Nitric oxide increases glucose uptake through a mechanism that is distinct from the insulin and contraction pathways in rat skeletal muscle

Diabetes. 2001 Feb;50(2):241-7. doi: 10.2337/diabetes.50.2.241.

Abstract

Insulin, contraction, and the nitric oxide (NO) donor, sodium nitroprusside (SNP), all increase glucose transport in skeletal muscle. Some reports suggest that NO is a critical mediator of insulin- and/or contraction-stimulated transport. To determine if the mechanism leading to NO-stimulated glucose uptake is similar to the insulin- or contraction-dependent signaling pathways, isolated soleus and extensor digitorum longus (EDL) muscles from rats were treated with various combinations of SNP (maximum 10 mmol/l), insulin (maximum 50 mU/ml), electrical stimulation to produce contractions (maximum 10 min), wortmannin (100 nmol/l), and/or the NO synthase (NOS) inhibitor NG-monomethyl-L-arginine (L-NMMA) (0.1 mmol/l). The combinations of SNP plus insulin and SNP plus contraction both had fully additive effects on 2-deoxyglucose uptake. Wortmannin completely inhibited insulin-stimulated glucose transport and only slightly inhibited SNP-stimulated 2-deoxyglucose uptake, whereas L-NMMA did not inhibit contraction-stimulated 2-deoxyglucose uptake. SNP significantly increased the activity of the alpha1 catalytic subunit of 5'AMP-activated protein kinase (AMPK), a signaling molecule that has been implicated in mediating glucose transport in fuel-depleted cells. Addition of the NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME) (1 mg/ml) to the drinking water of rats for 2 days failed to affect the increase in muscle 2-deoxyglucose uptake in response to treadmill exercise. These data suggest that NO stimulates glucose uptake through a mechanism that is distinct from both the insulin and contraction signaling pathways.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Deoxyglucose / pharmacokinetics
  • Enzyme Inhibitors / pharmacology
  • Glucose / metabolism*
  • In Vitro Techniques
  • Insulin / physiology*
  • Male
  • Motor Activity / physiology
  • Muscle Contraction / physiology*
  • Muscle, Skeletal / drug effects
  • Muscle, Skeletal / physiology*
  • NG-Nitroarginine Methyl Ester / pharmacology
  • Nitric Oxide / physiology*
  • Nitroprusside / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • omega-N-Methylarginine / pharmacology

Substances

  • Enzyme Inhibitors
  • Insulin
  • Nitroprusside
  • omega-N-Methylarginine
  • Nitric Oxide
  • Deoxyglucose
  • Glucose
  • NG-Nitroarginine Methyl Ester