THE USE OF THE CAT IN THE BIOASSAY OF CHOLERETIC AGENTS

¹ Division of Biological Research, G. D. Searle and Company, Chicago 80, Ill.
² Agricultural Experiment Station, Oregon State College, Corvallis, Oregon

The influence of various factors on bile flow and bile solids excretion have been studied in 211 acute biliary fistula cats. These factors include sex, body weight, liver weight, blood pressure and bile depletion. The basal rate of bile flow in both male and female cats is significantly correlated with both body weight and liver weight; the latter two parameters are also highly correlated. Similar relationships were found for total solids excretion. No relationship was found between bile flow and mean arterial blood pressure.

A simple 5-hour assay for choleretic agents using dehydrocholic acid as the standard is described. The assay is based on the increase in bile volume (ml./cat) during a 4-hour collection period above the expected control for the same period. Adjustment for a significant regression of the 4-hour volume on the first hour volume eliminates the effect of variations in body weight or liver weight. Sex difference has no apparent influence on the results. Similar measurements on total solids excretion are complicated by the possible biliary excretion of the test agent itself and a possible remedy is discussed.