Effect of temperature on stability of eight components of porcine gallbladder bile

Our aim was to evaluate the stability of eight components of porcine bile (pH, total and ionized calcium, total and unconjugated bilirubin, phospholipid, cholesterol, and bile salts) over a 17-day period at three temperatures: -15, 4, and 37 degrees C. The pH and concentrations of total and ionized calcium, phospholipid, cholesterol, and bile salts were stable over 17 days. Total bilirubin was stable at -15 degrees C, but declined over 17 days by approximately 25% at 4 degrees C and 70% at 37 degrees C (P < 0.003). A rapid increase in the unconjugated bilirubin was seen within two days at all temperatures to between 7.5 and 12 times the levels at day 0 (P < 0.009). Thereafter unconjugated bilirubin at -15 and 4 degrees C continued to increase at a much slower rate. By contrast, unconjugated bilirubin at 37 degrees C declined beginning on day 4 and fell to 1.33 times levels at day 0 by day 17 (P < 0.002). We conclude that bile can be stored at -15 degrees C for 17 days with stability of most components, but unconjugated bilirubin will rise. The loss in total bilirubin is significant at 37 degrees C.