Pharmacokinetics of three contrast media in experimental pancreatography

Diatrizoate, iohexol and ioxaglate were compared in experimental pancreatography in piglets. Outflow of contrast medium (CM) through the pancreatic papilla was permitted (n = 14) or impaired (n = 17) during examination. The CM concentrations were measured in portal and systemic plasma and in lymph to study the absorption of CM. Absorption of diatrizoate and iohexol was similar in both types of experiment, but radiographically, diatrizoate escaped significantly earlier from the pancreatic duct when outflow was permitted (p less than 0.01), suggesting that the CM was absorbed mainly during injection. Ioxaglate concentrations rose more slowly in systemic plasma and lymph, and fell more slowly in the portal plasma than those of diatrizoate and iohexol, which suggests that ioxaglate was absorbed over a longer period. When outflow was impaired, ioxaglate concentrations remained on a lower level, indicating less penetration in the pancreatic parenchyma. CM absorption varied markedly within each group, suggesting that variations in intraductal pressure and flow are more important in absorption than the type of CM used.