Abstract： Objective To investigate the effects of different doses of obestatin on amylase secretion of pancreatic acinar and lobules of rats in vitro.Methods Pancreatic acinar cells of rats were separated in vitro and incubated with different doses of obestatin (0,0.1,1,10,30 nmol/L) for 1h,another group of pancreatic acinar ceils was incubated with obestatin for 30 min,then was incubated with 100 pmol/L CCK-8 for another 30 min.Pancreatic lobules,which containing intrapancreatic nerve terminals and islets,were prepared and were incubated with different concentrations of obestatin for 30 min at 37℃ with or without 75 mmol/L KCl.Amylase levels in the supernatants,acinar cells and pancreatic lobules were calculated as a percentage of total amylase content.Results Obestatin (0,0.1,1,10,30 nmol/L) produced no significant change in basal amylase release of acinar cells [ (3.48 ± 1.44) ％,(3.70 ±- 1.39) ％,(3.36 ± 1.24) ％,(3.86 ± 1.41 ) ％,(4.54 ± 2.01 ) ％ ].CCK-8 significantly increased amylase release of acinar cells [ ( 13.84 ± 2.63 ) ％ vs (3.48 ± 1.44)％,P ＜0.05],but obestatin (0.1,1,10 nmol/L) has no effect on the amylase release inducedby CCK-8 [(14.55 ± 1.7)％,(13.79 ± 1.81)％,(14.39 ± 1.12)％].Obestatin (0.1,1,10,30 nmol/L) did not affect the amylase release of pancreatic lobuole.KCl significantly increased anylase release,which was ( 1.84 ± 0.29 ) folds higher than that of control group ( P ＜ 0.05 ),but obestatin has no effect on the amylase release induced by KCl,which were (2.01 ± 0.30 ),( 1.89 ± 0.41 ),( 1.74 ± 0.14 ),( 1.88± 0.33) folds higher than those of control group.Conclusions Exogenous obestatin has no effects on pancreatic exocrine of acinar cells and lobules of rats in vitro and cannot block or assist the increased amylase release induced by CCK-8 or KCl.