title: α-Lipoic acid normalizes nociceptive neuronal activity at the spinal cord of diabetic rats.
abstract: OBJECTIVE
  To evaluate the effects of antioxidant treatment of streptozotocin (STZ)-diabetic rats with α-lipoic acid (α-LA) in neuronal and microglial activation at the spinal cord, an important relay station of nociceptive transmission. Because of the role of the potassium chloride co-transporter 2 (KCC2) in neuronal activation at the spinal cord and the influence of microglia in KCC2 expression, we also evaluated the effects of α-LA in KCC2 expression at the spinal cord.
  
  
  METHODS
  Four weeks after STZ injection, the rats received daily intraperitoneal injections of α-LA (100 mg/kg), during 2 weeks. Mechanical nociception was evaluated before and after α-LA treatment. Spinal cords were immunoreacted against 8-OH-dG (marker of oxidative stress damage), Fos (marker of neuronal activation) and CD11b (marker of microglia). KCC2 expression was evaluated by immunohistochemistry and western blotting.
  
  
  RESULTS
  Treatment with α-LA decreased the 8-OH-dG and Fos expressions to controls' levels, but did not affect CD11b. Treatment with α-LA alleviated mechanical hyperalgesia and partially corrected KCC2 expression.
  
  
  CONCLUSIONS
  This study shows that neuronal hyperactivity at the spinal cord of STZ-diabetic rats can be corrected by α-LA, which may account for alleviation of mechanical hyperalgesia. These effects are probably partially mediated by KCC2, but are independent from microglia.
authors: Institute of Histology and Embryology of Faculty of Medicine of Porto and IBMC, University of Porto, Porto, Portugal.
authors: C
authors: C
authors: Morgado
authors: P
authors: P
authors: Pereira-Terra
authors: I
authors: I
authors: Tavares
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology*; D003921:Diabetes Mellitus, Experimental / Q000150:complications / Q000188:drug therapy*; D008297:Male; D009619:Nociceptors / Q000187:drug effects* / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000187:drug effects* / Q000378:metabolism; D013311:Streptozocin; D008063:Thioctic Acid / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D013311:Streptozocin; D008063:Thioctic Acid