par Owen, Ann;Vandermeers, André 
;Malaisse, Willy
Référence IRCS Medical Science, 9, page (468-469)
Publication Publié, 1981
;Malaisse, Willy Référence IRCS Medical Science, 9, page (468-469)
Publication Publié, 1981
Article révisé par les pairs
| Résumé : | Ca- and Mg-ATPase activity was measured in crude homogenates and in a subcellular particulate fraction from rat kidney cortex. Increasing concentrations of either Ca2+ or Mg2+ caused a dose-related increase in ATPase activity. Bovine pancreatic calmodulin (1 μM) increased Ca-ATPase activity, but failed to affect Mg-ATPase activity. In relative terms, the calmodulin-induced increment in Ca-ATPase activity was most marked at low Ca2+ concentration. Thus, the calmodulin-induced increment in reaction velocity, relative to the paired control value, averaged 100.5 ± 22.5, 23.2 ± 3.4 and 11.8 ± 1.0 per cent in the presence of 0.13 μM, 15 μM and 0.22 mM Ca2+ respectively. This pattern is similar to that characterizing the effect of calmodulin on Ca-ATPase in human red cells. The activation of kidney cortex Ca-ATPase by calmodulin, which is present in kidney cells, may participate in the regulation of Ca2+ handling by these cells. |
