CARDIAC COLLAGEN CHANGES DURING THE DEVELOPMENT OF RIGHT-VENTRICULAR HYPERTROPHY IN TIGHT-SKIN MICE WITH EMPHYSEMA

The tight-skin (Tsk) mouse is a genetic model of pulmonary emphysema. In this mouse, right ventricular hypertrophy (RVH) starts to develop a t approximately 8 months of age, probably as a consequence of the emph ysema. The aim of the present study was to investigate cardiac collage n synthesis, content, and types both before and during the development of RVH. Collagen synthesis, assessed by the [H-3]proline incorporatio n method, was significantly increased in the right ventricle of 3-mont h-old Tsk mice. This was accompanied by a marked increase in right ven tricle collagen content. Collagen typing showed no difference from con trols. At 8 months of age collagen synthesis had returned to control V alues, right Ventricular collagen content was elevated but held lower values than at 3 months, and collagen typing showed a prevalence of th e more compliant type III. By 16 months of age, right Ventricular coll agen content had returned to control values and there was a shift in c ollagen types due to a relative increase of the more rigid type I. At 24 months of age right Ventricular collagen content was increased agai n and collagen type I continued to predominate. These results suggest a dynamic role for collagen both before and during the development of RVH secondary to emphysema. (C) 1994 Academic Press, Inc.