Beneficial effect of spironolactone administration on ethynylestradiol-induced cholestasis in the rat: involvement of up-regulation of multidrug resistance-associated protein 2.
The effect of spironolactone (SL) administration on 17alpha-ethynylestradiol (EE)-induced cholestasis was studied, with emphasis on expression and activity of Mrps. Adult male Wistar rats were divided into the following groups: EE (5 mg/kg daily for 5 days, s.c.), SL (200 micromol/kg daily for 3 days, i.p.), EE+SL (same doses, SL administered the last 3 days of EE treatment), and controls. SL prevented the decrease in bile salt-independent fraction of bile flow induced by EE, in association with normalization of biliary excretion of glutathione. Western blot studies indicate that EE decreased the expression of multidrug resistance-associated protein 2 (Mrp2) by 41% and increased that of Mrp3 by 200%, whereas SL only affected Mrp2 expression (+60%) with respect to controls. The EE+SL group showed increased levels of Mrp2 and Mrp3 to the same extent as that registered for the individual treatments. Real-time polymerase chain reaction studies indicated that up-regulation of Mrp2 and Mrp3 by SL and EE, respectively, was at the transcriptional level. To estimate Mrp2 and Mrp3 activities, apical and basolateral excretion of acetaminophen glucuronide (APAP-glu), a common substrate for both transporters, was measured in the recirculating isolated perfused liver model. Biliary/perfusate excretion ratio was decreased in EE (-88%) and increased in SL (+36%) with respect to controls. Coadministration of rats with SL partially prevented (-53%) impairment induced by EE in this ratio. In conclusion, SL administration to EE-induced cholestatic rats counteracted the decrease in bile flow and biliary excretion of glutathione and APAP-glu, a model Mrp substrate, findings associated with up-regulation of Mrp2 expression.
Instituto de Fisiología Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas Universidad Nacional de Rosario, Suipacha 570 (2000) Rosario, Argentina.
María L
ML
Ruiz
Silvina S M
SS
Villanueva
Marcelo G
MG
Luquita
Shin-ichi
S
Ikushiro
Aldo D
AD
Mottino
Viviana A
VA
Catania
D000074020:ATP Binding Cassette Transporter, Subfamily B, Member 11; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D000082:Acetaminophen / Q000031:analogs & derivatives / Q000378:metabolism; D000818:Animals; D027321:Anion Transport Proteins / Q000378:metabolism; D017920:Antiporters / Q000378:metabolism; D001646:Bile / Q000378:metabolism; D015153:Blotting, Western; D002780:Cholestasis, Intrahepatic / Q000139:chemically induced / Q000378:metabolism / Q000517:prevention & control*; D004997:Ethinyl Estradiol / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D014453:Glucuronosyltransferase / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics / Q000378:metabolism*; D009929:Organ Size / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D064606:SLC4A Proteins; D013148:Spironolactone / Q000494:pharmacology* / Q000627:therapeutic use; D015854:Up-Regulation / Q000187:drug effects
D000074020:ATP Binding Cassette Transporter, Subfamily B, Member 11; D018528:ATP-Binding Cassette Transporters; D000082:Acetaminophen; D027321:Anion Transport Proteins; D017920:Antiporters; D004997:Ethinyl Estradiol; D014453:Glucuronosyltransferase; D005978:Glutathione; D026901:Membrane Transport Proteins; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D012333:RNA, Messenger; D064606:SLC4A Proteins; D013148:Spironolactone; C490548:Abcb11 protein, rat; C114462:multidrug resistance-associated protein 3; C037386:acetaminophen glucuronide; C110655:UDP-glucuronosyltransferase, UGT1A6; C107611:UDP-glucuronosyltransferase, UGT1A7