Effects of alpha-lipoic acid on ischemia-reperfusion-induced renal dysfunction in rats

Am J Physiol Renal Physiol. 2008 Jan;294(1):F272-80. doi: 10.1152/ajprenal.00352.2007. Epub 2007 Nov 21.

Abstract

We investigated whether alpha-lipoic acid (alpha-LA), an antioxidant, attenuates the ischemia-reperfusion (I/R)-induced dysregulation of these transporters. Both renal pedicles of male Sprague-Dawley rats were clamped for 40 min. alpha-LA (80 mg/kg) was administered intraperitoneally before and immediately after induction of ischemia. After 2 days, the expression of aquaporins (AQPs), sodium transporters, and nitric oxide synthases (NOS) was determined in the kidney by immunoblotting and immunohistochemistry. The expression of endothelin-1 (ET-1) mRNA was determined by real-time PCR. Activities of adenylyl cyclase and guanylyl cyclase were measured by stimulated generation of cAMP and cGMP, respectively. The expression of AQP1-3 as well as that of the alpha(1)-subunit of Na-K-ATPase, type 3 Na/H exchanger, Na-K-2Cl cotransporter, and Na-Cl cotransporter was markedly decreased in response to I/R. The expression of type VI adenylyl cyclase was decreased in I/R-injured rats, which was counteracted by the treatment of alpha-LA. AVP-stimulated cAMP generation was blunted in I/R rats and was then ameliorated by alpha-LA treatment. alpha-LA treatment attenuated the downregulation of AQPs and sodium transporters. The expression of endothelial NOS was decreased in I/R rats, which was prevented by alpha-LA. The cGMP generation in response to sodium nitroprusside was blunted in I/R rats, which was also significantly prevented by alpha-LA. The mRNA expression of ET-1 was increased, which was recovered to the control level by alpha-LA treatment. In conclusion, alpha-LA treatment prevents I/R-induced dysregulation of AQPs and sodium transporters in the kidney, possibly through preserving normal activities of local AVP/cAMP, nitric oxide/cGMP, and ET systems.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenylyl Cyclases / metabolism
  • Animals
  • Antioxidants / pharmacology*
  • Aquaporins / metabolism
  • Cyclic GMP / metabolism
  • Endothelin-1 / metabolism
  • Guanylate Cyclase / metabolism
  • Kidney / drug effects
  • Kidney / metabolism
  • Kidney / physiopathology*
  • Male
  • Models, Animal
  • Nitric Oxide / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Cytoplasmic and Nuclear / metabolism
  • Reperfusion Injury / metabolism
  • Reperfusion Injury / prevention & control*
  • Sodium-Hydrogen Exchanger 3
  • Sodium-Hydrogen Exchangers / metabolism
  • Sodium-Potassium-Chloride Symporters / metabolism
  • Sodium-Potassium-Exchanging ATPase / metabolism
  • Soluble Guanylyl Cyclase
  • Solute Carrier Family 12, Member 1
  • Thioctic Acid / pharmacology*

Substances

  • Antioxidants
  • Aquaporins
  • Endothelin-1
  • Receptors, Cytoplasmic and Nuclear
  • Slc12a1 protein, rat
  • Sodium-Hydrogen Exchanger 3
  • Sodium-Hydrogen Exchangers
  • Sodium-Potassium-Chloride Symporters
  • Solute Carrier Family 12, Member 1
  • Nitric Oxide
  • Thioctic Acid
  • Adenylyl Cyclases
  • Guanylate Cyclase
  • Soluble Guanylyl Cyclase
  • Sodium-Potassium-Exchanging ATPase
  • Cyclic GMP