Effects of timing of diatrizoate (water-soluble contrast medium) administration on pancreatic microcirculatory derangement in cerulein pancreatitis in rats

Objective: We investigated whether the timing of administration of contrast medium after onset of acute pancreatitis is critical in determining the ma gnitude of microcirculatory derangement, Methods: An acute pancreatitis model in male Sprague-Dawley rats (225-275 g ) was established by continuous infusion of cerulein (15 mg/kg per hour). T he mean arterial pressure was monitored continuously by means of a femoral artery catheter, Diatrizoate (Hypaque-76), a water-soluble contrast medium, was delivered through a femoral vein catheter at doses corresponding to th ose given to humans, either 1, 2, or 3 hours after pancreatitis induction. In vivo microscopy and laser-Doppler flowmetry were used to investigate mic rocirculatory derangement, The water contents of the pancreas and lung, the malondialdehyde levels of the pancreas, and the trypsinogen activation pep tide levels in the serum were measured at the end of the experiment (8 hour s after infusion of cerulein). Results: Early administration of contrast medium (1 hour after pancreatitis induction) resulted in significantly greater changes in microcirculation a nd mean arterial pressure than did late administration (2 or 3 hours after pancreatitis induction). Rats given contrast medium 1 hour after induction also had highest pancreas and lung water contents, the highest pancreas mal ondialdehyde levels, and the highest serum trypsinogen activation peptide l evels. Conclusion: These results show that a water soluble contrast medium that is often used for computed tomographic imaging of the pancreas can adversely affect the pancreatic microcirculatory parameters, such as tissue perfusion and leukocyte sticking, and hemodynamics in a cerulein-induced model of ac ute pancreatitis. Early administration seems to cause more severe derangeme nt of the pancreatic microcirculation.