Glucagon suppression improves glucoregulation in moderate but not chronic severe diabetes
Lickley, H.L.; Kemmer, F.W.; Doi, K.; Vranic, M.
American Journal of Physiology 245(4): E424-E429
1983
ISSN/ISBN: 0002-9513 PMID: 6137957 Document Number: 201740
Glucose kinetics were studied during a 6-h somatostatin infusion in 6 alloxan-diabetic dogs (moderately severe diabetes) and 5 depancreatized dogs deprived of insulin treatment for 3 days (prolonged severe diabetes). Plasma immunoreactive glucagon (IRG) decreased 70% in alloxan-diabetic and 80% in depancreatized dogs. Portal vein plasma immunoreactive insulin (IRI) fell (17.0 to 5.5 mu U/ml) as did peripheral vein IRI (6.7 to 4.7 mu U/ml) in the alloxan-diabetic dogs. In the depancreatized dogs plasma IRI was undetectable. Plasma glucose concentrations fell (278 to 169 mg/100 ml) during IRG suppression in the alloxan-diabetic dogs due to a rapid and sustained decrease in glucose production (Ra) (6.0 to 3.6 mg/kg min). Glucose disappearance (Rd) decreased gradually (5.9 to 3.9 mg/kg min). In the depancreatized dogs, IRG suppression did not change glucose concentrations or kinetics. Thus, glucagon suppression decreased glycaemia by decreasing Ra only in moderately severe diabetes. This was associated with decreased rather than improved glucose utilization. The ineffectiveness of glucagon suppression during prolonged severe diabetes could relate to the degree and duration of the metabolic derangement and indicate that the continuous presence of some insulin is necessary for glucagon suppression to improve glucose homeostasis.