Immunohistochemistry with semiquantitative image analysis showed that prolactin receptor in distal renal tubules of female rats is most sensitive to the negative effects of both cholestasis and hyperprolactinemia. The responses of medullary tubules to cholestasis and hyperprolactinemia were less pronounced: decrease and increase in prolactin receptor expression, respectively. Proximal tubules were characterized by stable levels of prolactin receptor expression insensitive to the effects of obstructive cholestasis and hyperprolactinemia. The cholestasis-induced changes in the intensity of prolactin receptor expression were opposite in kidney and liver cells. It is concluded that different parts of the nephron differ by the presence, type, and direction of regulation of prolactin receptor expression in obstructive cholestasis and hyperprolactinemia.