Abstract
Gastrointestinal bleeding is a well-known complication of chronic renal failure. Studies on the metabolism of gastrin suggested that the kidney is a major site of gastrin degradation. To elucidate whether immunoreactive gastrin (IRG) plays any important role in so called “uremic gastropathy, ” IRG concentration was measured by using two kinds of antisera, 2604 by Rehfeld and R2702 by Yanaihara. The former detects four main forms of total IRG (TG) with equimolar potency, and the latter exclusively detects G34 and its N-terminal fragments. In 33 patients with chronic renal failure (24 with, 9 without hemodialysis) and 12 normal subjects, blood samples were taken in the fasting state, before and after dialysis and after test meals.
Basal TG concentration was significantly higher in patients with chronic renal failure, irrespective of whether or not they were on dialysis. TG levels were not correlated with serum creatinine levels. TG levels were decreased by 37%, as a result of hemodialysis, but G34 levels showed no significant change. A small amount of IRG was detected in the dialysate by antiserum 2604. As to the postprandial IRG release, in patients with renal failure, both TG and G34 levels attained their peak values 60 minutes after the test meal, and these high values were more prolonged than those in normal subjects.
The finding that the predominant circulating form of gastrin in chronic renal failure in G34, and the fact that G17 is 6 times more potent than G34 in stimulating gastric acid secretion would suggest that hypergastrinemia has minimal significance in acid secretion.
