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Myostatin gene knockout increases vascular function in skeletal and cardiac muscle tissues
Author(s) -
Ali Mohammed Irfan,
Mintz James D,
Elms Shawn,
Hamrick Mark W,
Stepp David W
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.949.2
Subject(s) - medicine , endocrinology , myostatin , skeletal muscle , microcirculation , vascular smooth muscle , vascular resistance , blood pressure , mesenteric arteries , vasodilation , myogenic contraction , chemistry , artery , smooth muscle
Exercise improves vascular health through mechanisms yet to be defined. Exercise enhances both muscle mass and metabolism, in part by decreasing myostatin (MS). Genetic MS deletion increases muscle mass and metabolism but vascular effects of these changes are unknown. This study tested the hypothesis that MS deletion would alter vascular function in the microcirculation. To test this hypothesis, we compared Ms −/− mice on an ICR background with Ms +/+ ICR as controls. Gracilis (SA), coronary (CA), gonadal (GA) and mesenteric (MA) resistance arteries were analyzed in vitro (±Ca 2+ , i.d. < 150μm). Acetylcholine (ACh) reactivity was used to assess endothelial relaxation. Similarity was seen between Ms −/− and Ms +/+ in mean arterial pressure (90±9 vs. 90±10 mmHg), heart rate (600±136 vs. 545±93 bpm) but in Ms −/− visceral adiposity and plasma leptin (2.4±0.3 vs. 0.6±0.1 ng/ml, p<0.01) were reduced. Maximum passive i.d. was similar in both strains in all arteries. In Ms −/− , dilation to ACh was increased in SA (88±1 vs. 71±4%, p<0.01) and CA (63±2 vs. 51±4%, p<0.01), unchanged in GA and reduced in MA (45±2 vs. 63±4%, p<0.01). Myogenic tone was reduced in CA and SA but unchanged in MA or GA. Taken together, these data indicate that increased muscle mass has pro‐dilatory effects on the microcirculation of muscular organs. These findings may explain, in part, improvements in vascular health seen with exercise training.HL76533