[Effect of Jiangtang Xiaozhi Tablet on Insulin Resistance KK-AY Transgenic Mice Model of Diabetes Mellitus].

Abstract

Objective To observe effects of Jiangtang Xiaozhi Tablet (JTXZT) on homeostasis model of assessment for insulin resistance index (HOMA-IR) , insulin sensitivity index ( ISI) , expres- sions of insulin (INS) and insulin receptor (InsR) in pancreas tissues of KK-A(y) transgenic mice model of diabetes mellitus (DM). Methods KK-A(y) transgenic mice were fed with high fat forage to induce hyper- glycemic obese DM model. The C,7ice at same age were used as a normal control group (fed with e- qual volume of sterile water, n =11). Successful modeled 55 mice with DM obesity were divided into 5 groups by random digit table (11 in each group) , including the model group (fed with equal volume of ster- ile water, with no treatment) , the Pioglitazone Hydrochloride Tablet treatment group (8 mg/kg; as a posi- tive control group) , and JTXZT groups [high (10. 0 g crude drugs/kg) , middle (5. 0 g crude drugs/kg) and low dose (2. 5 g crude drugs/kg) ]. All medications were fed by gastrogavage, once per day for 8 succes- sive weeks. All mice were weighed and levels of random blood glucose (RBG) determined after 8 weeks of treatment. Blood was collected from ophthalmic vein. Levels of insulin (INS) , serum total cholesterol (TC) and triglyceride (TG) were detected. HOMA-IR and ISI were calculated. The morphological changes of pancreas tissues were extracted for performed pathological examinations. The expressions of INS and insulin receptor (InsR ) were measured by immunohistochemistry ( IHC ). Expressions of insulin receptorp βInsRP) and insulin receptor substrate-1 (IRS-1) in pancreas tissues were detected using Western blot. Results Compared with the normal control group, obesity, obviously increased blood glu- cose and blood lipids occurred in each group after modeling (P <0. 01). After 8 weeks of medication mice in the model group had put up body weight (P <0. 01) , blood glucose and blood lipids were kept on quite higher levels. Compared with the model group, body weight, serum levels of TG, INS, and HOMA-IR obvi- ously decreased in each JTXZT group (P <0. 05, P <0. 01). Besides, RBG decreased obviously lower in the high dose JTXZT group (P <0. 01). ISI obviously increased in low and high dose JTXZT groups (P < 0. 05, P <0. 01). Pathological results of HE staining in pancreas showed that atrophied islets with obvious- ly reduced numbers in the model group. They were sparsely distributed with reduced islet density.-Islet cells were compensatively hypertrophy, with degenerated vacuoles. Apoptosis of islet cells could also be seen in the model group, manifested as swollen cytoplasm and paryopyknosis. Islet number was obvious- ly increased in high and middle dose JTXZT groups, with reduced apoptosis and degenerated cells. Re- sults of IHC assay showed, as compared with the normal control group, the grey values of INS and InsR were significantly decreased in the model group (P <0. 01). Compared with the model group, IOD values of INS and InsR (IOD) were significantly increased in each JTXZT group (P <0. 05, P <0. 01). Results from Western blot showed that protein expressions of InsRP βnd IRS-1 were obviously decreased in the model group, as compared with the normal control group (P <0. 01). Compared with the model group, protein expressions of InsRP βnd IRS-1 were obviously increased in each JTXZT group (P <0. 01) , but with no statistical difference as compared with the Pioglitazone Hydrochloride Tablet treatment group (P > 0. 05). Conclusions JTXZT had obvious roles in decreasing levels of blood glucose, serum lipids, and improving insulin resistance in KK-Ayt(r) ansgenic mice model with diabetic obesity. Its mechanism might involve in increasing expressions of lnsRp and IRS-1 in pancreas cells, promoting the integration of INS to its receptors, and thereby improving glucose metabolism , lipid metabolism , and IR state.