Ketzer Luisa Andrea, de Meis Leopoldo
Instituto de Bioquímica Médica, Prédio do CCS, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, RJ 21941-590, Brazil.
Biochem Biophys Res Commun. 2008 Apr 25;369(1):265-9. doi: 10.1016/j.bbrc.2007.12.182. Epub 2008 Jan 15.
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.
