Indomethacin enhances shuttling of aquaporin-2 despite decreased abundance in rat kidney.
The effect of nonsteroidal antiinflammatory drugs on the regulation of aquaporin-2 (AQP2) water channels in the kidney was determined. Male Sprague-Dawley rats were injected with indomethacin (5 mg/kg twice a day intraperitoneally) for 2 d. The control group was injected with vehicle. The expression of AQP2 proteins was determined in the kidney by immunoblotting and immunohistochemistry. The expression of G(salpha) and type VI adenylyl cyclase was determined by immunoblotting. The activity of adenylyl cyclase complexes was determined by stimulated accumulation of cAMP. Immunoblotting revealed that indomethacin markedly decreased the expression of AQP2. Accordingly, however, the ratio of AQP2 expression in the membrane fraction versus that in the cytoplasmic fraction was increased. The urinary excretion of AQP2 proteins also increased. Immunohistochemistry demonstrated almost exclusive apical labeling of AQP2 with scanty cytoplasmic localization along the collecting duct. The expression of G(salpha) and adenylyl cyclase VI proteins was decreased. The generation of cAMP provoked by arginine vasopressin, sodium fluoride, or forskolin was blunted. These results suggest that indomethacin increases the shuttling of AQP2 while it decreases its abundance in the collecting duct.
Kim
Soo Wan
SW
Department of Physiology, Chonnam National University Medical School, 5 Hak-dong, Gwangju 501-746, Korea.
Kim
Joon Wan
JW
Choi
Ki Chul
KC
Ma
Seong Kwon
SK
Oh
Yoonwha
Y
Jung
Ju-Young
JY
Kim
Jin
J
Lee
JongUn
J
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D051399:Aquaporin 2; D020346:Aquaporins / Q000378:metabolism*; D001127:Arginine Vasopressin / Q000097:blood; D015153:Blotting, Western; D000242:Cyclic AMP / Q000378:metabolism; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000378:metabolism; D007150:Immunohistochemistry; D007213:Indomethacin / Q000494:pharmacology*; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D014867:Water / Q000378:metabolism
D000894:Anti-Inflammatory Agents, Non-Steroidal; C496025:Aqp2 protein, rat; D051399:Aquaporin 2; D020346:Aquaporins; D014867:Water; D001127:Arginine Vasopressin; D000242:Cyclic AMP; D019205:GTP-Binding Protein alpha Subunits, Gs; D000262:Adenylyl Cyclases; C121100:adenylyl cyclase 6; D007213:Indomethacin