The cortical thick ascending limb and early distal convoluted tubule in the urinary concentrating mechanism

Abstract

This chapter reviews the process of dilution of tubule fluid by the cortical thick ascending limb of the loop of Henle and by the early distal convoluted tubule. After a description of the cellular mechanisms involved, the factors (peritubular as well as luminal) that modulate the rate of NaCl reabsorption are discussed. Next, the interplay of the cortical thick ascending limb and early distal tubule and their contribution to the urinary concentrating mechanism will be summarized. Complex aspects, such as the function of the two nephron segments in situ and under a variety of conditions, are beyond the scope of this article and will be covered in part by other contributors to this symposium.