Remodeling of lung interstitium but not resistance vessels in canine pacing-induced heart failure

Departments of 1 Physiology and 2 Pathology, University of South Alabama, Mobile, Alabama 36688; 3 Department of Physiology, University of Bergen, Bergen, Norway; and 4 Department of Medicine, University of California, San Diego, La Jolla, California 92103 We previously showed that pacing-induced heart failure in dogs results in an enhancement of pulmonary vascular reactivity. In the present study we hypothesized that enhanced matrix deposition and structural remodeling of lung resistance microvessels would underlie these functional changes. Using biochemical measures, we found no difference in the normalized lung content of hyaluronan, uronic acid, and collagen between control dogs and dogs paced for 1 mo, although lung dry weight and noncollagen protein content increased significantly in the paced group ( P