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Changes in skeletal muscle biochemistry and histology relative to fiber type in rats with heart failure.
J Appl Physiol (1985). 1997 Oct; 83(4):1291-9.JA

Abstract

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 beta-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 composition, 2) a reduction in PFK activity in type IIB muscle, 3) transformation of type IID/X to type IIB fibers, and 4) atrophy of type I, IIA, and IIB fibers.

Authors+Show Affiliations

Department of Health and Kinesiology, Texas A&M University, College Station, Texas 77843, USA.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

9338439

Citation

Delp, M D., et al. "Changes in Skeletal Muscle Biochemistry and Histology Relative to Fiber Type in Rats With Heart Failure." Journal of Applied Physiology (Bethesda, Md. : 1985), vol. 83, no. 4, 1997, pp. 1291-9.
Delp MD, Duan C, Mattson JP, et al. Changes in skeletal muscle biochemistry and histology relative to fiber type in rats with heart failure. J Appl Physiol (1985). 1997;83(4):1291-9.
Delp, M. D., Duan, C., Mattson, J. P., & Musch, T. I. (1997). Changes in skeletal muscle biochemistry and histology relative to fiber type in rats with heart failure. Journal of Applied Physiology (Bethesda, Md. : 1985), 83(4), 1291-9.
Delp MD, et al. Changes in Skeletal Muscle Biochemistry and Histology Relative to Fiber Type in Rats With Heart Failure. J Appl Physiol (1985). 1997;83(4):1291-9. PubMed PMID: 9338439.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Changes in skeletal muscle biochemistry and histology relative to fiber type in rats with heart failure. AU - Delp,M D, AU - Duan,C, AU - Mattson,J P, AU - Musch,T I, PY - 1997/10/24/pubmed PY - 1997/10/24/medline PY - 1997/10/24/entrez KW - NASA Discipline Musculoskeletal KW - Non-NASA Center SP - 1291 EP - 9 JF - Journal of applied physiology (Bethesda, Md. : 1985) JO - J Appl Physiol (1985) VL - 83 IS - 4 N2 - 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 beta-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 composition, 2) a reduction in PFK activity in type IIB muscle, 3) transformation of type IID/X to type IIB fibers, and 4) atrophy of type I, IIA, and IIB fibers. SN - 8750-7587 UR - https://www.unboundmedicine.com/medline/citation/9338439/Changes_in_skeletal_muscle_biochemistry_and_histology_relative_to_fiber_type_in_rats_with_heart_failure_ DB - PRIME DP - Unbound Medicine ER -