Effect of prior thermal stress on the severity of caerulein induced pancreatitis: 12 hours after exposure to thermal stress, pancreatitis was induced by caerulein administration and its severity was quantitated, as described in the text, in control animals, in control animals exposed to hyperthermia, in rats given caerulein, and in rats given caerulein after prior exposure to hyperthermia. Results are expressed as a per cent of the increase noted in non-stressed animals given caerulein (that is, maximal increase). Results represent mean (SEM) values for at least three animals at each time point. *Significantly different (p<0.05) from non-stressed caerulein treated rats. MPO, myeloperoxidase.