Kinetics of distribution of D2O in canine intestinal tissues

Abstract

The uptake of DHO [deuterated water] by the mucosa, submucosa, muscle, and mesentery of isolated canine intestinal segments during artificial perfusion with arterial blood having a constant DHO concentration has been studied. When the data are subjected to compartmental analysis, all 4 tissues appear to contain 3 water compartments with the turnover constant of the slowest being in each instance only 1-2%/min. A plausible anatomical arrangement which seems most consistent with ancillary information is that 1 of the 3 compartments is identical with the extracellular space, with the other 2 being intracellular. The slower of the latter 2 may be identified with the nucleus and mitochondria.