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: Agonist-evoked alkaline shift in the cytosolic pH set point for activation of Na+/H+ antiport in human platelets. The role of cytosolic Ca2+ and protein kinase C.
    Author: Kimura M, Gardner JP, Aviv A.
    Journal: J Biol Chem; 1990 Dec 05; 265(34):21068-74. PubMed ID: 2174433.
    Abstract:
    This work examines the roles of elevated cytosolic Ca2+ and stimulation of protein kinase C in agonist and non-agonist-mediated alkaline shift of the cytosolic pH set point for activation of Na+/H+ antiport in human platelets. Ca2(+)-depleted and control platelets were subjected to phorbol 12-myristate 13-acetate, thrombin, vasopressin, and ionomycin in 1 mM or Ca2+ free, nominally bicarbonate free media. To measure the cytosolic pH set point for Na+/H+ antiport activation, cells were acidified to different levels using the sodium propionate method. In some experiments protein kinase C was inhibited by staurosporine. Both protein kinase C stimulation and elevation of cytosolic Ca2+ can produce an alkaline shift in the pH set point for activation of Na+/H+ antiport in human platelets. However, the effect of Ca2+i on the pH set point predominates that of protein kinase C stimulation. Cytosolic Ca2+ is a prerequisite for agonist-evoked alkaline shift in the cytosolic pH set point for activation of Na+/H+ antiport. The cytosolic Ca2+ level is also essential for maintaining the basal cytosolic pH. These findings underscore the central role of cytosolic Ca2+ under basal and stimulated states in regulating cytosolic pH of human platelets.
    [Abstract] [Full Text] [Related] [New Search]