title: Is L-glutathione more effective than L-glutamine in preventing enteric diabetic neuropathy?
abstract: BACKGROUND
  Diabetes and its complications appear to be multifactorial. Substances with antioxidant potential have been used to protect enteric neurons in experimental diabetes.
  
  
  OBJECTIVE
  This study evaluated the effects of supplementation with L-glutamine and L-glutathione on enteric neurons in the jejunum in diabetic rats.
  
  
  METHODS
  Rats at 90 days of age were distributed into six groups: normoglycemic, normoglycemic supplemented with 2 % L-glutamine, normoglycemic supplemented with 1 % L-glutathione, diabetic (D), diabetic supplemented with 2 % L-glutamine (DG), and diabetic supplemented with 1 % L-glutathione (DGT). After 120 days, the jejunums were immunohistochemically stained for HuC/D+ neuronal nitric oxide synthase (nNOS) and vasoactive intestinal polypeptide (VIP). Western blot was performed to evaluate nNOS and VIP. Submucosal and myenteric neurons were quantitatively and morphometrically analyzed.
  
  
  RESULTS
  Diabetic neuropathy was observed in myenteric HuC/D, nNOS, and VIP neurons (p < 0.05). In the submucosal plexus, diabetes did not change nitrergic innervation but increased VIPergic neuronal density and body size (p < 0.05). Supplementation with L-glutathione prevented changes in HuC/D neurons in the enteric plexus (p < 0.05), showing that supplementation with L-glutathione was more effective than with L-glutamine. Myenteric nNOS neurons in the DGT group exhibited a reduced density (34.5 %) and reduced area (p < 0.05). Submucosal neurons did not exhibit changes. The increase in VIP-expressing neurons was prevented in the submucosal plexus in the DG and DGT groups (p < 0.05).
  
  
  CONCLUSIONS
  Supplementation with L-glutathione exerted a better neuroprotective effect than L-glutamine and may prevent the development of enteric diabetic neuropathy.
authors.affiliation: Department of Pharmacy, Universidade Estadual de Maringá, Maringá, PR, Brazil.
authors.forename: Catchia
authors.initials: C
authors.lastname: Hermes-Uliana
authors.forename: Cynthia Priscilla do Nascimento Bonato
authors.initials: CP
authors.lastname: Panizzon
authors.forename: Aline Rosa
authors.initials: AR
authors.lastname: Trevizan
authors.forename: Camila Caviquioli
authors.initials: CC
authors.lastname: Sehaber
authors.forename: Francielle Veiga
authors.initials: FV
authors.lastname: Ramalho
authors.forename: Heber Amilcar
authors.initials: HA
authors.lastname: Martins
authors.forename: Jacqueline Nelisis
authors.initials: JN
authors.lastname: Zanoni
mesh_terms: D000818:Animals; D015153:Blotting, Western; D003921:Diabetes Mellitus, Experimental / Q000150:complications / Q000188:drug therapy*; D003929:Diabetic Neuropathies / Q000188:drug therapy / Q000517:prevention & control*; D019587:Dietary Supplements; D017615:Enteric Nervous System / Q000166:cytology / Q000187:drug effects; D005973:Glutamine / Q000627:therapeutic use*; D005978:Glutathione / Q000627:therapeutic use*; D007410:Intestinal Diseases / Q000188:drug therapy* / Q000209:etiology; D007579:Jejunal Diseases / Q000188:drug therapy* / Q000209:etiology; D008297:Male; D052248:Nitric Oxide Synthase Type I / Q000235:genetics / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar
chemical_list: D005973:Glutamine; D052248:Nitric Oxide Synthase Type I; D005978:Glutathione