Methods
A swimming experiment was designed in rat to objectively observe exercise capacity. The Sprague-Dawley male rat were obtained from the Animal Center of Health Science University. Based on the findings of the G power 3.1 analysis, it was determined that a minimum of six rat per group would be necessary to achieve the desired experimental power. Consequently, the study was designed to include a total of 24 animals, following the appropriate ethical procedures by seeking approval from the animal experiments ethics committee.
The subjects were accommodated in a controlled environment with a 12-hour light and dark cycle, at a temperature of 25 °C, and a relative air humidity of 40%. They were provided with ad libitum access to water and feed, and were allowed unrestricted activity within a laboratory animal room for a minimum duration of one week. Then, 3-month-old rat were randomly divided into three groups. The Rota-Rod test was employed to measure the motor coordination and antifatigue ability of rat at the beginning of the study. The Rota-Rod test consists of a cylindrical rod with a diameter of 3 cm, which has been partitioned into five tracks each with a width of 6 cm. Additionally, the apparatus includes an infrared detector and a computer. The Rota-Rod test comprises a rotating rod with a diameter of 3 cm (this rod was divided into 5 tracks with a width of 6 cm), an infrared detector, and a computer. In the test, rat were positioned on the horizontally oriented, rotating rod. It was ensured that there were no differences between groups.
In the first group, 60 mg/kg/1ml dose of sacubitril/valsartan was administered every day by oral gavage. In the second group, 1,5mg/kg/1ml dose of dapagliflozin was administered every day by oral gavage. The third group was the control group. The researchers who administered the drug and the researchers who performed the swim test were different people. The researcher who performed the swim test was unaware of the groups’ information.
Initially, before the experiment, each group had swimming training in the water tank for three days. Each mouse was placed in a different water tank. The water tank was designed with a size of 40x40 cm and a height of 50 cm. The swimming tank was maintained at a temperature of 28ºC throughout the swimming process. The endurance of each mouse was assessed by measuring the swimming time from the start of the activity until exhaustion, which was determined by observing uncoordinated movements and the inability to resurface within a period of 7 seconds. The maximum swimming seconds of each mouse were recorded daily. In addition, echocardiography (ECHO) and heart rate measurements were performed in each mouse at the beginning of the experiment, on the 15th day and at the end of the experiment.