Localization of parathyroid hormone/parathyroid hormone-related peptide receptor mRNA in kidney.

In kidney, parathyroid hormone (PTH) exerts differential distal effects along the nephron. To define cells expressing receptors for PTH in kidney, we localized PTH/ PTH-related peptide (PTH/PTHrP) receptor mRNA in rat kidney by in situ hybridization. PTH/PTHrP receptor mRNA is localized to glomerular podocytes, convoluted and straight proximal tubules, the cortical portion of thick ascending limbs, and distal convoluted tubules, but was not detected in the thin limb of Henle's loop or in collecting ducts. Northern blot analysis showed that cultured human glomerular podocytes express a unique 4.0-kb PTH/PTHrP receptor transcript but do not express detectable levels of the common approximately 2.4-kb transcript found in whole kidney and in many other tissues. Whereas the tubular localization of PTH/PTHrP receptor mRNA coincides well with previously known sites of PTH action, the intense expression and the unique size of the PTH/PTHrP receptor transcript in glomerular podocytes suggest that PTH and/or PTHrP may play a role(s) in glomerular function.