THE COMPOSITION OF MAMMALIAN PERICARDIAL AND PERITONEAL FLUIDS

Abstract

Blood-free samples of pericardial and peritoneal fluids were collected from various laboratory animals. The vol. of pericardial fluid ranged from 0.4 to 1.9 cc. in rabbits, 0.5 to 2.5 cc. in dogs, and amts. approximating this range in other animals. The vol. of peritoneal fluid in the various animals used ranged from 0 to 50 or 75 cc. The avg. protein content of the pericardial fluid from 34 dogs was 1.70%; from 7 rabbits, 2.16%; 4 monkeys, 1.71%; 2 cats, 2.42%; 1 rat, 2.07%; 2 hens, 3.53%; and from 2 ducks, 2.51%. The avg. protein content of the peritoneal fluid from 11 dogs was 2.61%, and from 5 rabbits, 133%. Albumin/globulin ratios were detd. on the pericardial and peritoneal fluids from some of the dogs and rabbits, but showed little or no similarity to the ratios on the serum of the same animals. The presence of fibrin was shown in both pericardial and peritoneal fluids by the rapid clotting of the fluids immediately after removal from the animal. The chloride content of both fluids was detd. and compared with the chloride content of the serum of the same animals. The chloride ratios thus detd. were found to compare closely with theoretical ratios calculated on the assumption of a Donnan equilibrium. The protein contained in these extra-vascular fluids may easily be derived from the protein of the blood stream by simple diffusion across the blood vascular membrane.