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Caffeine Contractures in Denervated Frog Muscle

Overview
Journal Pflugers Arch
Specialty Physiology
Date 1984 Mar 1
PMID 6610170
Citations 1
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Abstract

Caffeine contracture tension, effect of caffeine on the resting membrane potential, and caffeine influx in normal and denervated frog sartorius muscle have been investigated. Peak caffeine contracture tension is increased after denervation at all caffeine concentrations. The percentage increases in tension are highest for lower caffeine concentrations. The caffeine concentration required for half maximum tension is decreased from about 3.6 mM in control muscles to 2.6 mM in denervated muscles. Caffeine at 3.5 mM produces a depolarization of about 6 mV in control muscles and 16mV in denervated muscles. The large contracture tensions observed in denervated muscles are not due to the greater depolarization produced by the drug in denervated muscles since innervated muscles depolarized to the same level by external K+ do not enhance caffeine contracture tension. Both control and denervated muscles are highly permeable to caffeine. The increases in sarcoplasmic reticulum development ( Moscatello et al. 1965) and calcium content ( Picken and Kirby 1976) promoted by denervation may explain the larger tension elicited by caffeine in denervated muscles.

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PMID: 7473224 PMC: 1156551. DOI: 10.1113/jphysiol.1995.sp020839.

References
1.
Foulks J, Perry F, Sanders H . Effect of external potassium concentration on caffeine contractures in frog toe muscle. Can J Physiol Pharmacol. 1971; 49(10):879-88. DOI: 10.1139/y71-123. View

2.
Kotsias B, Venosa R, Horowicz P . Denervated frog skeletal muscle. Some electrical and mechanical properties. Pflugers Arch. 1984; 400(3):262-8. DOI: 10.1007/BF00581557. View

3.
Gruener R, Stern L, Baumbach N . Caffeine-modulated acetylcholine sensitivity in denervated rat and diseased human muscle. Life Sci. 1975; 17(10):1557-65. DOI: 10.1016/0024-3205(75)90177-0. View

4.
Brown G . The actions of acetylcholine on denervated mammalian and frog's muscle. J Physiol. 1937; 89(4):438-61. PMC: 1395051. DOI: 10.1113/jphysiol.1937.sp003491. View

5.
Picken J, Kirby A . Denervated frog skeletal muscle: calcium content and kinetics of exchange. Exp Neurol. 1976; 53(1):64-70. DOI: 10.1016/0014-4886(76)90281-8. View