Chemical energetics of single isometric tetani in mammalian smooth muscle.
Am J Physiol
; 235(1): C1-7, 1978 Jul.
Article
em En
| MEDLINE
| ID: mdl-677300
ABSTRACT
A rabbit taenia coli preparation has been used to study the chemical energetics of smooth muscle contraction. Under the experimental conditions, the muscle had no spontaneous mechanical activity, but could be fully activated with the use of electrical field stimulation. ATP resynthesis from glycolysis and respiration was stopped with a procedure that involved treatment with metabolic inhibitors at 5 degrees C followed by rewarming to 18 degrees C. This procedure did not alter the high-energy phosphate contents of mechanical responses of the muscle. Use of this preparation to determine ATP and phosphorylcreatine changes during isometric tetani at 18 degrees C and a length of 86% LO showed that there was net ATP breakdown initially with no significant phosphorylcreatine splitting. This was followed by an increase in the rate of phosphorylcreatine splitting with net ATP synthesis. The average rate of total high-energy phosphate utilization was about 0.01 mumol/g.s for up to 60 s or about 150 times less than that of frog sartorius at the same temperature.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fosfocreatina
/
Trifosfato de Adenosina
/
Contração Muscular
/
Músculo Liso
Limite:
Animals
Idioma:
En
Ano de publicação:
1978
Tipo de documento:
Article