Changes in skeletal muscle biochemistry and histology relative to fiber type in rats with heart failure

• Published in: Journal of applied physiology (1985) 1997-10, Vol.83 (4), p.1291-1299
• Main Authors: Delp, Michael D, Duan, Changping, Mattson, John P, Musch, Timothy I
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Body Weight - physiology; Cardiology. Vascular system; Citrate (si)-Synthase - metabolism; Female; Heart; Heart Failure - enzymology; Heart Failure - metabolism; Heart Failure - pathology; Heart failure, cardiogenic pulmonary edema, cardiac enlargement; Hemodynamics - physiology; Histocytochemistry; Life Sciences (General); Medical sciences; Mitochondria, Heart - enzymology; Mitochondria, Heart - metabolism; Mitochondria, Heart - ultrastructure; Muscle Fibers, Fast-Twitch - enzymology; Muscle Fibers, Fast-Twitch - metabolism; Muscle Fibers, Fast-Twitch - pathology; Muscle Fibers, Slow-Twitch - enzymology; Muscle Fibers, Slow-Twitch - metabolism; Muscle Fibers, Slow-Twitch - pathology; Muscle, Skeletal - enzymology; Muscle, Skeletal - metabolism; Muscle, Skeletal - pathology; Muscular Atrophy - metabolism; Muscular Atrophy - pathology; Organ Size - physiology; Phosphofructokinase-1 - metabolism; Rats; Rats, Wistar; Space life sciences; Ventricular Dysfunction, Left - enzymology; Ventricular Dysfunction, Left - metabolism; Ventricular Dysfunction, Left - pathology
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/jappl.1997.83.4.1291

Michael D. Delp, Changping Duan, John P. Mattson, and Timothy I. Musch Departments of Health and Kinesiology and of Medical Physiology, Texas A&M University, College Station, Texas 77843; Department of Surgery, Allegheny University of the Health Sciences, Pittsburgh, Pennsylvania 15212; and Departments of Anatomy and Physiology and of Kinesiology, Kansas State University, Manhattan, Kansas 66506 Received 11 December 1996; accepted in final form 19 May 1997. Delp, Michael D., Changping Duan, John P. Mattson, and Timothy I. Musch. Changes in skeletal muscle biochemistry and histology relative to fiber type in rats with heart failure. J. Appl. Physiol. 83(4): 1291-1299, 1997. One of the primary consequences of left ventricular dysfunction (LVD) after myocardial infarction is a decrement in exercise capacity. Several factors have been hypothesized to account for this decrement, including alterations in skeletal muscle metabolism and aerobic capacity. The purpose of this study was to determine whether LVD-induced alterations in skeletal muscle enzyme activities, fiber composition, and fiber size are 1 ) generalized in muscles or specific to muscles composed primarily of a given fiber type and 2 ) related to the severity of the LVD. Female Wistar rats were divided into three groups: sham-operated controls ( n  = 13) and rats with moderate ( n  = 10) and severe ( n  = 7) LVD. LVD was surgically induced by ligating the left main coronary artery and resulted in elevations ( P  < 0.05) in left ventricular end-diastolic pressure (sham, 5 ± 1 mmHg; moderate LVD, 11 ± 1 mmHg; severe LVD, 25 ± 1 mmHg). Moderate LVD decreased the activities of phosphofructokinase (PFK) and citrate synthase in one muscle composed of type IIB fibers but did not modify fiber composition or size of any muscle studied. However, severe LVD diminished the activity of enzymes involved in terminal and -oxidation in muscles composed primarily of type I fibers, type IIA fibers, and type IIB fibers. In addition, severe LVD induced a reduction in the activity of PFK in type IIB muscle, a 10% reduction in the percentage of type IID/X fibers, and a corresponding increase in the portion of type IIB fibers. Atrophy of type I fibers, type IIA fibers, and/or type IIB fibers occurred in soleus and plantaris muscles of rats with severe LVD. These data indicate that rats with severe LVD after myocardial infarction exhibit 1 ) decrements in mitochondrial enzyme activities independent of muscle fiber compositio