The Effect Of Soybean Trypsin Inhibitor On Structure And Function And Gene Expression Profile In Pancreas Of Mice

The present study was undertaken to evaluate the effect of soybean trypsin inhibitor (STI)on structure and function in pancreas of mice during different growth periods.180clean andmale KM mice were selected and randomly divided into three groups. The first group as acontrol group was fed on control diet; the second group was fed control diet containing STI(200mg/100g diet); the third group was fed STI diet supplemented with vitamin C (1500mg/kgdiet). After1w,2w,3w,4w and5w of feeding, serum and pancreas samples were collected.Oxidant and antioxidant parameters levels, trypsin activities and hormone levels were measured.Transcription levels of genes were determined by RT-PCR. Ultrastructure of pancreas wasobserved under an electric microscope. The results showed that: Compared with the controlgroup, MDA contents were significantly increased in serum and pancreas of mice in STI group.And in five growth periods, MDA contents were increased in the first two weeks, and achievedthe maximum in the third week, then dropped; In STI+VC group, the level of oxidation wasdecreased, but its value was still significantly higher than that of control group (P <0.05).Compared with the control group, antioxidant parameters、trypsin activities and SST、INS levelsin STI group were significantly decreased (P <0.05). And in different growth stages, theseparameters were dropped in the first two weeks, achieved the minimum in the third week, thenincreased. In STI+VC group, the abilities of antioxidant defenses were enhanced, but still lowerthan that of control group (P <0.05). RT-PCR results showed that, Compared with the controlgroup, transcription levels of GSH-Px, T-SOD et al. genes mRNA in STI group were decreased.In different growth stages, the transcription levels were dropped first then increased. In STI+VCgroup, the transcription levels of those genes mRNA were increased. With the increase of STIfeeding time, the damage degree of structure in pancreas were increased then dropped. At the3rdweek, the damage degree is most serious. Oxidative damage degree of the pancreas wasweakened by vitamin C. The present study indicates that the effect of STI on antioxidantcapacity、pancreatic structure and function of mice is relative to growth periods, and this effectis the most striking in the3rdweek. In addition, vitamin C can interfere with the role of STI onthe organism and effectively improve the status of oxidative stress.The present study was undertaken to evaluate the effect of soybean trypsin inhibitor onpancreatic gene expression profile of mice.24clean and male KM mice were selected and randomly divided into two groups. The first group as a control group was fed on control diet; thesecond group was fed control diet containing STI (200mg/100g diet). These animals were fedfor three weeks. The effect of STI on gene expression of pancreas in mice was estimated bygene chip. The results showed that STI diet made genes of271up-regulated and genes of388down-regulated. Expression levels of genes related oxygen and reactive oxygen speciesmetabolism were changed. Among them, Mt3、Mt4and Ephx2genes expression level wereincreased more than2times; Sod1、Gpx4and Cat genes expression level were decreased morethan2times. Expression levels of genes related oxidoreductase activity were changed. Amongthem, Aldh3a1and Por genes expression level were increased more than2times; Sord and Cpgenes expression level were decreased more than2times; Cybb gene expression level weredecreased more than1.5times. Expression levels of genes related glutathione transferase werechanged. Gsta1、Gsta2、Gsta4、Mgst3、GSTP2genes expression level were increased more than2times. Expression levels of genes related pancreatic secretion were changed. Among them,Ins1、Ins2、Sst and Gcg genes expression level were decreased more than2times; Sstr5andAmy1genes expression level were decreased more than1.5times. The present study indicatedthat expression levels of genes in pancreas of mice were changed by STI, particularly expressionlevels of genes related oxidative stress were significant changed.