Diabetic animal models

Ten-week-old female db/db mice and C57BL/6 mice were provided by the Animal Laboratory Center of Nanjing university. The genetically diabetic mouse (db/db) has a mutation on the chromosome 4 that inhibits the expression of leptin receptor. The syndrome of type 2 diabetes mellitus in db/db mice is similar to adult humans and is characterized by hyperinsulinemia, obesity and progressive hyperglycemia. The mice were maintained on a standard diet and water ad libitum. The experiments conformed to standard environmental conditions for temperature (20–22 °C) and humidity (50–60 %). Half of the db/db mice were treated with NaHS (100 µmol/Kg) for 8 weeks. The animal experimental protocols complied with the ‘Guide for the Care and Use of Laboratory Animals’ published by the United States National Institutes of Health. The study was approved by the Institutional Animal Research Committee of Harbin Medical University (Harbin, People’s Republic of China).