The prolactin releasing hormone receptor PRLHR also named PrRP receptor is a G-protein coupled receptor that binds the prolactin releasing hormone. RT-PCR analysis showed expression of PRLHR in the human brain, pituitaries, normal portions of adrenal glands and various tumor tissues. Northern blot analysis showed high expression of PRLHR only in tumor tissues of pheochromocytomas, indicating that PRLHR expression is high in pheochromocytomas. The present study has shown that PRLHR mRNA was widely expressed in the brain tissues, pituitaries, adrenal glands and various tumors. The high expression of PRLHR receptor in pheochromocytomas suggests potential pathophysiological roles of PRLHR in these tumors