D015342:DNA Probes; D005347:Fibroblasts / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D006973:Hypertension / Q000150:complications; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D009210:Myofibrils / Q000378:metabolism*; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000199:Actins; D015342:DNA Probes; D012333:RNA, Messenger; D003094:Collagen