Using immunohistochemical method with semiquantitative analysis of images, we showed that mrp2 expression in response to cholestasis decreased in hepatocytes and cholangiocytes, and remained unchanged in the kidney structures. A decrease of mrp2 expression in renal tubules leading to a decrease of metabolic intoxication of the kidney was demonstrated in cholestasis of pregnancy model. In bile ducts cells, negative correlations of mrp2 with previously measured levels of prolactin receptors, CFTR, and mrp3 were revealed. In renal structures and in hepatocytes, no correlations were found between the expression of these proteins. We hypothesize that prolactin produces a direct effect on mrp2 expression in bile ducts cells mediated by prolactin receptors in cholangiocytes. The absence of correlations between mrp2 and the above-mentioned proteins in hepatocytes and renal structures is most likely related to prolactin effects on other systemic regulators.