RUI: Signal Transduction During Regulatory Volume Decrease in Necturus Erythrocytes

Ripon College, Ripon WI

Investigators

Abstract

Recently there has been a growing body of evidence indicating ATP plays a significant role as an extracellular messenger in a number of biological processes, including cell volume regulation. Extracellular ATP exerts its influence by acting as an autocrine/paracrine signal, binding to specific cell surface receptors known as purinoceptors. Purinoceptors have been subdivided into two main categories: P1 receptors that recognize nucleosides, such as adenosine, and P2 receptors that bind ATP and other nucleotides. The P2 receptors have been further subdivided into two main subtypes: P2X (ligand-gated ion channels) and P2Y (receptors coupled to a G-protein). Initial studies have shown that RVD in Necturus red blood cells (RBCs) depends on K+ efflux through an ion channel that is activated during cell swelling by extracellular ATP (Light et al., Am. J. Physiol., 277 (Cell Physiol. 46): C480-C491, 1999). The objective of this project is to identify the purinoceptor used by Necturus RBCs to regulate cell volume in hypotonic solutions