CONSTANT ACCESS TO CIRCULATION AND INTESTINAL-TRACT OF UNRESTRAINED RAT

A new less stressful and less expensive apparatus for continuously infusing the unrestrained rat is described. The system was used for gastrostomy feeding and for infusing both the systemic and portal circulations. Within 2 days of leashing, rats are acclimated to the apparatus and when fed ad lib, they maintain a rate of weight gain (4.6 g/day) comparable to ad lib fed unleashed rats (4.7 g/day). A liquid diet which results in near normal weight gain (4.4 g/day) is presented. The incidence of renal infarction secondary to cannulation of the aortic arch with PE 50 tubing can be reduced by making the cannula tip of pliable Silastic tubing.