Immunoneutralization of Endogenous Glucagon With Monoclonal Glucagon Antibody Normalizes Hyperglycaemia in Moderately Streptozotocin-Diabetic Rats

Diabetologia. 1994 Oct;37(10):985-93. doi: 10.1007/BF00400461.

Abstract

The role of glucagon in diabetic hyperglycaemia has been a matter of controversy because of difficulties in the production of selective glucagon deficiency. We developed a high-capacity (40 nmol/ml), high-affinity (0.6 x 10(11) l/mol) monoclonal glucagon antibody (Glu-mAb) and gave i.v. injections (4 ml/kg) to rats in order to study the effect of selective glucagon deficiency on blood glucose. Controls received a mAb against trinitrophenyl. Glu-mAb completely abolished the hyperglycaemic effect of 2.86 nmol/kg glucagon in normal rats (p < 0.05, n = 6). In moderately hyperglycaemic rats injected with streptozotocin as neonates (N-STZ), Glu-mAb abolished a postprandial increase in blood glucose (from 11.2 +/- 0.7 mmol/l to 17.3 +/- 1.8 mmol/l in controls vs 10.5 +/- 0.9 mmol/l to 9.3 +/- 1.0 mmol/l; cross-over: n = 6, p < 0.05). No significant effect of Glu-mAb treatment was observed in more hyperglycaemic N-STZ rats (cross-over, n = 4) and in severely hyperglycaemic rats injected with STZ as adults (n = 6), but after insulin treatment of the latter, at doses partially restoring blood glucose levels (12.7 +/- 4.3 mmol/l), Glu-mAb administration almost normalized blood glucose (maximal difference: 6.0 +/- 3.8 mmol/l; cross-over: n = 5, p < 0.05). In conclusion, our results provide strong additional evidence for the hypothesis that glucagon is involved in the pathogenesis of diabetes. The hormone plays an important role in the development of STZ-diabetic hyperglycaemia, but glucagon neutralization only leads to normoglycaemia in the presence of insulin.

MeSH terms

  • Animals
  • Antibodies, Monoclonal / immunology*
  • Antibodies, Monoclonal / therapeutic use
  • Blood Glucose / analysis
  • Blood Glucose / physiology
  • Diabetes Mellitus, Experimental / metabolism*
  • Diabetes Mellitus, Experimental / therapy
  • Diabetes Mellitus, Type 2 / metabolism*
  • Diabetes Mellitus, Type 2 / therapy
  • Glucagon / deficiency
  • Glucagon / immunology*
  • Glucagon / metabolism
  • Hyperglycemia / blood
  • Hyperglycemia / metabolism*
  • Insulin / therapeutic use
  • Male
  • Rats
  • Rats, Sprague-Dawley
  • Streptozocin

Substances

  • Antibodies, Monoclonal
  • Blood Glucose
  • Insulin
  • Streptozocin
  • Glucagon