Increased renal expression of aquaporin-3 in rats inhibited type 2 11beta-hydroxysteroid dehydrogenase.
OBJECTIVE
To investigate whether the regulation of aquaporin (AQP) channels is altered by inhibition of type 2 11beta-hydroxysteroid dehydrogenase (11betaHSD2).


METHODS
Male Sprague-Dawley rats were treated with glycyrrhizic acid (GA, 2 g/l drinking water) for 7 days. The expression of AQP2 and AQP3 was determined in the kidney by immunoblotting and immunohistochemistry. The expression of Gsalpha and type VI adenylyl cyclase, and the activity of adenylyl cyclase were also determined.


RESULTS
Following the GA treatment, the expression of 11betaHSD2 was significantly decreased in the kidney. The expression of AQP3 was increased, while that of AQP2 remained unchanged. Plasma renin activity and serum aldosterone levels were decreased. Plasma arginine vasopressin (AVP) levels were comparable between the groups. Neither the forskolin-stimulated cAMP generation nor the expression of Gsalpha and type VI adenylyl cyclase was altered significantly.


CONCLUSIONS
A decreased expression of 11betaHSD2 may result in an upregulation of AQP3, in which AVP/cAMP-dependent mechanisms are unlikely to be involved.
Ma
Seong Kwon
SK
Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea.
Nam
Kwang Il
KI
Kim
Soo Wan
SW
Bae
Eun Hui
EH
Choi
Ki Chul
KC
Lee
JongUn
J
D042842:11-beta-Hydroxysteroid Dehydrogenases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D051399:Aquaporin 2 / Q000378:metabolism; D051400:Aquaporin 3 / Q000378:metabolism* / Q000502:physiology; D001794:Blood Pressure; D019695:Glycyrrhizic Acid / Q000494:pharmacology; D007668:Kidney / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
D000894:Anti-Inflammatory Agents, Non-Steroidal; D051399:Aquaporin 2; D051400:Aquaporin 3; D019695:Glycyrrhizic Acid; D042842:11-beta-Hydroxysteroid Dehydrogenases; D000262:Adenylyl Cyclases; C121100:adenylyl cyclase 6