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: Global ischemia increases the density of voltage-dependent calcium channels in porcine cardiac sarcolemma.
    Author: Blanck TJ, Yasukochi S, Quigg M, Curtis WE, Gardner TJ.
    Journal: Anesth Analg; 1997 May; 84(5):972-5. PubMed ID: 9141917.
    Abstract:
    The objective of this work was to determine whether normothermic global cardiac ischemia in a porcine model was associated with a change in the density (Bmax) of voltage-dependent calcium channels in myocardial sarcolemmal membranes. Pigs were anesthetized, a thoracotomy was performed, and samples were taken of the left and right ventricles from control and ischemic hearts. Dihydropyridine-binding sites were quantified using [3H]isradipine, and 5'-nucleotidase activity was measured by the liberation of inorganic phosphate from adenosine monophosphate. Bmax and dissociation constants and 5'-nucleotidase activity for control and ischemic tissues, respectively, were compared by using Student's t-test for unpaired samples. After normothermic global ischemia, the Bmax of [3H]isradipine binding increased in the left ventricle by 81% (299% +/- 1.7% to 540% +/- 11% fmoles/mg, P < 0.01) and in the right ventricle by 33% (387% +/- 9.9% to 515% +/- 38% fmoles/mg, P < 0.01) compared with control. 5'-nucleotidase activity increased by 48% in the left ventricle and by 96% in the right ventricle (p < 0.05). Fifteen minutes of normothermic ischemia in the pig is associated with marked sarcolemmal abnormalities, including increases in specific dihydropyridine binding and 5'-nucleotidase activity, which reflect global changes in membrane function, which might contribute to the increase in myoplasmic calcium during ischemia.
    [Abstract] [Full Text] [Related] [New Search]