Rat Strain Comparison in Controlled Environment

Seven-week-old WIS (6 female and 6 male) and WKY rats (6 female and 6 male) (Charles River Japan, Yokohama, Japan) were examined. Rats were housed 3 per cage with free access to a standard diet for laboratory rodents (MF, Oriental Yeast, Tokyo, Japan) and water. A 12 h light/dark cycle (lights on at 08:00, lights off at 20:00), a room temperature of 23 °C, and humidity of 60% were maintained throughout the study. The study was performed according to the guidelines for Animal Experiments in the Faculty of Agriculture and in the Graduate Course of Kyushu University (A28-184-1), and in accordance with Law No. 105 and Notification No. 6 of the government of Japan.