Rat Model Of Type Research Articles

Consumption of Terpenoids-Rich Padina pavonia Extract Attenuates Hyperglycemia, Insulin Resistance and Oxidative Stress, and Upregulates PPARγ in a Rat Model of Type 2 Diabetes.

Seaweeds are rich in structurally diverse bioactive compounds with promising therapeutic effects. This study aimed to isolate and identify terpenes from the brown alga Padina pavonia and to investigate its antidiabetic activity, pointing to the possible involvement of peroxisome proliferator-activated receptor (PPAR)γ. Type 2 diabetes was induced by feeding rats a high fat diet (HFD) for 4 weeks followed by injection of 35 mg/kg streptozotocin (STZ). The diabetic rats received P. pavonia extract (PPE; 50, 100 and 200 mg/kg) for 4 weeks and samples were collected for analyses. HFD/STZ-induced rats showed hyperglycemia, dyslipidemia, impaired glucose tolerance, decreased insulin, and increased HbA1c and HOMA-IR. PPE ameliorated hyperglycemia and dyslipidemia, and improved glucose tolerance and insulin sensitivity in diabetic rats. Treatment with PPE increased hepatic hexokinase activity and glycogen, suppressed glucose-6-phosphatase, fructose-1,6-biphosphatase, and glycogen phosphorylase, and attenuated oxidative stress, inflammation, and liver injury and lipid infiltration in HFD/STZ-induced rats. In addition, PPE boosted antioxidants and upregulated PPARγ gene and protein expression in the liver of diabetic rats. Phytochemical investigation resulted in the isolation of six terpenes from PPE and in silico analysis revealed their binding affinity toward PPARγ. In conclusion, P. pavonia-derived terpenes attenuated hyperglycemia, dyslipidemia, oxidative stress, and inflammation, and improved insulin sensitivity and carbohydrate metabolism in type 2 diabetic rats. These beneficial effects are mediated via PPARγ activation. However, further studies to explore the exact mechanisms underlying the antidiabetic effect of PPE are recommended.

Presence of White Matter Lesions Associated with Diabetes-Associated Cognitive Decline in Male Rat Models of Pre-Type 2 Diabetes.

BackgroundThe aim of this study was to determine the association between white matter lesions (WML) and diabetes-associated cognitive decline (DACD) in rat models of type 2 diabetes (T2DM).Material/MethodsSixty Sprague-Dawley male rats were divided into 4 groups: control, control+metformin, T2DM, and T2DM+metformin groups. The T2DM groups were fed a diet high in fat and glucose to induce impaired glucose tolerance (IGT) and then were injected with streptozotocin to induce T2DM. The Morris water maze test was used to evaluate cognitive function. Brain diffusion tensor imaging scans were performed for WML. The expression of myelin basic protein (MBP), oligodendrocyte transcription factor 1 (OLIG1), and OLIG2 (markers of brain damage and repair) was determined using immunofluorescence. After IGT, the fractional anisotropy (FA) values of the right thalamus area were significantly lower in both T2DM groups compared with controls.ResultsEight weeks after streptozotocin injection, the FA values of the thalamus were lower in the T2DM (bilateral thalamus) group and T2DM+metformin (left thalamus) group than in controls, while the FA values in the left thalamus area were lower in the T2DM+metformin group than in the control and control+metformin groups. The maze escape latency was longer and the number of rats passing through the platform was smaller in the T2DM and T2DM+metformin groups than in the control group. MBP levels were lower and OLIG1 and OLIG2 levels were higher in both T2DM groups than in controls.ConclusionsWML is associated with DACD and appears before the onset of T2DM and signs of DACD and plays a role in diabetes-associated cognitive decline. Metformin reduces WMLs but does not rescue cognitive dysfunction.

The Comparison of Green Tea Aqueous Extract and Catechin Effect on Pituitary-Gonadal Axis in Rat Models of Type 1 Diabetes

The Comparison of Green Tea Aqueous Extract and Catechin Effect on Pituitary-Gonadal Axis in Rat Models of Type 1 Diabetes

Increased inflammation, oxidative stress and a reduction in antioxidant defense enzymes in perivascular adipose tissue contribute to vascular dysfunction in type 2 diabetes

BackgroundPerivascular adipose tissue (PVAT) surrounds most large blood vessels and plays an important role in vascular homeostasis. The present study was conducted to investigate the contribution of PVAT to vascular dysfunction in a rat model of type 2 diabetes. Material and methodsSeveral in vivo parameters such as lipid profile (total cholesterol and triglyceride systemic levels), fasting glucose levels, glucose tolerance and insulin sensitivity (through glucose and insulin tolerance tests, respectively) were determined in Goto-Kakizaki (GK) diabetic rats and compared with control Wistar rats. At the vascular level, endothelial dependent and independent relaxation and contraction studies were performed in aortic rings in the absence (PVAT−) or in the presence (PVAT+) of thoracic PVAT. We also evaluated vascular oxidative stress and performed western blots, PCR and immunohistochemistry analysis of cytokines and various enzymes in PVAT. ResultsEndothelium-dependent relaxation to acetylcholine, assessed by wire myography, was impaired in GK rats and improved by the antioxidant TEMPOL and by the TLR4 inhibitor, CLI-095 suggesting an increase in oxidative stress and inflammation. In addition, vascular superoxide and peroxynitrite production was increased in the vascular wall of diabetic rats, accompanied by reduced nitric oxide bioavailability. The presence of PVAT had an anticontractile effect in response to phenylephrine in Wistar rats that was lost in GK rats. Western blot and immunohistochemistry analysis revealed that PVAT phenotype shifts, under diabetic conditions, towards a proinflammatory (with increment in CRP, CCL2, CD36), pro-oxidant (increased levels of aldose reductase, and reduced levels of antioxidant deference enzymes) and vasoconstriction state. ConclusionOur data suggest that this rat model of type 2 diabetes is associated with perivascular adipose dysfunction that contributes to oxidative stress, inflammation and endothelial dysfunction.

The Improvement of INS Gene Sequences on Rat Model of Type 1 Diabetes in Goat Milk Casein Protein Treatment, but not in Glibenclamide

This study was aimed to determine the effect of CSN1S2 protein from Etawah Crossbred goat milk for repairing DNA sequence of INS gene in T1DM rat model. We divided the experimental rats into control group, diabetes group, control with CSN1S2 protein treatment group, diabetes with CSN1S2 protein treatment group, and diabetes with glibenclamide treatment group. The dose of CSN1S2 protein and glibenclamide used was 800 mg/kg BW and 5 mg/kg BW, respectively. We isolated the DNA from rat pancreas tissue and amplified it with a specific primer of INS gene. Our study investigated that there were transition, transversion, and deletion mutation in diabetic rat. The glibenclamide administration had changed 6 point mutations in INS of the diabetic rat to normal, but it created the other 9 new mutations. The CSN1S2 protein treatment showed mutation repairing in INS of diabetes group. Consequently, CSN1S2 have potential effect as anti-diabetes and is safe to consume than glibenclamide.

A Possible Mechanism of Metformin in Improving Insulin Resistance in Diabetic Rat Models.

Background Type 2 diabetes has become one of the most common diseases worldwide, causing a serious social burden. As a first-line treatment for diabetes, metformin can effectively improve insulin resistance. It has been reported that 12α-hydroxylated BA (mainly CA) is associated with insulin resistance. The purpose of this study was to analyze the changes in CA and possible signaling mechanisms in diabetic rats after metformin intervention. Methods HepG2 cells were cultured after adding different concentrations of metformin. The cell viability was measured using CCK8 kit, and the expression of FXR, MAFG, and CYP8B1 in cells was detected by WB. The rat models of type 2 diabetes were induced by low-dose streptozotocin by feeding a high-fat diet, and the control rats (CON) were fed on normal food; the diabetic rats (DM) were given a high-fat diet without supplementation with metformin, while the metformin-treated diabetic rats (DM + MET) were given a high-fat diet and supplemented with metformin. Biochemical parameters were detected at the end of the test. Expression levels of FXR, CYP8B1, and MAFG were assessed by WB. Serum CA were measured using an enzyme-linked immunosorbent assay (ELISA). Results In HepG2 cells, metformin dose-dependently enhanced the transcriptional activity of FXR and MAFG and inhibited the expression of CYP8B1. Metformin-treated DM rats showed improved glucose and bile acid metabolism. In addition, significantly increased FXR and MAFG and decreased CYP8B1 were observed in DM + MET rats. At the same time, the CA content of metformin-treated rats was lower than that of diabetic rats. Conclusion Changes in CA synthesis after metformin treatment may be associated with inhibition of CYP8B1. These results may play an important role in improving insulin sensitivity after metformin treatment.

Acute and Direct Effects of Sodium-Glucose Cotransporter 2 Inhibition on Glomerular Filtration Rate in Spontaneously Diabetic Torii Fatty Rats.

Recent clinical studies indicate that sodium-glucose cotransporter 2 (SGLT2) inhibitors exhibit a renoprotective effect. While studies at the single nephron level suggest that direct effects of SGLT2 inhibitors on renal hemodynamics may be a possible mechanism underlying their renoprotective effect, few studies have focused on such direct effects at the whole-kidney level. In the present study, we investigated the acute and direct effect of SGLT2 inhibition on creatinine clearance, an index of whole-kidney glomerular filtration rate (GFR), in a rat model of type 2 diabetes. Twelve to fifteen-week-old male Spontaneously Diabetic Torii (SDT) fatty rats and Sprague-Dawley rats were used as diabetic animals and non-diabetic controls, respectively. Under general anesthesia, baseline urine samples were collected from the left and right ureters for 1 h. The selective SGLT2 inhibitor ipragliflozin or vehicle was subsequently administered intravenously and post-drug urine was collected for 1 h. Baseline and post-drug blood samples were collected immediately before baseline urine collection and immediately after post-drug urine collection, respectively. Plasma glucose, urine volume, urinary glucose and albumin excretion were measured, and creatinine clearance was calculated. Blood pressure and heart rate were monitored continuously throughout the experiment. A single intravenous injection of ipragliflozin increased both urine output and glucose excretion, but reduced creatinine clearance without affecting systemic blood pressure. These results suggest that SGLT2 inhibition directly reduced whole-kidney GFR, most likely due to a reduction in intraglomerular pressure, by altering local renal hemodynamics, which may contribute to the renoprotective effects demonstrated in clinical studies.

Progression of diabetic kidney disease in T2DN rats.

Diabetic kidney disease (DKD) is one of the leading pathological causes of decreased renal function and progression to end-stage kidney failure. To explore and characterize age-related changes in DKD and associated glomerular damage, we used a rat model of type 2 diabetic nephropathy (T2DN) at 12 wk and older than 48 wk. We compared their disease progression with control nondiabetic Wistar and diabetic Goto-Kakizaki (GK) rats. During the early stages of DKD, T2DN and GK animals revealed significant increases in blood glucose and kidney-to-body weight ratio. Both diabetic groups had significantly altered renin-angiotensin-aldosterone system function. Thereafter, during the later stages of disease progression, T2DN rats demonstrated a remarkable increase in renal damage compared with GK and Wistar rats, as indicated by renal hypertrophy, polyuria accompanied by a decrease in urine osmolarity, high cholesterol, a significant prevalence of medullary protein casts, and severe forms of glomerular injury. Urinary nephrin shedding indicated loss of the glomerular slit diaphragm, which also correlates with the dramatic elevation in albuminuria and loss of podocin staining in aged T2DN rats. Furthermore, we used scanning ion microscopy topographical analyses to detect and quantify the pathological remodeling in podocyte foot projections of isolated glomeruli from T2DN animals. In summary, T2DN rats developed renal and physiological abnormalities similar to clinical observations in human patients with DKD, including progressive glomerular damage and a significant decrease in renin-angiotensin-aldosterone system plasma levels, indicating these rats are an excellent model for studying the progression of renal damage in type 2 DKD.

High Energy Intake Induced Overexpression of Transcription Factors and Its Regulatory Genes Involved in Acceleration of Hepatic Lipogenesis: A Rat Model for Type 2 Diabetes.

Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by impaired insulin action and its secretion. The objectives of the present study were to establish an economical and efficient animal model, mimicking pathophysiology of human T2DM to understand probable molecular mechanisms in context with lipid metabolism. In the present study, male Wistar rats were randomly divided into three groups. Animals were fed with high fat diet (HFD) except healthy control (HC) for 12 weeks. After eight weeks, intra peritoneal glucose tolerance test was performed. After confirmation of glucose intolerance, diabetic control (DC) group was injected with streptozotocin (STZ) (35 mg/kg b.w., i.p.). HFD fed rats showed increase (p ≤ 0.001) in glucose tolerance and HOMA-IR as compared to HC. Diabetes rats showed abnormal (p ≤ 0.001) lipid profile as compared to HC. The hepatocyte expression of transcription factors SREBP-1c and NFκβ, and their target genes were found to be upregulated, while PPAR-γ, CPT1A and FABP expressions were downregulated as compared to the HC. A number of animal models have been raised for studying T2DM, but the study has been restricted to only the biochemical level. The model is validated at biochemical, molecular and histopathological levels, which can be used for screening new therapeutics for the effective management of T2DM.

Ultrastructural and Functional Changes in Liver Mitochondria in a Rat Model of Type I Diabetes Mellitus

Abstract—The characteristics of the ultrastructure and functioning of mitochondria in the liver of Sprague Dawley rats in the experimental model of type I diabetes mellitus have been investigated. It has been found that diabetes mellitus induced in response to streptozotocin administration at a dose of 75 mg/kg body weight was accompanied by disturbances in the structural organization of mitochondrial cristae and a decrease in the size of the organelles compared to the control. It has been also demonstrated that in type I diabetes the respiratory rates of liver mitochondria in metabolic states 2, 3, and 4 increase. This may be associated with an increase in the total content of fatty acids in liver mitochondria of diabetic rats. At the same time, streptozotocin-induced diabetes mellitus in rats did not affect the indices of oxidative phosphorylation efficiency (ADP/O, respiratory control ratio, and phosphorylation time) in liver mitochondria.

Dexmedetomidine hydrochloride up-regulates expression of hypoxia inducible factor-1α to alleviate renal ischemiareperfusion injury in diabetic rats

To verify whether dexmedetomidine hydrochloride (Dex) alleviates renal ischemia-reperfusion (IR) injury in diabetic rats by increasing the expression of hypoxia inducible factor-1α (HIF-1α). A rat model of type 2 diabetes mellitus was established by high-fat diet and streptozotocin injection. The rats were subjected to daily intragastric administration of 0.05 mg/kg digoxin for 7 consecutive days and intraperitoneal injection of Dex 2 h before renal IR injury induced by ligation of the bilateral renal arteries for 60 min followed by reperfusion for 120 min. After reperfusion, blood samples were taken for detection of serum creatinine (Scr) and urea nitrogen (BUN) levels. Western blotting was used to detect the expression of HIF-1α, cleaved caspase-3, Bcl-2, and Bax in the renal tissues; the expression of the HIF-1α, p-eNOS, and eNOS were detected using ELISA. The percentage of apoptotic glomerular cells was assessed using TUNEL assay. The levels of Scr, BUN, HIF-1α, p-eNOS, and eNOS and the percentage of apoptotic cells in both normal and diabetic rats increased significantly after renal IR injury (P < 0.05). The expressions of Scr, BUN, p-eNOS, and eNOS decreased while HIF-1α expression increased significantly in Dex-treated rats with renal IR injury (P < 0.05). Compared with the non-diabetic rats, the diabetic rats showed more obvious increase in the expressions of Scr, BUN, p-eNOS, and eNOS following renal IR injury. In the diabetic rats with renal IR injury, Dex treatment prior to the injury significantly lowered the expressions of Scr, BUN, p-eNOS, eNOS, cleaved caspase-3, and Bax, decreased the percentage of apoptotic cells, and increased the levels of HIF-1a and Bcl-2 (P < 0.05). Digoxin treatment significantly antagonized the effects of Dex in the diabetic rats with renal IR injury by increasing the expressions of cleaved caspase-3 and Bax, promoting glomerular cell apoptosis, and decreasing renal expressions of HIF-1 and Bcl-2 (P < 0.05). Dex alleviates renal IR injury in diabetic rats probably by inhibiting renal expression of HIF-1α and glomerular cell apoptosis.

Potential impact of exercise versus irisin on hypertension, and visceral adiposity in a rat model of type 2 diabetes mellitus

Background: Type 2 diabetes mellitus (T2DM) is associated with obesity, insulin resistance, and hypertension. Exercise may play important role in combating obesity and diabetic complications. Irisin is a newly discovered exercise-induced myokine. Its role in mediating the beneficial effects of exercise is questionable. Aim: The present study was performed to reveal the beneficial effects of moderate-intensity exercise on diabetic-induced visceral obesity, and hypertension in a rat model of T2DM, as well as the potential role of irisin relative to exercise and the mechanisms-involved. Materials and methods: Rats were allocated into 4 groups; control, type 2 diabetes mellitus (T2DM), exercise-T2DM and irisin-T2DM groups. Body weight (BW), body mass index (BMI), perirenal fat (PF), systolic (SBP), diastolic (DBP), and mean blood pressures (MBP), fasting blood glucose (FBG), insulin, nitrite, and HOMA-insulin resistance (IR) and histology of adipose tissue were determined. Results: Exercise attenuated the adverse effects of T2DM, whereas PF, PF index, serum nitrite, plasma insulin, and HOMA-IR comparable to controls; however, FBG, SBP, DBP and MBP still significantly higher. Partial browning of white adipose tissue demonstrated. Irisin-T2DM rats showed a remarkable effect compared to exercise intervention documented by a reduction in BW, BMI, PF, PF index, DBP, FBG, and insulin, with increase in nitrite, and complete browning of adipose tissue. Conclusion It is concluded that exercise and irisin treatment can improve visceral adiposity and hypertension; however, the protective effect of irisin is more obvious. These data suggest irisin as a potential new strategy to combat obesity and hypertension in diabetic patients.

Stevia rebaudiana Bertoni Leaves Extract as a Nutraceutical with Hypoglycemic Activity in Diabetic Rats

BACKGROUND: The prevalence of diabetes mellitus is growing every year, including in Indonesia. Medicinal herbs were used empirically for lowering blood glucose. One of potential herb to have hypoglycemic activity is Stevia. Stevia rebaudiana Bertoni leaves contain stevoside, a natural, low-calorie sweetener that is 300 times sweeter than saccharose. In this study, we aimed to explore the hypoglycemic activity of S. rebaudiana Bertoni leaves extract in a rat model of type 2 diabetes mellitus (T2DM). METHODS: Male Wistar rats were feed high-fat, high-carbohydrate feed and sugar solution for 74 days to induce a diabetic rat model. The animals were then divided into five groups consisting of a negative control group treated with 2% Pulvis Gom Arabicum; a positive control group treated with Metformin 45 mg/kg body weight (BW); and three test groups treated with aqueous extract of S. rebaudiana Bertoni leaves at doses of 3.125, 6.25 and 12.5 mg/kg BW for 36 days. Blood glucose was measured on days 14, 28 and 36.RESULTS: The results showed that blood glucose levels over 36 days were significantly (p=0.043) lower in the group treated with S. rebaudiana Bertoni leaves extract. Further Newman-Keuls analysis suggested that the hypoglycemic activity of S. rebaudiana Bertoni leaves extract was dose-dependent. CONCLUSION: Our results indicate that S. rebaudiana Bertoni leaves extract has a potential role as a hypoglycemic agent in the treatment of T2DM.KEYWORDS: Stevia rebaudiana Bertoni, nutraceuticals, hypoglycemic, diabetic rats

High Expression of Complement Components in the Kidneys of Type 2 Diabetic Rats With Diabetic Nephropathy.

Background: Diabetic nephropathy (DN) is the leading cause of end-stage failure of the kidneys; however, its pathogenesis remains unknown. This study assessed the expression of complement components in the kidneys of rats with type 2 DN to investigate their role in DN.Methods: A rat model of type 2 DN was induced by a high-fat diet combined with low-dose streptozotocin. Blood glucose, fasting insulin levels, insulin resistance index, and 24-h urinary albumin excretion (UAE) were measured. Renal tissue morphological features were observed. The mesangial index and arteriosclerosis index were calculated. Immunohistochemistry and western blot were used to measure the expression of complement components in the kidneys.Results: The kidney weight: body weight (mg/g) ratio in the DN group was significantly greater than those in the control and diabetes mellitus (DM) groups. The arteriosclerosis index, mesangial index, and tube area percentage in the DN group were significantly higher than those in the control and DM groups, but these parameters did not significantly differ between the control and DM groups. The expression of the complement components C1q, mannose-binding lectin (MBL), mannan-binding lectin-associated serine protease (MASP)-2, B factor, C3, and C5b-9 in the DN group was significantly higher than that in the control and DM groups but did not significantly differ between the control and DM groups. Most of the complement components were mainly expressed at the renal tubular site. Correlation analysis showed that 24-h UAE were positively correlated with C1q, MBL, MASP-2, B factor, and C5b-9 expression. MI was positively correlated with MBL, B factor, C3, and C5b-9 expression. AI was positively correlated with C1q, MBL, MASP-2, and B factor expression.Conclusion: Complement components including C1q, MBL, MASP-2, B factor, C3, and C5b-9, were highly expressed in the kidneys of type 2 diabetic rats with DN. Most of the complement components were mainly expressed in the renal tubules. High expression of complement components was found to be associated with the progress of DN. Our study suggests that complement system activation is a progressive factor in type 2 diabetic nephropathy. Inhibition of pathological complement activation may be a promising therapeutic strategy for DN.

Impairment of cholinergic bladder contractility in rat model of type I diabetes complicated by cystitis: Contribution of neurotransmitter-degrading ectoenzymes

Parasympathetic regulation of urinary bladder contractions primarily involves acetylcholine release and activation of detrusor smooth muscle (DSM) muscarinic acetylcholine (mACh) receptors. Co-release of ATP and activation of DSM purinergic P2X1-receptors may participate as well in some species. Both types of neuromuscular transmission (NMT) are impaired in diabetes, however, which factors may contribute to such impairment remains poorly understood. Here by using rats with streptozotocin(STZ)-induced type I diabetes (8th week after induction) we show that contribution of atropine-sensitive m-cholinergic component to the contractions of urothelium-denuded DSM strips evoked by electric field stimulation (EFS) greatly increased when diabetic bladders presented overt signs of accompanying cystitis. Modeling of hemorrhagic cystitis alone in control rats by cyclophosphamide injection only modestly increased m-cholinergic component of EFS-contractions. However, exposure of DSM strips from control animals to acetylcholinesterase (AChE) inhibitor, neostigmine (1–10 μM) largely reproduced alterations in EFS contractions observed in diabetic DSM complicated by cystitis. Ellman's assay revealed statistically significant 31% decrease of AChE activities in diabetic vs. control DSM. Changes in purinergic contractility of diabetic DSM were consistent with altered P2X1-receptor desensitization and re-sensitization. They could be mimicked by pharmacological inhibition of ATP-degrading ecto-ATPases with ARL 67156 (50 μM), pointing to compromised extracellular ATP clearance as underlying reason. We conclude that decreased AChE activities associated with diabetes and likely cystitis provide complementary factor to the described in literature altered expression of mACh receptor subtypes linked to diabetes as well as to cystitis to produce dramatic modification of cholinergic NMT.

Conserved properties of genetic architecture of renal and fat transcriptomes in rat models of insulin resistance.

ABSTRACTTo define renal molecular mechanisms that are affected by permanent hyperglycaemia and might promote phenotypes relevant to diabetic nephropathy, we carried out linkage analysis of genome-wide gene transcription in the kidneys of F2 offspring from the Goto-Kakizaki (GK) rat model of type 2 diabetes and normoglycaemic Brown Norway (BN) rats. We mapped 2526 statistically significant expression quantitative trait loci (eQTLs) in the cross. More than 40% of eQTLs mapped in the close vicinity of the linked transcripts, underlying possible cis-regulatory mechanisms of gene expression. We identified eQTL hotspots on chromosomes 5 and 9 regulating the expression of 80-165 genes, sex or cross direction effects, and enriched metabolic and immunological processes by segregating GK alleles. Comparative analysis with adipose tissue eQTLs in the same cross showed that 496 eQTLs, in addition to the top enriched biological pathways, are conserved in the two tissues. Extensive similarities in eQTLs mapped in the GK rat and in the spontaneously hypertensive rat (SHR) suggest a common aetiology of disease phenotypes common to the two strains, including insulin resistance, which is a prominent pathophysiological feature in both GK rats and SHRs. Our data shed light on shared and tissue-specific molecular mechanisms that might underlie aetiological aspects of insulin resistance in the context of spontaneously occurring hyperglycaemia and hypertension.

Glucose‐Responsive Composite Microneedle Patch for Hypoglycemia‐Triggered Delivery of Native Glucagon

Insulin-dependent patients with diabetes mellitus require multiple daily injections of exogenous insulin to combat hyperglycemia. However, administration of excess insulin can lead to hypoglycemia, a life-threatening condition characterized by abnormally low blood glucose levels (BGLs). To prevent hypoglycemia associated with intensive insulin therapy, a "smart" composite microneedle (cMN) patch is developed, which releases native glucagon at low glucose levels. The cMN patch is composed of a photo-crosslinked methacrylated hyaluronic acid (MeHA) microneedle array with embedded multifunctional microgels. The microgels incorporate zwitterionic moieties that stabilize loaded glucagon and phenylboronic acid moieties that provide glucose-dependent volume change to facilitate glucagon release. Hypoglycemia-triggered release of structurally unchanged glucagon from the cMN patch is demonstrated in vitro and in a rat model of type 1 diabetes (T1D). Transdermal application of the patch prevented insulin-induced hypoglycemia in the diabetic rats. This work is the first demonstration of a glucose-responsive glucagon-delivery MN patch for the prevention of hypoglycemia, which has a tremendous potential to reduce the dangers of intensive insulin therapy and improve the quality of life of patients with diabetes and their caregivers.

A Study of Kir6.2 Gene Sequence in Rat Model of Type 2 Diabetes Mellitus Treated by CSN1S2 Protein of Etawah Crossbred Goat Milk

Type 2 diabetes mellitus (T2DM) is a metabolic disease characterized by hyperglycemia. High blood glucose levels in T2DM patients are treated by sulfonylurea. However, the long-term use of sulfonylurea can affect the regulation of glucose homeostasis and cause hypoglycemia. The cascade gene associated with the hypoglycemia is Kir6.2, a constituent of ATP-sensitive potassium channel (KATP), in the neuron. Kir6.2 mutations cause dysregulation of insulin secretion by pancreatic beta cells and glucagon secretion by pancreatic alpha cells. The aim of this study was to analyze the effect of CSN1S2 protein of etawah crossbred goat milk on Kir6.2 gene sequences in the rat model of T2DM. The experimental animals used were male Wistar rats (Rattus norvegicus) which were divided into two major groups, namely control group and T2DM group. Each group was administrated by CSN1S2 protein with the dose of 375 mg/kg BW, 750 mg/kg BW, 1500 mg/kg BW, and without CSN1S2 protein administration. Each group was replicated three times. DNA was isolated from the rat brain. Kir6.2 gene was amplified by using specific primers. PCR products were purified and sequenced by using ABI 3730xl DNA Sequencer. DNA sequences were analyzed by using MEGA7 software. Amplification of the Kir6.2 gene produced 1173 bp DNA. There was no change in the Kir6.2 sequence in all treatments. The 25 mg/kg BW dose of streptozotocin had no effect on Kir6.2 gene sequence in the rat brain. This study also showed that administration of CSN1S2 protein at the dose of 375 mg/kg BB, 750 mg/kg BW, and 1500 mg/kg BW did not cause mutations in the Kir6.2 gene in the brain of the rat model of T2DM.

Effect of Irbesartan on Oxidative Stress and Serum Inflammatory Factors in Renal Tissues of Type 2 Diabetic Rats.

To determine the effect of irbesartan on the activity of oxidative stress parameters of glutathione (GSH), superoxide enzyme (SOD) and malondialdehyde (MDA), and concentration of serum inflammatory factors of macrophage chemokine-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1) and tumor necrosis factor alpha (TNF-∝) in the renal tissue of type 2 diabetic rats. An experimental study. The First People's Hospital of Ningyang County, Shandong Province, China, from April 2017 to March 2018. Thirty healthy male Sprague Dawley rats were randomly divided into a normal control group, a diabetic model group, and an irbesartan treatment group, 10 in each group. Rat models of type 2 diabetes were prepared by highsugar high-fat diet with low-dose streptozotocin injection. Changes in blood glucose and lipids, serum GSH, SOD, MDA, MCP-1, ICAM-1, and TNF-∝ levels were determined. Levels of FBG, TC, TG and LDL, activity of GSH, SOD and MDA, and levels of serum MCP-1, ICAM-1 and TNF-∝ among three groups were statistically significant (all p < 0.001). Compared with the diabetic model group, FBG, TC, TG and LDL levels, MDA activity, MCP-1, ICAM-1 and TNF-∝ levels all decreased in rats of the irbesartan treatment group (all p <0.001), and both GSH and SOD activity increased (both p<0.001). Irbesartan can improve blood glucose and lipid levels in type 2 diabetic rats, and reduce renal damage by improving oxidative stress and inhibiting the release of inflammatory cytokines.

GC/MS-based metabolomics strategy to analyze the effect of exercise intervention in diabetic rats.

Metabolomics was used to explore the effect of exercise intervention on type 2 diabetes. The rat model of type 2 diabetes was induced by an injection of streptozocin (30 mg/kg), after fed with 8-week high-fat diet. The rats were divided into three groups: the control group, the diabetic model group (DM) and the diabetes + exercise group (DME). After exercise for 10 weeks, blood samples were collected to test biomedical indexes, and 24-h urine samples were collected for the metabolomics experiment. In the DME group, fasting blood glucose (FBG), both total cholesterol (TC) and total plasma triglycerides (TG), were decreased significantly, compared with those in the DM group. Based on gas chromatography-mass spectrometry (GC/MS), a urinary metabolomics method was used to study the mechanism of exercise intervention on diabetes mellitus. Based on the principal component analysis (PCA), it was found that the DM group and control group were separated into two different clusters. The DME group was located between the DM group and the control group, closer to the control group. Twelve significantly changed metabolites of diabetes mellitus were detected and identified, including glycolate, 4-methyl phenol, benzoic acid, 1H-indole, arabinitol, threitol, ribonic acid, malic acid, 2,3-dihydroxy-butanoic, aminomalonic acid, l-ascorbic acid and 3-hydroxy hexanedioic acid. After exercise, seven metabolites were significantly changed, compared with the control group, the relative contents of benzoic acid, aminomalonic acid, tetrabutyl alcohol and ribonucleic acid in the diabetic exercise group decreased significantly. The relative contents of 2,3-dihydroxybutyric acid, l-ascorbic acid and 3-hydroxy adipic acid increased significantly. l-ascorbic acid and aminomalonic acid which related with the oxidative stress were significantly regulated to normal. The results showed that exercise could display anti-hyperglycemic and anti-hyperlipidemic effects. The exercise had antioxidation function in preventing the occurrence of complications with diabetes mellitus to some extent. The work illustrates that the metabolomics method is a useful tool to study the mechanism of exercise treatment.