POLYMORPHIC EXPRESSION OF MULTIDRUG-RESISTANCE MESSENGER-RNA IN LUNG PARENCHYMA OF NONPREGNANT AND PREGNANT RATS - A COMPARISON TO CYSTIC-FIBROSIS MESSENGER-RNA EXPRESSION

Multidrug resistance (MDR1b) and cystic fibrosis transmembrane conduct ance regulator (CFTR) proteins are members of the ''ATP-binding casset te'' superfamily of transporters, They are associated with chloride ch annel activities and ATP secretion and have complementary patterns of expression in several organs, In the rat uterus, CFTR expression is re placed by MDR1b expression during pregnancy. We have studied whether e xpression of MDR1b and CFTR also vary in the lung during pregnancy, No variations in MDR1b car CFTR mRNA levels during pregnancy were detect ed, However, there was an unusual degree of variation in MDR1b mRNA ex pression in lung parenchyma between animals in both the control group and the pregnant group. If present among humans, polymorphic expressio n of MDR1 in lung parenchyma may explain part, of the differences in l ung symptomatology observed in the CF patients carrying the same mutat ion. (C) 1997 Academic Press.