Serum gastrin in patients with chronic renal failure.

The realisation that circulating gastrin is heterogeneous necessitates a reappraisal of gastrin's role in the increased incidence of duodenal ulcer disease that occurs in chronic renal failure. Radioimmunoassays employing region-specific antisera have been used to examine renal and extrarenal factors controlling serum gastrin concentration in patients with chronic renal failure. The present study has shown that basal serum gastrin concentrations measured with a carboxyl-terminal specific antibody were significantly higher in eight patients with chronic renal failure treated by dietary restriction (388+/-196 pM) than in 14 patients with chronic renal failure treated by haemodialysis (28.7+/-4.6 pM). However, basal gastrin concentrations in both groups of patients were significantly higher than in 25 normal subjects (12.3+/-1.8 pM) and showed significant negative correlations with maximal gastric acid secretion (p < 0.01). Markedly raised basal gastrin concentrations were observed only in chronic renal failure patients who were also achlorhydric. Although the peak postprandial increment in big gastrin concentration in 11 chronic renal failure patients (34.0+/-7.5 pM) was significantly greater (p < 0.05) than in 25 normal subjects (19.5+/-4.6 pM), the little gastrin responses were not significantly different. In addition, clearance of exogenous little gastrin was similar in four chronic failure patients (clearance half time: 8.1+/-0.7 min) and four normal subjects (clearance half time: 6.5+/-1.2 min). These studies suggest that the human kidney is unimportant in the metabolism of little gastrin. As circulating little gastrin is six times more potent than big gastrin in stimulating acid secretion, these studies suggest that the raised gastrin concentrations observed in patients with chronic renal failure have little significance in terms of their increased incidence of duodenal ulcer disease.