The Pattern of Distribution of Selected ATP-Sensitive P2 Receptor Subtypes in Normal Rat Kidney: An Immunohistological Study

Using immunohistological techniques and available polyclonal antibodies, we have identified several ATP-sensitive P2 receptor subtypes in specific structures of the normal rat kidney. Of the P2 receptor subtypes examined, P2X₁, P2X₂ and P2Y₁ receptors were found in the smooth muscle layer of intrarenal vessels. The P2Y₁ receptor was also found on glomerular mesangial cells, the brush border membrane of the proximal straight tubule and on peritubular fibroblasts. In the cortex, P2Y₄ receptors were found on the tubule epithelium of the proximal convoluted tubule, and P2Y₂ receptors on glomerular epithelial cells (podocytes). P2X₄ and P2X₆ receptors were present throughout the renal tubule epithelium from the proximal tubule to the collecting duct. P2X₅ receptors were expressed on medullary collecting duct cells and the apical membrane of the S3 segment of the proximal tubule. Possible functions of these receptor subtypes in normal rat kidney are discussed.