Manifestation of Multidrug Resistance Protein 3 (MRP3) in Liver and Kidney Cells in Cholestasis: Effects of Hyperprolactinemia

Immunohistochemistry with semiquantitative image analysis showed that cholestasis induced an increase in the manifestation of mrp3 in cholangiocytes of female rats, but did not affect this parameter in the studied structures of kidney. Under conditions of normal liver function, mrp3 expression in cholangiocytes was also elevated during hyperprolactinemia. Expression of mrp3 in cholangiocytes directly correlated with prolactin receptor expression. In cholestasis, prolactin increased mrp3 manifestation of only in the distal renal tubules. Thus, mrp3 manifestation increases in liver cells, but remains unchanged in kidney cells. The hyperprolactinemia-induced changes in the mrp3 levels and their correlations with prolactin receptor expression were shown to differ in the kidney and liver cells. It was hypothesized that prolactin produced a direct effect on mrp3 expression in cholangiocytes.