Objective To observe the sequence of fat deposit and its relationship with insulin resistance in SD rats fed by high fat diet.Methods Normal 8-week-old male SD rats were randomly divided into normal chow (NC,n=40)and high fat diet(HF,n=40)groups.Triglyceride(TG)in serum,liver and muscle were measured;glucose infusion rate(GIR)and the mRNA level of genes related to lipid metabolism in liver and muscle were determined in different stages.GIR was detected by eugiyeemic-hyperinsulinemic clamp for evaluating the insulin sensitivity.Gene expression was determined by real-time PCR.Results(1)As compared with NC group,serum TG was not increased after high fat feeding for4 and 8 weeks,it began to increase after 12 weeks [0.52(0.15-1.00) mmol/L vs O.31(0.09-0.53)retool/L, P0.05)in skeletal muscle.After 8 weeks,the expression of ACC1 in liver in HF group was increased by 20.6%,CPT-1 was decreased by 27.1%(P

OBJECTIVETo investigate the effect of beta cell lipoapoptosis after long term high-fat feeding in rats, and to investigate the relationship between oxidative stress, gene expression and beta cell lipoapoptosis.

METHODSForty-one SD male rats were randomly divided into 2 groups: high-fat diet group (HF group) and control group (NC group). At the end of 28 weeks, the levels of malondialdehyde (MDA) and glutamylcysteinylglycine (GSH) in plasma and pancreatic tissue,the early-phase insulin secretion in beta cells, the beta cell apoptosis (TUNEL technology) and the uncoupling protein 2 (UCP2) gene expression in islets were measured.

RESULTThe concentrations of MDA both in plasma and pancreatic tissue were higher in HF group than those in NC group.In contrast, The contents of GSH both in plasma and pancreatic tissue were lower in HF group. Insulin secretion response to glucose load was significantly decreased in HF group (3.0 fold Compared with 5.7 fold, P<0.01). Blood glucose levels at 3 min, 5 min and 10 min during IVGTT were significantly higher in HF group than those in NC group (P<0.05). The frequency of beta cell apoptosis was increased by 40.0% in HF group (P<0.01). The gene expression of UCP2 in islets was increased by 22.4% in HF group (P<0.01).

CONCLUSIONThe frequency of beta cell apoptosis in high-fat feeding rats is affected by oxidative stress, which results in increasing UCP2 gene expression.

Animals ; Apoptosis ; physiology ; Dietary Fats ; administration & dosage ; Insulin-Secreting Cells ; metabolism ; pathology ; Ion Channels ; genetics ; metabolism ; Male ; Malondialdehyde ; metabolism ; Mitochondrial Proteins ; genetics ; metabolism ; Oxidative Stress ; physiology ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Uncoupling Protein 2

BACKGROUNDCurrently it is unclear whether lipid accumulation occurs in a particular sequence and its relationship with whole body insulin resistance (IR). This study aimed to answer this question.

METHODSMale Sprague-Dawley (SD) rats were fed on a normal or a high-fat diet for 20 weeks. Serum triglycerides (TG), serum free fatty acids (FFA), fasting plasma glucose (FPG), and liver and skeletal muscle TG were measured. The glucose infusion rate (GIR) and mRNA levels of acetyl-CoA carboxylase (ACC) and carnitine palmitoyltransferase-1 (CPT-1) in the liver and skeletal muscle were determined at different stages.

RESULTSCompared with rats fed on the normal diet, serum FFA was not significantly increased in rats fed on the high-fat diet until 20 weeks. In contrast, liver TG was significantly increased by the high-fat diet by four weeks (20-fold; P < 0.01), and remained elevated until the end of the study. However, skeletal muscle TG was not significantly increased by the high-fat diet until 20 weeks (10.6-fold; P < 0.01), and neither was the FPG. The GIR was significantly reduced (1.6-fold; P < 0.01) by the high-fat diet after 8 weeks. The mRNA levels of ACC gradually increased over time and CPT-1 decreased over time, in both the liver and skeletal muscle in rats fed the high-fat diet.

CONCLUSIONSLipid accumulation in the liver occurs earlier than lipid accumulation in the skeletal muscle. Fatty liver may be one of the early markers of whole body IR. Changes in the gene expression levels of ACC and CPT-1 may have important roles in the process of IR development.

Acetyl-CoA Carboxylase ; genetics ; Animals ; Blood Glucose ; analysis ; Carnitine O-Palmitoyltransferase ; genetics ; Fatty Acids, Nonesterified ; blood ; Fatty Liver ; etiology ; Insulin Resistance ; Lipid Metabolism ; Liver ; metabolism ; Male ; Muscle, Skeletal ; metabolism ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Triglycerides ; metabolism

Objective: To analyze the drug resistance and genomic characteristics of Salmonella enterica serovar London isolated from clinical and food sources in Hangzhou City from 2017 to 2021. Methods: A total of 91 Salmonella enterica serovar London strains isolated from Hangzhou City from 2017 to 2021 were analyzed for drug susceptibility, pulsed field gel electrophoresis (PFGE) typing and whole genome sequencing. Multilocus sequence typing (MLST), core genome multilocus sequence typing (cgMLST) and detection of drug resistance genes were performed by using the sequencing data. Phylogenetic analysis was conducted to compare the 91 genomes from Hangzhou City with 347 genomes from public databases. Results: No significant difference in the drug resistance rate was observed between clinical strains and food strains to 18 drugs in Hangzhou City(all P>0.05), and the multidrug resistance (MDR) rate was 75.8% (69/91). Most strains were resistant to 7 drug classes simultaneously. One strain was resistant to Polymyxin E as well as positive for mcr-1.1, and 50.5% (46/91) of the strains were resistant to Azithromycin and were positive for mph(A). All 91 Salmonella enterica serovar London strains were ST155, which were subdivided into 44 molecular types by PFGE and 82 types by cgMLST. Phylogenetic analysis showed that most strains from Hangzhou City (83/91) were clustered together, and a small number of human isolates from Europe, North America and pork isolates from Hubei and Shenzhen were mixed in the cluster. Other strains from Hangzhou City (8/91) were closely related to strains from Europe, America and Southeast Asia. Strains isolated from pork were the most closely related to clinical strains. Conclusion: The epidemic of Salmonella enterica serovar London in Hangzhou City is mainly caused by the spread of ST155 strains, which is mainly transmitted locally. At the same time, cross-region transmission to Europe, North America, Southeast Asia, and other provinces and cities in China may also occur. There is no significant difference in the drug resistance rate between clinical strains and food strains, and a high level of MDR is found in the strains. Clinical infection of Salmonella enterica serovar London may be closely related to pork consumption in Hangzhou City.
Humans ; Salmonella enterica/genetics* ; Serogroup ; Anti-Bacterial Agents/pharmacology* ; Multilocus Sequence Typing ; Cities ; London ; Clonidine ; Phylogeny ; Genomics ; Drug Resistance ; Electrophoresis, Gel, Pulsed-Field ; Microbial Sensitivity Tests