Glucagon-stimulated plasma C-peptide and insulin levels in active and non-active acromegalics.
The glucagon-stimulated insulin and C-peptide release in patients with active acromegaly, cured acromegalic patients and healthy controls were studied. There was an elevation of the fasting insulin levels in active acromegalics and the fasting C-peptide levels in both patient groups. After i.v. injection of glucagon the insulin and C-peptide levels increased. The highest levels were recorded in active acromegalics, but cured patients also had higher levels than the control group. The insulin/C-peptide ratio was increased in active acromegalics in comparison with that found for inactive acromegalics and normal controls. In addition, the plasma half-lives (T1/2) of endogenous insulin and C-peptide were measured. It was found that the T1/2 for insulin was increased in active acromegalics only. From this study we conclude that even when the treatment of acromegaly is effective insulin and C-peptide secretion do not normalize due, probably, to increased synthesis and release upon stimulation of the pancreatic beta-cells. In active acromegaly the removal of insulin is probably also reduced.
D000172:Acromegaly / Q000097:blood*; D000328:Adult; D000368:Aged; D002096:C-Peptide / Q000097:blood* / Q000378:metabolism; D005215:Fasting; D005260:Female; D005934:Glucagon / Q000494:pharmacology*; D006207:Half-Life; D006801:Humans; D007328:Insulin / Q000097:blood* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D013268:Stimulation, Chemical
D002096:C-Peptide; D007328:Insulin; D005934:Glucagon