Objective: To evaluate the inhibitory effect of statins on glucose-stimulated insulin secretion (GSIS) of pancreatic islet in rat and to explore its mechanisms.
Methods: According to the average volume, freshly isolated or 24-hour cultured pancreatic islets were randomly divided into control group (incubated with Kreb-Ringer bicarbonate buffer), the atorvastatin group (incubated with 100 µmol/L atorvastatin), the fluvastatin group (incubated with 100 µmol/L fluvastatin) and the pravastatin group (incubated with 100 µmol/L pravastatin). Stimulated by 2.8, 5.5, 11.1, 16.7 mmol/L and 25.0 mmol/L glucose respectively, the effect of 100 µmol/L statins on ATP content and GSIS was compared in the four groups. GSIS was performed by the 37°C bath incubation method and ATP content was measured by chemiluminescence method.
Results: Incubated with 100 µmol/L atorvastatin for 30 minutes, in the presence of 16.7 mmol/L glucose, the ATP content [(9.54 ± 1.64) pmol/islet vs (12.33 ± 1.89) pmol/islet] and GSIS (1.60 ± 0.21 vs 2.39 ± 0.30) were significantly reduced in comparison with the control group (P < 0.05). Cultured with 100 µmol/L fluvastatin for 24 hours, the ATP content [(10.24 ± 2.01) pmol/islet vs (12.31 ± 2.16) pmol/islet] and GSIS (3.12 ± 0.32 vs 4.17 ± 0.37) were all significantly decreased at the higher glucose concentration of 16.7 mmol/L (P < 0.05).
Conclusion: Atorvastatin and fluvastatin may inhibit GSIS by decreasing ATP content in pancreatic islet and the inhibitory effect is related to the strength of its lipophilicity.