In vertebrates, the distal nephron of the kidney is the important site for the regulation of the levels of plasma sodium and potassium. In mammals, it is the site of reabsorption of sodium and secretion of potassium in the presence of pumps while in amphibia; passive mechanisms appear to be the means of control. However, upon exposure of amphibian distal nephrons to potassium containing media, an increase in the number of maxi-channels was observed. This is called potassium-adaptation. The primary goal of this research is to examine how do distal nephron cells independently regulate cell volume and the need to secrete potassium into the urine to maintain homeostasis. A molecular approach will be taken. This research will greatly enhance our understanding of pot tation and related mechanism.
