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Beta-adrenergic receptor distribution among muscle fiber types and resistance arterioles of white, red, and intermediate skeletal muscle.
Circ Res. 1989 Jun; 64(6):1096-105.CircR

Abstract

The pathophysiological effects of congestive heart failure and physiological effects of exercise training on skeletal muscle may be mediated in part by modulation of beta-adrenergic receptor density. To shed light on the physiological role of skeletal muscle beta-receptors, their density and distribution were characterized in muscle fibers and resistance arterioles of whole tissue slices of three rat hindquarter muscles differing markedly in fiber type composition and capacities for oxidative metabolism and vasodilatation. Binding isotherms and quantitative light microscopic autoradiographic localization of receptors were performed by incubating tissue slices in selected concentrations of [125I]cyanopindolol with and without 10(-5) M l-propranolol. Muscle fiber types were delineated in adjacent sections by histochemical staining of myofibrillar ATPase activity at pH 4.5-4.55. The total tissue content of receptors (Bmax) was nearly threefold greater in the soleus, a muscle consisting almost entirely of slow-twitch (type I) fibers than in superficial white vastus lateralis, a muscle composed of greater than 95% fast-twitch (type IIb) fibers. Bmax was intermediate in gastrocnemius, a mixed fiber muscle (all differences p less than 0.01). Receptor affinity for radioligand was higher in the white vastus than in the mixed fiber and slow-twitch muscles (Kd = 3.5 +/- 0.4 pM for white vastus versus 6.8 +/- 0.8 and 6.4 +/- 1.1 pM in gastrocnemius and soleus, respectively; both p less than 0.01 versus white vastus). Disparities in Bmax among muscles were due entirely to differences in receptor densities of skeletal muscle cells as shown autoradiographically. Furthermore, variations in Bmax of the three skeletal muscles were directly related to percentage of type I fibers (r = 0.99; p less than 0.001), which had a beta-receptor density that was approximately 4.5-fold greater than in superficially located type IIb fibers, 3.2-fold greater than in intermediate depth type IIb fibers, and 2.0-fold greater than in type IIa fibers. In contrast, grain densities of resistance arterioles were similar regardless of surrounding skeletal muscle fiber type composition. However, resistance arterioles were 2.5- and 6.1-fold more numerous in the slow-twitch soleus than in the gastrocnemius and superficial white vastus, respectively (all differences p less than 0.01). We conclude that beta-receptor density of rat hindquarter skeletal muscles is directly proportional to percentage of slow-twitch fibers, while receptor affinity for antagonist is higher in fast-twitch than in slow-twitch or mixed fiber muscles.(

ABSTRACT

TRUNCATED AT 250 WORDS)

Authors+Show Affiliations

Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110.No affiliation info availableNo affiliation info available

Pub Type(s)

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

Language

eng

PubMed ID

2541942

Citation

Martin, W H., et al. "Beta-adrenergic Receptor Distribution Among Muscle Fiber Types and Resistance Arterioles of White, Red, and Intermediate Skeletal Muscle." Circulation Research, vol. 64, no. 6, 1989, pp. 1096-105.
Martin WH, Murphree SS, Saffitz JE. Beta-adrenergic receptor distribution among muscle fiber types and resistance arterioles of white, red, and intermediate skeletal muscle. Circ Res. 1989;64(6):1096-105.
Martin, W. H., Murphree, S. S., & Saffitz, J. E. (1989). Beta-adrenergic receptor distribution among muscle fiber types and resistance arterioles of white, red, and intermediate skeletal muscle. Circulation Research, 64(6), 1096-105.
Martin WH, Murphree SS, Saffitz JE. Beta-adrenergic Receptor Distribution Among Muscle Fiber Types and Resistance Arterioles of White, Red, and Intermediate Skeletal Muscle. Circ Res. 1989;64(6):1096-105. PubMed PMID: 2541942.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Beta-adrenergic receptor distribution among muscle fiber types and resistance arterioles of white, red, and intermediate skeletal muscle. AU - Martin,W H,3rd AU - Murphree,S S, AU - Saffitz,J E, PY - 1989/6/1/pubmed PY - 1989/6/1/medline PY - 1989/6/1/entrez SP - 1096 EP - 105 JF - Circulation research JO - Circ Res VL - 64 IS - 6 N2 - The pathophysiological effects of congestive heart failure and physiological effects of exercise training on skeletal muscle may be mediated in part by modulation of beta-adrenergic receptor density. To shed light on the physiological role of skeletal muscle beta-receptors, their density and distribution were characterized in muscle fibers and resistance arterioles of whole tissue slices of three rat hindquarter muscles differing markedly in fiber type composition and capacities for oxidative metabolism and vasodilatation. Binding isotherms and quantitative light microscopic autoradiographic localization of receptors were performed by incubating tissue slices in selected concentrations of [125I]cyanopindolol with and without 10(-5) M l-propranolol. Muscle fiber types were delineated in adjacent sections by histochemical staining of myofibrillar ATPase activity at pH 4.5-4.55. The total tissue content of receptors (Bmax) was nearly threefold greater in the soleus, a muscle consisting almost entirely of slow-twitch (type I) fibers than in superficial white vastus lateralis, a muscle composed of greater than 95% fast-twitch (type IIb) fibers. Bmax was intermediate in gastrocnemius, a mixed fiber muscle (all differences p less than 0.01). Receptor affinity for radioligand was higher in the white vastus than in the mixed fiber and slow-twitch muscles (Kd = 3.5 +/- 0.4 pM for white vastus versus 6.8 +/- 0.8 and 6.4 +/- 1.1 pM in gastrocnemius and soleus, respectively; both p less than 0.01 versus white vastus). Disparities in Bmax among muscles were due entirely to differences in receptor densities of skeletal muscle cells as shown autoradiographically. Furthermore, variations in Bmax of the three skeletal muscles were directly related to percentage of type I fibers (r = 0.99; p less than 0.001), which had a beta-receptor density that was approximately 4.5-fold greater than in superficially located type IIb fibers, 3.2-fold greater than in intermediate depth type IIb fibers, and 2.0-fold greater than in type IIa fibers. In contrast, grain densities of resistance arterioles were similar regardless of surrounding skeletal muscle fiber type composition. However, resistance arterioles were 2.5- and 6.1-fold more numerous in the slow-twitch soleus than in the gastrocnemius and superficial white vastus, respectively (all differences p less than 0.01). We conclude that beta-receptor density of rat hindquarter skeletal muscles is directly proportional to percentage of slow-twitch fibers, while receptor affinity for antagonist is higher in fast-twitch than in slow-twitch or mixed fiber muscles.(ABSTRACT TRUNCATED AT 250 WORDS) SN - 0009-7330 UR - https://www.unboundmedicine.com/medline/citation/2541942/Beta_adrenergic_receptor_distribution_among_muscle_fiber_types_and_resistance_arterioles_of_white_red_and_intermediate_skeletal_muscle_ L2 - https://www.ahajournals.org/doi/10.1161/01.res.64.6.1096?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -