These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: The sarcolemmal Ca2+-ATPase of the ischemic-reperfused myocardium: protective effect of hypocalcemia on calmodulin-stimulated activity.
    Author: Samouilidou EC, Karli JN, Levis GM, Darsinos JT.
    Journal: Life Sci; 1998; 62(1):29-36. PubMed ID: 9444965.
    Abstract:
    This study was designed to examine the role of calcium in the ischemia-induced changes of calmodulin-stimulated Ca2+-ATPase activity of heart sarcolemma of dogs subjected to coronary artery ligation (90 min) and reperfusion (30 min). This was attained by the application of systemic hemodialysis with low Ca2+ dialysate in six dogs (group A) and the comparison of the results with those obtained from animals subjected to normal Ca2+ hemodialysis (control group B, n=7). A very significant (p<0.001) decrease was found in the calmodulin-stimulated Ca2+-ATPase activity measured in the ischemic and non-ischemic parts of group B. This was associated with a decrease in the maximal velocity (v(max)) of the reaction of stimulation and an increase in the apparent Km for calmodulin. The kinetics of the calmodulin-stimulated Ca2+-ATPase also assessed in the presence of trifluoroperazine, a specific inhibitor for calmodulin binding, showed that the affinity for calmodulin was higher in the ischemic part of group A than of B, while v(max) was not substantially different. The above data may suggest that the inhibition of the calmodulin-stimulated Ca2+-ATPase produced by ischemia-reperfusion and its preservation under low Ca2+, are exerted at the calmodulin-binding site of the enzyme.
    [Abstract] [Full Text] [Related] [New Search]