title: Insulin resistance of hind-limb tissues in vivo in lactating sheep.
abstract: 1. The effects of varying the plasma insulin concentration by infusion while maintaining euglycaemia by infusion of glucose on nutrient arterio-venous differences across the hind-limb and mammary gland in lactating and non-lactating sheep were investigated. 2. Insulin infusion increased the glucose arterio-venous difference across the hind-limb; this effect of insulin was decreased by lactation, suggesting that lactation induces insulin resistance in skeletal muscle. 3. Lactation increased but insulin infusion decreased the plasma concentrations of acetate, beta-hydroxybutyrate and non-esterified fatty acids. 4. Insulin infusion decreased the arterio-venous differences of acetate and hydroxybutyrate across the hind-limb; this effect of insulin is probably indirect, resulting from the decrease in plasma concentrations of these metabolites. 5. Infusion of insulin had no effect on the glucose arterio-venous difference across the mammary gland, but did decrease the oxygen arterio-venous difference. 6. The results suggest that lactation results in insulin resistance in skeletal muscle, at least with respect to glucose utilization; this should facilitate the preferential utilization of glucose by the mammary gland.
authors.affiliation: Hannah Research Institute, Ayr, Scotland, U.K.
authors.forename: R G
authors.initials: RG
authors.lastname: Vernon
authors.forename: A
authors.initials: A
authors.lastname: Faulkner
authors.forename: W W
authors.initials: WW
authors.lastname: Hay
authors.forename: D T
authors.initials: DT
authors.lastname: Calvert
authors.forename: D J
authors.initials: DJ
authors.lastname: Flint
mesh_terms: D000085:Acetates / Q000378:metabolism; D000818:Animals; D005947:Glucose / Q000378:metabolism*; D006614:Hindlimb; D006885:Hydroxybutyrates / Q000378:metabolism; D007328:Insulin / Q000502:physiology*; D007333:Insulin Resistance; D007773:Lactates / Q000378:metabolism; D007774:Lactation; D008321:Mammary Glands, Animal / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D012756:Sheep
chemical_list: D000085:Acetates; D006885:Hydroxybutyrates; D007328:Insulin; D007773:Lactates; D005947:Glucose; D010100:Oxygen