Gastric emptying of liquids in rats with acute renal insufficiency

The gastric emptying of watery meals was studied in 112 male Wistar rats. The meals utilized were saline and glucose-saline solutions whose emptying was assessed 10 and 30 minutes after administration. A liquid 5% glucose meal and a 0.25 M sodium bicarbonate meal were assessed after 30 minutes and a commercial meal was assessed after 60 minutes. For each study time eight control animals and eight animals bilaterally nephrectomized 48 hours before the gastric emptying tests were used. The meals were labeled with red phenol and the gastric residue was determined by standard methodology. A blood sample to determine serum creatine and blood gases analysis was obtained from 22 animals of the control group and the same number of nephrectomized animals. At the time of the gastric emptying tests, the nephrectomized animals had significantly higher levels of creatinine and moderate metabolic acidosis. Results for the saline meal showed that at 10 minutes there was a significant delay in emptying in animals with renal insufficiency. Results for the glucose-saline meal were similar to the saline alone group, except that they did not differ significantly between the control group and the nephrectomized groups. There was a significant delay in the emptying of all the other meals in the animals with renal insufficiency. These data suggest that uremia does not lead to serious disturbances in gastric motility, but that it does interfere with the mechanisms controlling gastric emptying.