Demonstration of Deoxyribonuclease I in Bile Juice by a Non-Radioactive Zymographical Method
Deoxyribonuclease I (DNase I) is a digestive enzyme which distributes in digestive fluids such as pancreatic juice and saliva. The distribution of DNase I in bile juice is still unknown. This is the first report to prove the existence of DNase I and its origin in bile juice, using human and rat bile juice obtained during decompression and ligation of the common bile duct (CBD). DNase I was detected by a non-radioactive zymographical method modified activity blotting method with renaturation and blotting buffer systems. The identification as human and rat DNase I was based on their characteristics. We showed that human and rat bile juice DNase I were specific enzymes hydrolyzing double-stranded DNA down to 5'phosphooligonucleotides at each optimal condition, and that G-actin completely inhibited enzyme activities. These characteristics were compatible with the DNase I previously reported in humans and rats. In addition, the human bile juice DNase I increased following the recovery of biliary stasis by percutaneous transhepatic cholangio drainage (PTCD). These results prove that DNase I exists in bile juice with obstructive jaundice, and suggest the possibility that it originates from liver tissue.