OXIDATIVE STRESS IS INVOLVED IN THE IMPAIR- MENT OF MRP2 ACTIVITY INDUCED BY ESTRADIOL 17ß-D-GLUCURONIDE IN RAT HEPATOCYTES.

SALAS, GIMENA; MEDEOT, ANABELA C.; SCHUCK, VIRGINIA S.; MISZCZUK, GISEL S.; ANDERMATTEN, ROMINA B.; CIRIACI, NADIA; RAZORI, MARIA VALERIA; SANCHEZ POZZI, ENRIQUE J.; ROMA, MARCELO G.; BASIGLIO, CECILIA L.; CROCENZI, FERNANDO A.

Mar del Plata

Congreso; Reunión Anual de la SAIC; 2020

Sociedad Argentina de Investigación Clínica

Estradiol 17β-d-glucuronide (E17G) is an endogenous metabolite of estradiol which mediates the intrahepatic cholestasis of pregnancy. E17G impairs canalicular secretion via several kinase-mediated signaling pathways which leads to endocytosis and intracellular retention of canalicular transporters, contributing the MEK-ERK1/2 pathway to the second process. Oxidative stress has also been shown to trigger these effects on canalicular transporters. We studied the possible role of oxidative stress in E17G-induced impairment of Mrp2 function by assessing the canalicular vacuolar accumulation (cVA) of glutathione-S-methylfluorescein (GS-MF) in rat hepatocyte couplets (RHC). The possible E17G-induced increase in intracellular reactive oxygen species (ROS) was assessed fluorometrically in primary cultured rat hepatocytes (PCH) by the 2',7'-dichloro-fluorescin-diacetate (DCFH-DA) assay. A probable role of ROS in E17G-induced Mrp2 function impairment was evaluated by preincubating RHC for 15 min with the antioxidants vitamin C (VitC), mannitol (Man), N,N?-diphenyl-p-phenylenediamine (DPPD), and also with apocynin (Apo), a specific inhibitor of the ROS-producing enzyme NADPH oxidase (NOX), prior to a 20-min exposure to E17G; a potential role of MEK-ERK1/2 pathway was assessed by its inhibition with the MEK inhibitor PD98059 (PD). E17G increased intracellular ROS by 43±9 %[p