Extracellular ATP stimulates volume decrease in Necturus red blood cells.

Examines whether extracellular adenosine triphosphate (ATP) stimulates regulatory volume decrease in Necturus maculosus red blood cells. Reversal of the inhibitory effect of apyrase with the nonhydrolyzable analog adenosine 5'-O-(3-thiotriphosphate); Indication that extracellular ATP stimulated cell volume decrease via a calcium-dependent step that led to potassium efflux.