Enhanced insulin-dependent glucose utilization in iron-deficient veal calves.
Based on studies in Fe-deficient calves demonstrating enhanced blood lactate concentrations during treadmill exercise, the hypothesis was advanced that glucose metabolism is also disturbed at rest. Insulin-dependent glucose metabolism was therefore investigated in calves fed milk replacer containing 20 or 50 mg Fe/kg. Calves receiving only 20 mg Fe/kg of milk replacer developed moderate Fe deficiency anemia and had lower average daily gain than calves fed milk replacer containing 50 mg Fe/kg, but feed intake and feed refusals did not differ between groups. In Fe-deficient calves, insulin responses to glucose, based on intravenous and oral glucose tolerance and hyperglycemic clamp tests, were normal. Using hyperglycemic and euglycemic hyperinsulinemic clamps combined with [13C6]glucose infusions, glucose utilization and tissue sensitivity to insulin were greater in Fe-deficient calves than in Fe-adequate calves. Observed reductions in growth performance may be explained by decreased activity of Fe-dependent enzymes, increased anaerobic glycolysis and lactate-glucose cycling, adaptations that are expected to be energy expensive.
Hostettler-Allen
R
R
Division of Nutrition Pathology, University of Berne, Switzerland.
Tappy
L
L
Blum
J W
JW
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D002417:Cattle; D002418:Cattle Diseases / Q000378:metabolism*; D005502:Food; D015309:Glucose Clamp Technique; D005951:Glucose Tolerance Test; D006454:Hemoglobins / Q000378:metabolism; D007328:Insulin / Q000097:blood / Q000494:pharmacology*; D007501:Iron / Q000008:administration & dosage / Q000097:blood; D000090463:Iron Deficiencies; D007700:Kinetics; D008297:Male; D015430:Weight Gain
D001786:Blood Glucose; D006454:Hemoglobins; D007328:Insulin; D007501:Iron