Effect of Hypaque on Mouse Peritoneum

Abstract

Increasing popularity of water-soluble agents for examination of the gastrointestinal tract prompted an investigation of peritoneal reaction to Hypaque. There is a considerable, and, at times, controversialliterature on barium contamination of the abdominal cavity (1-5). It was not our intention to confirm or deny any antecedent study but rather to compare the effects of instilling sterile saline, 25 per cent Hypaque, and barium into the peritoneal cavity of mice. Material and Methods Initial experiments indicated that 2.0 c.c. of fluid was the maximum volume that could be safely instilled into the peritoneal cavity of the mouse. Intraperitoneal injections were made of 0.5, 1.0, and 2.0 c.c. of sterile saline, Baroloid,2 and 25 per cent Hypaque. Just prior to the experiment, the proprietary preparations were freshly mixed: to 180 c.c, of tap water 3.5 ounces of Baroloid were added; to 100 c.c. of tap water, 25 grams of powdered Hypaque, making a 25 per cent solution. There were 30 mice in each group, permitting sacrifice in pairs at the end of one, six, twenty-four, seventy-two hours, and one week. Cultures were made of all utensils and of the media prior to injection, and of the peritoneal cavities at the time of sacrifice. On sacrifice, sections were taken of the liver, spleen, kidneys, and the peritoneal surface. The latter is such a tenuous structure in mice that a section of diaphragm with its peritoneal covering was found best for study. Viscera were obtained for study of reaction on visceral peritoneum. Results A. Culture: Every attempt was made to insure, so far as possible, that any peritonitis following injection was the result of the agent itself and not of organisms introduced. Prior to injection cultures were made of Baroloid and of Hypaque to see whether or not these agents harbored organisms or had any bacteriostatic action. Baroloid routinely harbored B. subtilis and supported growth of E. coli. Hypaque was consistently sterile and supported growth of E. coli for six hours. Cultures taken at twenty-four hours and later were sterile. A latent bactericidal action may therefore be claimed for Hypaque. In addition, cultures were made from the tap water used and of the various mixing appliances employed. Tap water was sterile but the utensils harbored various Staphylococci, none of which were gastrointestinal pathogens. With a few exceptions that may have been due to contamination, organisms recovered from peritoneal cavities were identical with those present in the agent prior to injection. A few animals died prior to the time set for sacrifice. Their peritoneal cavities were grossly contaminated, suggesting bowel puncture during injection.