Effect of myotonia induced by anthracene-9-carboxylic acid on mitochondrial calcium, plasma creatinine-phosphokinase and aldolase activity in the rat.
The frequent association of myotonia with dystrophy and the knowledge that calcium is increased in injured skeletal muscle cells suggest a possible relationship between cell calcium and myotonic alterations. This investigation has been performed to study the role of calcium in experimental myotonia induced by anthracene-9-carboxylic acid (9-AC) in rats treated with several regimens of food and exercise. Thirty-two rats were divided into 4 groups of 8 rats each, one control and 3 experimental groups. The treatments included caffeine plus exercise (group 2), and a calcium-rich diet (group 3); these procedures were designed to increase intracellular calcium; another group was treated with 9-AC as a myotonia-inducer (group 4). The treatment for all groups lasted 60 days. No significant differences in plasma sodium, potassium, chloride and calcium between control and experimental groups were observed. Whole muscle calcium in wet tissue samples did no change with any treatment. On the contrary, mitochondrial calcium showed a significantly higher concentration in group 3 and 4. CPK and aldolase activities in groups 1, 2 and 3 were similar; but in group 4 these enzyme activities were significantly higher (p less than 0.05). The electrical and mechanical responses were not altered in any rat with any experimental treatment. Our data suggest that myotonia is a predisposing factor for an altered mitochondrial calcium homeostasis in this model; in addition, the enzyme activities of CPK and aldolase were increased in the rats of group 4 implicating that myotonia is a crucial factor in the development of enzymatic abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)
Villegas-Navarro
A
A
Autonomous University of Nuevo León, Monterrey, México.
Bustos
E
E
González
A
A
Salazar
S
S
Jiménez
Z
Z
Solis
J G
JG
Mercado
R
R
González
G
G
Reyes
J L
JL
Dieck
T A
TA
D000818:Animals; D000873:Anthracenes; D002118:Calcium / Q000378:metabolism* / Q000502:physiology; D003402:Creatine Kinase / Q000097:blood*; D004032:Diet; D005634:Fructose-Bisphosphate Aldolase / Q000097:blood*; D008297:Male; D008931:Mitochondria, Muscle / Q000378:metabolism*; D009222:Myotonia / Q000139:chemically induced / Q000201:enzymology / Q000378:metabolism*; D005082:Physical Exertion / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley
D000873:Anthracenes; C010030:9-anthroic acid; D003402:Creatine Kinase; D005634:Fructose-Bisphosphate Aldolase; D002118:Calcium