Animals ; Cochlea ; pathology ; ultrastructure ; Diabetes Mellitus, Experimental ; pathology ; Male ; Mitochondria ; pathology ; ultrastructure ; Rats ; Rats, Sprague-Dawley

The aim of the present study was to explore the role of orphan G protein-coupled receptor 55 (GPR55) in diabetic gastroparesis (DG). Streptozotocin (STZ) was used to mimic the DG model, and the body weight and blood glucose concentration were tested 4 weeks after STZ injection (i.p.). Electrogastrogram and phenolsulfonphthalein test were used for detecting gastric emptying. Motilin (MTL), gastrin (GAS), vasoactive intestinal peptide (VIP), and somatostatin (SS) levels in plasma were determined using radioimmunology. Real-time PCR and Western blot were applied to identify the expression of GPR55 in gastric tissue, and immunohistochemistry was used to detect the distribution. The effect of lysophosphatidylinositol (LPI), an agonist of GPR55, was observed. STZ mice showed increased blood glucose concentration, lower body weight, decreased amplitude of slow wave, and delayed gastric emptying. LPI antagonized these effects of STZ. Compared to the control group, STZ caused significant decreases of MTL and GAS levels (P < 0.01), as well as increases of SS and VIP levels (P < 0.01). The changes of these hormones induced by STZ were counteracted when using LPI. GPR55 located in mice stomach, and it was up-regulated in DG. Although LPI showed no effects on the distribution and expression of GPR55 in normal mice, it could inhibit STZ-induced GPR55 up-regulation. These results suggest GPR55 is involved in the regulation of gastric movement of DG, and may serve as a new target of DG treatment. LPI, an agonist of GPR55, can protect against STZ-induced DG, and the mechanism may involve the change of GPR55 expression and modification of gastrointestinal movement regulating hormones.
Animals ; Diabetes Mellitus, Experimental ; metabolism ; pathology ; Gastroparesis ; metabolism ; pathology ; Lysophospholipids ; pharmacology ; Mice ; Receptors, Cannabinoid ; metabolism

Diabetes patients tend to have the gastrointestinal motility disorder. Although the relationship between the motility disorder and both the neurons and Cajal cells in the enteric nervous system (ENS) is well established, little is known about the role of enteric glial cells (EGCs) in gastric motility in diabetes. This study aimed to examine the expression of the glial marker S100B and morphology of EGCs in gastric tissues and the relationship between activated EGCs and the damage of gastric emptying in diabetic models. The diabetic model of rat was induced with 1% streptozotocin (STZ). The model rats at 7-14 days and at 56-63 days were defined as early diabetic rats and advanced diabetic rats, respectively, and normal rats at the two time periods served as their corresponding controls. The gastric emptying rate of the rats was tested by using the phenol red solution. The ultrastructure of EGCs in the gastric antrum was observed by the transmission electron microscopy, and the expression of S100B in the myenteric plexus was immunohistochemically detected. The results showed that the gastric emptying rate was significantly increased in the early diabetic rats and decreased in the advanced diabetic rats when compared with their corresponding control rats (P<0.01 for both). The ultrastructure of EGCs was mostly normal in both the early diabetic and control groups. Vacuolization of mitochondria and expansion of endoplasmic reticulum occurred in both the advanced diabetic group and its control group, and even the structure of smooth muscle cells and intestinal neurons was destroyed in the advanced diabetic group. The expression level of S100B in the advanced diabetic group was significantly decreased compared with its control group (P<0.05). It was obviously increased in the early diabetic control group when compared with the advanced diabetic control group (P<0.05). However, there was no significant difference in the S100B expression between the early diabetic group and its control group (P>0.05). The findings suggested that the gastric motility dysfunction in diabetes may be associated with the changes of morphology and number of EGCs in the myenteric plexus.
Animals ; Diabetes Mellitus, Experimental ; pathology ; Gastrointestinal Motility ; physiology ; Male ; Neuroglia ; pathology ; Rats ; Rats, Sprague-Dawley

Animals ; Carbon Tetrachloride Poisoning ; Diabetes Mellitus, Experimental ; complications ; Liver Cirrhosis, Experimental ; chemically induced ; complications ; pathology ; Male ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the early pathological changes of KKAy mouse model of type 2 diabetes.

METHODSFive male KKAy mice and six C57BL mice each were studied at the age of 8, 16, 20 and 24 weeks. With each mouse a 24-hour urine collection was made for the tests of proteinuria. Plasma insulin, lipids, serum creatinine and urea were also measured. Renal tissues were observed to assess glomerular and tubulointerstial pathology.

RESULTSThe KKAy mice developed hyperglycemia, hyperinsulinemia and obesity by 16 weeks of age (P < 0.01). The proteinuria increased with the increasing of age (P < 0.005), but there were no changes in control. The glomerular hypertrophy was observed in KKAy mice at the age of 16 weeks. Computer map analysis system (CMIAS) indicated the expansion of mesangial matrix in KKAy mice with ageing. There was significant tubular dilation, accompanied with focal tubular atrophy and interstitial fibrosis. On electron microscopy, GBM undergo progressive thickening (P < 0.01), accompanied with podocytes fusion and increasing of proteinuria.

CONCLUSIONSKKAy mice developed hyperglycemia, hyperinsulinemia and obesity after 16 weeks, with proteinuria, mesangial matrix accumulation, GBM thickening and tubular dilation. It was considered a good animal model for the early pathology changes of DN.

Animals ; Diabetes Mellitus, Experimental ; pathology ; Diabetes Mellitus, Type 2 ; pathology ; Diabetic Nephropathies ; pathology ; Disease Models, Animal ; Kidney ; pathology ; Male ; Mice ; Mice, Inbred C57BL

Objective To investigate the sequential changes of the number of neutrophils and myofibroblasts during diabetic wound healing, and discuss its application value in wound age estimation. Methods Diabetic DB mice and mice of the same age in the normal control group were selected, a wound healing model was established, wound samples were taken at different time points, while the number of neutrophils and myofibroblasts during diabetic wound healing were determined by immunohistochemical staining technique. Results The number of infiltrated neutrophils in the wounds of control and diabetic groups reached the peak respectively at 12 h and 5 d after injury. Compared with the control group, the number of neutrophils in the diabetic group decreased significantly from 6 h to 1 d after injury, but increased markedly from 5 d to 14 d. From 5 d to 10 d after injury, the average number of neutrophils at high magnification in wounds of the diabetic group was over 30, while that of neutrophils in wounds of the control group was less than 20. Myofibroblasts appeared in wounds from 3 d to 14 d after injury in the control group and from 5 d to 14 d after injury in the diabetic group. The difference in the number of myofibroblasts in wounds between control group and diabetic group from 3 to 7 d after injury had statistical significance. Conclusion In comparison with normal wound healing, the number of neutrophils and myofibroblasts during diabetic wound healing shows different sequential changes. The results of this study can provide reference for wound age estimation of patients with severe diabetes.
Animals ; Diabetes Mellitus, Experimental/pathology* ; Mice ; Myofibroblasts ; Neutrophils ; Wound Healing/physiology*

OBJECTIVE: To analyze the changes of blood biochemical index and the pathological changes of myocardium and kidney in type 2 diabetic mouse at different time points, which can provide the basis for the selection of type 2 diabetic modeling time for later research. METHODS: After 6 weeks of feeding with high-fat diet, 24 healthy male ICR mice were injected with streptozocin (STZ, 30 mg/kg) intraperitoneally for 5 days to establish diabetic models. After 9 days, a random blood glucose ≥ 11.1 mmol / L was measured as diabetic mice. 4, 6 and 8 weeks after successfully preparing the diabetic mouse, 8 diabetic mice (a group)would be sacrificed each time. Then the biochemical and pathological conditions were analyzed: ① the indexes of heart and kidney were calculated. ②the serum levels of creatine kinase (CK), lactate dehydrogenase (LDH), creatinine (Cr) and blood urine nitrogen (BUN) were determined. ③ Histopathological changes of myocardium and renal tissues were observed by hematoxylin and eosin (HE) staining. Masson staining was used to observe the fibrosis of myocardium. PAS staining was adopted to observe the pathological changes of renal tissue. In addition, 8 ICR male mice were taken as the control group. RESULTS: At the 4, 6 and 8 week, cardiac organ coefficient, the values of LDH and CK were all increased compared with the control group. Cardiomyocyte hypertrophy and myocardial fibrosis could be observed. Renal organ coefficient, the values of Cr and BUN were increased. Glomerular hypertrophy, basement membrane thickening and atrophy could be perceived. CONCLUSION At the 6 week, related biochemical and pathological changes in diabetic mice were comparatively obvious and breeding time was relatively short. Thus, 6 weeks after the preparation of the diabetic mice would be the optimal time for type 2 diabetes mellitus modeling, proper for inventions of drugs and other research purposes including pathology, physiology, biochemistry, etc.
Animals ; Diabetes Mellitus, Experimental ; pathology ; Diabetes Mellitus, Type 2 ; pathology ; Disease Models, Animal ; Kidney ; pathology ; Male ; Mice ; Mice, Inbred ICR ; Streptozocin

This study aimed to explore the cognitive dysfunction of and hippocampal neuron damage to Wistar rats with STZ-induced diabetes at different morbidity time. All Wistar rats in the tests received intraperitoneal injections of streptozotocin (STZ; 60 mg/kg) to induce type 1 diabetes. The concentration of blood glucose and the body weight were investigated, the cognitive ability of rats was assessed using a standardized Y-maze, and the apoptotic neurons in the CA1 of the hippocampus were also examined by using the HE staining. While the sickening time was prolonged, the blood glucose concentration of the experimental rats increased continuously and the body weight decreased. On the 70th day after STZ administration, the neuronal loss in the hippocampal CA1 region increased and the working errors increased in rats with the diabetes. The results showed that Wistar rats could complicate with diabetic encephalopathy in 70 days after injection of STZ for inducing the diabetes.
Animals ; Blood Glucose ; Body Weight ; CA1 Region, Hippocampal ; cytology ; pathology ; Cognition ; Cognition Disorders ; physiopathology ; Diabetes Mellitus, Experimental ; physiopathology ; Diabetes Mellitus, Type 1 ; Neurons ; pathology ; Rats ; Rats, Wistar ; Streptozocin

AIMTo clarify the ultrastructural changes of penile tunica albuginea (TA) in streptozotocin (STZ)-induced diabetic rats.

METHODSIntraperitoneal injection of STZ was used to induce diabetes mellitus (DM) in 12 Sprague Dawley rats. Ten rats (age and weight-matched) were used as control. Blood samples from the tail snips of the rats were used for the determination of serum glucose levels with SureStep Plus Blood Meter. At week 4 and 10 after the injection, half of the rats in each group were sacrificed and penile samples were obtained from the middle third of the penile shaft for the examination of TA under scanning electron microscopy.

RESULTSIn the diabetic group, the serum glucose levels were higher (P<0.01 at both time points) and the TA were thinner (P<0.05) than those of the controls. In the control group, the fibers of TA were rich and arranged regularly and undulated, while in the diabetic group, the fibers were diminished, lost the undulations and were arranged irregularly.

CONCLUSIONIn rats, DM appeared to impair the penile TA ultrastructures and this impairment could contribute to diabetic erectile dysfunction in part by impairing the veno-occlusive function.

Animals ; Blood Glucose ; metabolism ; Diabetes Mellitus, Experimental ; pathology ; Male ; Microscopy, Electron, Scanning ; Penis ; pathology ; ultrastructure ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the relationship between the degree of neovascularization and non-healing wounds in scalded rats with diabetic mellitus.

METHODSSixty Sprague-Dawley rats were randomly divided into control group (C, n = 30, with treatment of isotonic saline) and streptozocin (STZ)-induced diabetic group (D, n = 30, with treatment of STZ), and then they were inflicted with 20% TBSA deep partial thickness scald. Wound specimens were harvested immediately after scald and on 1, 3, 7, 10, 14, 21 post scald days (PSD) to observe histological changes, and wound healing rates were calculated. Degree of neovascularization in wound (labeled with blue microsphere) and the quantity of vascular endothelial cells (labeled with red CD31) were also measured by double-labeling immunofluorescence.

RESULTSCompared with those in C group, Wound healing rate and histological value scores were lowered, and the degree of neovascularization was abated markedly at each time point. The degree of neovascularization in D group (12.00 +/- 1.40) was obviously lower than that in C group on 7 PSD (60.00 +/- 3.00, P <0.01). There was no obvious difference in the number of vascular endothelial cells in both groups, however, the majority of endothelial cells had not formed functional capillaries in D group.

CONCLUSIONVascular endothelial cell can proliferate actively with poor blood supply in diabetic nonhealing with deep partial-thickness scald wounds, but it is still poor in blood supply due to lack of functional capillaries.

Animals ; Burns ; pathology ; Diabetes Mellitus, Experimental ; pathology ; Neovascularization, Pathologic ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Wound Healing