Endogenous Hypertriglyceridemia Intensifies the Course of Cerulein-Induced Pancreatitis in Rat: Relation with Changes in the VLDL Composition

Abstract

Aims: To study if the course of cerulein-induced pancreatitis in rats changes in a state of triglyceride-rich lipoprotein metabolism alteration. Methods: Two groups of rats received control diet during a 90-day period (A) and sucrose-rich diet to induce endogenous hypertriglyceridemia (B). Subgroups A2 and B2 received i.p. 45 µg cerulein/kg body weight (to induce acute pancreatitis). Histological examination of pancreas tissue, serum pancreatic lipase, lipoprotein profile and VLDL chemical composition were assessed. Then, pancreatic lipase hydrolytic activity on VLDL-triglycerides was evaluated in vitro. Results: Cellular vacuolization was observed in all of the cerulean-injected rats, but only in subgroup B2 fat necrosis was present. Serum triglycerides were higher in subgroup B1 than in subgroup A1 (mean ± SEM, mg/dl 123,77 ± 25.7 vs. 65.8 ± 7, p < 0.01). Triglycerides from rats fed with sucrose-rich diet, decreased after cerulein-induced pancreatitis (80.38 ± 11.3 vs. 123,77 ± 25.7, p < 0.02). Moreover, the endogenous hypertriglyceridemic rats showed an increment of VLDL triglyceride content, which decreased when rats were injected with cerulein. A negative correlation was found between VLDL-triglyceride content and serum pancreatic lipase activity (r = 0.58, p < 0.02). The in vitro assay showed a decrease in VLDL-triglyceride content post incubation with pancreatic lipase enriched serum (mean ± SD: 59.2 ± 27.7%, p < 0.01). Conclusions: The endogenous hypertriglyceridemia intensifies the course of cerulein-induced pancreatitis and it could be related to the decrease in VLDL-triglycerides as a consequence of pancreatic lipase hydrolytic activity.