Comparison of Metabolic Effects of Glucagon and Calcitonin and Assessment of Direct Effect of Glucagon on Calcitonin Level in Athyroid Man

Summary

The effect of intramuscular administration of glucagon (Glg) and Calcitonin (Ct) on the pattern of serum calcium (Ca), inorganic phosphorus (P), blood glucose (BS), immunoreactive insulin (IRI) and growth hormone (GH) was investigated in 14 patients after total thyroid ablation during replacement therapy. In seven patients the pattern of Ct after Glg administration was assessed in the same conditions.

Both hormones induced a prompt and marked decrease of Ca without any differences between effect of Glg and Ct. The decline of P due to Glg is more rapid and marked than that due to Ct, the difference being significant from 60 to 120 min.

Glg caused a rapid and marked rise of BS and IRI with a tendency toward normalization up to 180 min, GH rose significantly from 120 to 180 min. The changes of BS and IRI due to Ct were slow and less marked, but prolonged: level of BS increased and that of IRI decreased. No effect of Ct administration on GH was recorded.

In general, neither the effects of Glg nor those of Ct were influenced by hypothyroidism. This fact may be of importance for use of Glg in testing GH reserve in hypothyroidism.

Ct after Glg administration in athyroid patients failed to exhibit any significant changes. Thus our results support the assumption about similar and independent action of Glg and Ct on calcium and phosphate homeostase and different effects of both hormones on glucose metabolism.

Key-Words:

Glucagon - Calcitonin - Serum Calcium - Serum Phosphorus - Blood Glucose - Immunoreactive Insulin - Growth Hormone - Thyroid Ablation