Membrane transport in relation to net uptake of glucose in the perfused rat hindlimb. Stimulatory effect of insulin, hypoxia and contractile activity.
The paired-tracer dilution method applied to the perfused rat hindlimb model was used to study glucose transport in relation to net glucose uptake in skeletal muscle tissue. 2-deoxyglucose was used as an analogue for glucose, since this eliminates the problem with release of labelled metabolites. The affinity of 2-deoxyglucose for the glucose carrier was shown to be indistinguishable from that of glucose. An insulin dose-response study showed maximal stimulation of glucose uptake and transport at 0.1 unit/l, and 75% of maximal stimulation at 0.01 unit of insulin/l. Hypoxia and contractile activity stimulated the 2-deoxyglucose transport rate similarly, and the stimuli were not additive, suggesting a common mechanism. The presence of insulin did not increase the effect of hypoxia or contractile activity, indicating no permissive effect of insulin. The 2-deoxyglucose transport rate was closely correlated with and always higher than that of glucose uptake, demonstrating that the transport is never rate-limiting for the net glucose uptake and that both processes are regulated together. Significant correlations between the 2-deoxyglucose transport rate and the intramuscular concentration of phosphocreatine suggest regulation of the glucose utilization by the energy state of the skeletal muscle tissue.
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003847:Deoxyglucose / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D005947:Glucose / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009132:Muscles / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains
D007328:Insulin; D003847:Deoxyglucose; D005947:Glucose; D010100:Oxygen