INFLUENCE OF PERITONEAL-DIALYSIS SOLUTIONS WITH GLUCOSE AND AMINO-ACIDS ON INGESTIVE BEHAVIOR IN RATS

Continuous ambulatory peritoneal dialysis (CAPD) is often associated w ith malnutrition; reduced intake of nutrients due to anorexia is an im portant factor. The glucose load from glucose-based peritoneal dialysi s (PD) solutions and amino acids from amino acid-based solutions may f avor suppression of the appetite. To study this matter we used a new e xperimental model in free-moving, unstressed male Wistar rats (300 to 350 g) with feeding catheters channeled from the top of the skull to t he oral cavity. When the rats recovered from surgery they were tested under standardized conditions by giving them an intraoral infusion (1 ml/min) of a solution containing 342 g/liter of the sucrose or 97 g/li ter protein solutions while recording the time (volume) of ingestion. Control rats consumed 18.8 +/- 0.9 ml of the sucrose and 39.8 +/- 0.8 ml of the protein solutions. Injections of PD solutions with 13.6, 22. 7 and 38.6 g/liter of glucose reduced the ingestion of sucrose by 12.4 %, 23.6% and o 36.1%, respectively, but did not affect the ingestion o f protein. Injections of 30 ml of PD solutions containing 11, 18 and 3 1 g/liter of amino acids reduced the ingestion of both sucrose by 9.7% , 17.1% and 33.2% and of protein by 13.5%, 25.9% and 33.1%, respective ly. We conclude that in our experimental model, the inhibition of appe tite caused by peritoneal solutions containing glucose or amino acids seems to be specific for each nutritional constituent and not simply a n effect of hyperosmolality or large filling volumes.