September 1, 1984AJP Cell Physiology
Amiloride-sensitive Na+-H+ exchange in platelets and leukocytes: detection by electronic cell sizing
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Discussion
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Implication
Experimental study demonstrates amiloride-sensitive sodium-hydrogen exchange in human platelets and leukocytes, indicating the transporter's ubiquitous presence.
Key Points
- To develop an electronic cell sizing technique to detect Na+-H+ antiport activity via osmotic swelling and evaluate its presence in mammalian blood cells.
- Suspended isolated human platelets, neutrophils, lymphocytes, monocytes, and cultured lymphoblast and macrophage cell lines in Na-propionate medium to acidify the cytoplasm.
- Monitored Na+-H+ countertransport and subsequent osmotic cell swelling using electronic sizing, alongside 22Na+ uptake assays and alkalinization measurements with and without amiloride.
- Cytoplasmic acidification triggered Na+-H+ exchange, driving intracellular Na+ accumulation, osmotic water entry, and measurable cell swelling across all tested primary and cultured blood cell types.
- Cell swelling, Na+-dependent alkalinization, and 22Na+ uptake were consistently inhibited by amiloride, confirming exchanger-dependent volume changes.
Cite This Study
Grinstein et al. (1984) studied this question.