Chronic renal failure: effect of hemodialysis on gastrointestinal hormones.

Fifteen patients with chronic renal failure (serum creatinine level greater than 5 mg/dl) of long duration (more than 2 years) requiring hemodialysis were studied. Blood samples before and after 4 hours of hemodialysis were assayed for creatinine, blood urea nitrogen, potassium, calcium, glucose, insulin, gastrin, gastric inhibitory polypeptide, vasoactive intestinal polypeptide, pancreatic polypeptide, somatostatin, motilin, and neurotensin levels. Before dialysis, serum gastrin was minimally increased whereas gastric inhibitory polypeptide and pancreatic polypeptide were grossly increased compared with normal fasting values. Hemodialysis produced no changes in serum gastric inhibitory polypeptide, vasoactive intestinal polypeptide, pancreatic polypeptide, somatostatin, motilin, and neurotensin. Slight increases in serum insulin and gastrin levels may have occurred secondary to a dialysis-induced increase in the serum calcium level. The kidneys appear to be a major site of inactivation of insulin, gastrin, gastric inhibitory polypeptide, and pancreatic polypeptide. The gastrin level, although elevated in renal failure patients, may be suppressed by very high circulating levels of gastric inhibitory polypeptide.