Intracellular pH in human fibroblasts: effect of mitogens, A23187, and phospholipase activation
| Autor: | Leslie L. Muldoon, Robert J. Dinerstein, Mitchel L. Villereal |
|---|---|
| Rok vydání: | 1985 |
| Předmět: |
Sodium-Hydrogen Exchangers
Physiology medicine.medical_treatment Intracellular pH Phospholipase Biology Melittin chemistry.chemical_compound medicine Extracellular Humans Growth Substances Calcimycin Cells Cultured Fluorescent Dyes Growth factor Cell Biology Fibroblasts Hydrogen-Ion Concentration Fluoresceins Melitten Amiloride Enzyme Activation Sodium–hydrogen antiporter Spectrometry Fluorescence chemistry Biochemistry Phospholipases Aminoquinolines Biophysics Calcium Mitogens Carrier Proteins Intracellular medicine.drug |
| Zdroj: | American Journal of Physiology-Cell Physiology. 249:C140-C148 |
| ISSN: | 1522-1563 0363-6143 |
| DOI: | 10.1152/ajpcell.1985.249.1.c140 |
| Popis: | Serum-deprived human fibroblasts (HSWP cells) were loaded with either the fluorescent pH indicator 6-carboxy-4',5'-dimethylfluorescein or the calcium indicator quin 2, and the fluorescence of the intracellular probes was continuously monitored with a microspectrofluorometer. Addition of a cocktail of peptide growth factors causes intracellular alkalinization, which is blocked by amiloride or by replacement of extracellular Na+ with choline, confirming that mitogenic stimulation activates a Na+-H+ exchanger in HSWP cells. The exchanger is also activated by A23187, acid loading the cells, and stimulation of phospholipase activity with melittin. Growth factors and melittin activation of the exchanger have been demonstrated to be dependent on the mobilization of Ca2+ from intracellular stores. The intracellular alkalization and increase in Ca2+ activity due to both melittin and growth factors is inhibited by phospholipase inhibitors, indicating that phospholipase activity is necessary for the activation of the Na+-H+ exchanger and the mobilization of intracellular Ca2+. |
| Databáze: | OpenAIRE |
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