Heat production by skeletal muscles of rats and rabbits and utilization of glucose 6-phosphate as ATP regenerative system by rats and rabbits heart Ca2+-ATPase.
This report is divided in two parts. The first section shows that vesicles derived from the sarcoplasmic reticulum of rats skeletal muscle can cleave ATP at a faster rate and produce more heat that the vesicles derived from rabbit skeletal muscle. In the second part, we compared the rates of Ca(2+) transport and ATP hydrolysis by rats and rabbits heart sarcoplasmic reticulum. It is shown that the two vesicles preparations are able to use glucose 6-phosphate and hexokinase as an ATP regenerative system. The rates of Ca(2+)-uptake and ATP hydrolysis measured with glucose 6-phosphate and hexokinase is four to six times slower than that measured with phosphoenolpyruvate and pyruvate kinase as ATP regenerative system.
Ketzer
Luisa Andrea
LA
Instituto de Bioquímica Médica, Prédio do CCS, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, RJ 21941-590, Brazil.
de Meis
Leopoldo
L
D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D002478:Cells, Cultured; D004734:Energy Metabolism / Q000502:physiology*; D019298:Glucose-6-Phosphate / Q000378:metabolism*; D066298:In Vitro Techniques; D018482:Muscle, Skeletal / Q000502:physiology*; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D012519:Sarcoplasmic Reticulum / Q000502:physiology*; D022722:Thermogenesis / Q000502:physiology*
D019298:Glucose-6-Phosphate; D000255:Adenosine Triphosphate; D000252:Calcium-Transporting ATPases