Movement of intrapancreatic calcium in dogs with experimental pancreatic lithiasis. With special reference to the process of pancreatic calculus formation.

This study was performed to clarify the movement of calcium in the pancreas of dogs with chronic pancreatitis, using scanning and transmission electron microscopes (SEM, TEM) equipped with X-ray elemental microanalyzers. Eleven adult mongrel dogs underwent incomplete ligation of the pancreatic duct. After the procedure, the levels of pancreatic enzymes in the serum did not change for 9 mo, but the endocrine function was reduced gradually. Of all dogs, 5 revealed pancreatic sclerosis, and 2 at 9 mo had calculi, 2-4 mm in size, in the small pancreatic duct. SEM examination revealed the intralobular fibrosis and irregularity of the pancreatic duct wall, and TEM examination revealed the intralobular fibrosis and irregularity of the pancreatic duct wall, and TEM examination demonstrated the amorphous or crystalloid substances and secreted granules in the acinar lumen or ductule. In elemental analysis spectra using SEM, a high calcium peak was seen in the pancreatic duct wall. In elemental analysis spectra using TEM, a high calcium peak was observed in the amorphous or crystalloid substances, and a high ratio of Ca/K was seen in these substances. Calcium was also detected in the secreted granules or microvilli. These results suggest that there is a process of calculus formation based on the congregation of the intraductular substances containing a large quantity of calcium.