| Objective: To establish the insulin resistance and diabetes model of Banna pig byfeeding with the high-fat diet and induced with STZ, the expression of GSK-3β andcyclinD1was detected and their functions in diabetes and complications wereinvestigated, in addition, their possible relationship was deduced in this model.Methods:1. Eight male Banna miniature pigs of two-month-old were randomlydivided into two groups: normal control group (CD) and high-sucrose/high-fat dietwith streptozocin group (HFSD+STZ).2. HFSD+STZ group was fed withhigh-sucrose/high-fat diet and injected STZ resolved in citric acid buffer from theintravenous one time in the first month of experiment, then injected three times fromthe vein in the seventh month of experiment. CD group was fed with the normal basaldiet and injected the same volume of citric acid buffer without drug intervention fromthe vein. The status of eating, drinking, mental and excretion for the two groupexperimental animals was observed at any time.3. The blood samples were takenmonthly from the orbital venous sinus after fasting for12hours, the plasma glucose,TC (total cholesterol), TG (triglyceride), FINS (fasting insulin) were measured.4. Theintravenous glucose tolerance test (IVGTT) was taken in the eleventh months for thefirst time according to the early biochemical indicators and taken once again in thetwelfth months, then the animals were sacrificed and the tissue samples of skeletalmuscle, kidney, liver and pancreas were taken out. The morphology change of eachtissue sample was observed by the HE dyeing of paraffin-embedded tissue sections,and the sedimentary situation of muscle glycogen and liver glycogen was observed bythe PAS dyeing, and the ultra-structural changes of each tissue sample were observed by the transmission electron microscopy. The mRNA expressions of GSK-3β in theskeletal muscle, kidney, liver tissue and cyclinD1in the renal tissue were detected byusing the real-time quantitative PCR. The content of cyclinD1in the renal tissue wasdetected by ELISA and the protein expression of GSK-3β in the skeletal muscle,kidney, liver and pancreatic tissue was determined by Western blotting.Results:1. For HFSD+STZ group, the fasting blood glucose, total cholesterol andtriglycerides of Banna miniature pigs were increased significantly compared with CDgroup during the experiment, and their fasting serum insulin was higher than the CDgroup in the5th,6th and7th month, but lower than CD group in other months withthe significant difference.2. The pathology of kidney, liver, pancreas tissue forHFSD+STZ group changed with different extent.3. For HFSD+STZ group, themRNA and protein expression levels of GSK-3β in the skeletal muscle, kidney, livertissue and cyclinD1in the renal tissue were increased and the protein expression ofGSK-3β in the pancreas tissue were also increased compared with CD group.Conclusions:1. The insulin resistance and diabetes model of Banna pig wasestablished successfully by feeding the high-sucrose/high-fat diet and induced withthe small doses of STZ.2. The mRNA and protein expression of GSK-3β in theskeletal muscle, kidney, liver tissue and the protein expression of GSK-3β in thepancreas tissue were increased by feeding the high-sucrose/high-fat diet and inducedwith the small doses of STZ.3. The pathological changes of diabetes and kidneydisease were observed in the model of Banna pig, in which the cyclinD1wasincreased.4. From the diabetes animal model established in this study, therelationship between the expression of GSK-3β and cyclinD1is positively correlated,which is different from their relationship of negative correlation in the classical Wntpathway.Postgraduate: Su-jun Zhang (Biochemistry and Molecular Biology)Directed by Professor: Wei-dong Yin... |
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