Exocrine pancreatic tissue from 65 male Sprague-Dawley rats was studied by light and electron microscopy to determine if acute lethal and sublethal alterations seen in the human exocrine pancreas following shock could be duplicated in an animal model. Two models were used: one in which 50% of the blood was withdrawn via cardiac puncture with no reinfusion and another in which the animal was subjected to a hypovolemic episode (40 mm Hg) for 60 minutes, with reinfusion of the blood. Animals were killed at various intervals, and pancreatic tissue was sampled for morphological study. No differences were seen between experimental and control animals by light microscopy. The main subcellular alteration seen using these models was the formation of numerous autophagic vacuoles. From these studies it appears that the alterations seen in the human pancreas in shock can be duplicated in the rat and that a shock model that involves removal of more than 50% of the animal's blood volume is necessary to cause irreversible cell damage to the exocrine pancreas.