title: Acute effects of exogenous nitric oxide on glucose uptake in skeletal muscle of normoglycaemic and diabetic rats.
abstract: BACKGROUND
  The role of nitric oxide (NO) in the modulation of basal and insulin-stimulated glucose uptake remains controversial. The aim of this study was to investigate the role of NO released from its donors, S-nitrosoglutathione (GSNO) and S-nitroso-N-acetylpenicillamine (SNAP), on glucose uptake in skeletal muscle of normoglyceamic and type 2 diabetic rats.
  
  
  METHODS
  Skeletal muscle strips of type 2 diabetic and normoglycaemic Sprague-Dawley rats were incubated with or without various concentrations (200 microM, 500 microM, 1000 microM, 10 mM & 20 mM) of SNAP or GSNO in the presence or absence of insulin (100 nM or 10 microM). The associated radioactivity was determined by liquid scintillation counting in a Beckman LS6000 scintillation counter programmed for dual-channel counting.
  
  
  RESULTS
  SNAP and GSNO at 1000 microM significantly elevated basal and insulin-stimulated 2-deoxyglucose uptake (P<0.05) in normoglycaemic and diabetic rats. Millimolar concentrations (10 & 20 mM) of GSNO and SNAP significantly decreased basal and insulin-stimulated glucose uptake in skeletal muscle strips of normoglycaemic and type 2 diabetic rats in a concentration-dependent manner (P<0.05). The inhibition of insulin-stimulated glucose uptake was greater in the diabetic rats using both NO donors compared with normoglycaemic rats (P<0.05).
  
  
  CONCLUSIONS
  The stimulatory effect of micromolar concentrations of GSNO and SNAP enhances basal and insulin-stimulated glucose uptake in normoglycaemic and type 2 diabetic rats, however higher concentrations elicited an inhibitory effect in normoglycaemic and diabetic rats. This highlights the NO-glucose uptake mechanism as a possible potential therapeutic target in the treatment of type 2 diabetes.
authors.affiliation: Department of Pathology, University of the West Indies, Kingston 7, Jamaica, West Indies. dmcgrowd@yahoo.com
authors.forename: Donovan
authors.initials: D
authors.lastname: McGrowder
authors.forename: Dalip
authors.initials: D
authors.lastname: Ragoobirsingh
authors.forename: Paul
authors.initials: P
authors.lastname: Brown
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental; D005260:Female; D005947:Glucose / Q000378:metabolism*; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D026423:S-Nitroso-N-Acetylpenicillamine / Q000378:metabolism; D026422:S-Nitrosoglutathione / Q000378:metabolism
chemical_list: D001786:Blood Glucose; D007328:Insulin; D020030:Nitric Oxide Donors; D009569:Nitric Oxide; D026422:S-Nitrosoglutathione; D026423:S-Nitroso-N-Acetylpenicillamine; D005947:Glucose