Localization of authentic thromboxane A2/prostaglandin H2 receptor in the rat kidney.

Using a polyclonal antibody against authentic thromboxane A2/prostaglandin H2 (TxA2/PGH2) receptor protein, we assessed the distribution of this receptor in the normal rat kidney by routine methods of immunofluorescence microscopy. The receptor localized both in glomeruli and in tubules. In the former, the distribution of the receptor was most prominent along the lumen of glomerular capillary loops. Parietal epithelial cells of the Bowman's capsule, podocytes and mesangial cells also demonstrated immunostainable receptor. In the tubules, the receptor localized most prominently at the base of the brush border of proximal tubules and at the luminal surface of thick ascending limbs and distal convoluted tubules. These observations point to sites that are likely to be targeted by thromboxane A2 in forms of renal injury characterized by enhanced synthesis of this eicosanoid.