This study examined the role of a P2 receptor and arachidonic acid (AA) in regulatory volume decrease (RVD) by American alligator red blood cells (RBCs). Osmotic fragility was determined optically, mean cell volume was measured by electronic sizing, and changes in intracellular Ca(2+) concentration were visualized using fluorescence microscopy. Gadolinium (50 μM), hexokinase (2.
View Article and Find Full Text PDFFish Physiol Biochem
December 2011
The purpose of this study was to examine regulatory volume decrease (RVD) in Atlantic salmon red blood cells (RBCs). Osmotic fragility was determined optically, mean cell volume was measured electronically, and changes in intracellular Ca(2+) concentration were visualized using fluorescence microscopy and fluo-4-AM. Cells displayed an increase in osmotic fragility and an inhibition of volume recovery following hypotonic shock when they were exposed to a high taurine Ringer or when placed in a high K(+) medium.
View Article and Find Full Text PDFThe American alligator can hibernate during winter, which may lead to osmotic imbalance because of reduced kidney function and lack of food consumption during this period. Accordingly, we hypothesized that their red blood cells would have a well-developed regulatory volume decrease (RVD) to cope with the homeostatic challenges associated with torpor. Osmotic fragility was determined optically, mean cell volume was measured by electronic sizing, and changes in intracellular Ca²+ concentration were visualized using fluorescence microscopy and fluo-4-AM.
View Article and Find Full Text PDFThis study examined the role of Ca(2+) in regulatory volume decrease by Necturus erythrocytes. Hypotonic shock (50% tonicity) stimulated an increase in cytosolic free Ca(2+), detected using epi-fluorescence microscopy and the fluorescent Ca(2+) indicator fluo-4-AM (10 microM). A similar increase in fluorescence did not occur under isosmotic conditions, unless cells were exposed to the Ca(2+) ionophore A23187 (0.
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