Beneficial effects of vasodilators in preventing severe acute pancreatitis shock.

Objectives: To investigate the effect of treatment with several vasodilatory substance on the changes in mean arterial pressure (MAP) of severe acute pancreatitis.

Methods: Pancreatitis was induced in rats by 5% sodium taurocholate retrograde infusion through the pancreatic duct, which produces a significant decrease in arterial blood pressure.

Results: Three hours after the induction of pancreatitis, a fall of approximately 25 mm Hg in MAP was observed, with no changes of MAP in untreated controls. The administration of the nitric oxide synthesis inhibitor, N-nitro-L-arginine methyl ester (25 mg/kg), previously to the induction of pancreatitis, produced a marked fall in MAP leading to the death of all the animals. When several vasodilatory substances, S-nitroso-N-acetylpenicillamine (200 microg x kg x h), calcitonin gene-related peptide (10 microg/kg), and vasoactive intestinal polypeptide (8 microg x kg x h) were administered previously to the induction of pancreatitis, the MAP fall induced by pancreatitis was not observed. The improvement of physiological conditions observed in vasodilator-treated animals is in agreement with histological data, which show only minor structural changes in the pancreas from these animals, in contrast with the severe alterations observed in untreated pancreatitic rats.

Conclusion: : Vasodilation confers protection against the systemic circulatory derangement derived from the development of severe acute pancreatitis.