Specific pathogen free male sprague dawley rats

Specific-pathogen-free male Sprague-Dawley rats (n = 40; 9 weeks old; 270 ± 10 g) were obtained from Beijing Vital River Laboratory Animal Technology Co. (Beijing, China). Upon arrival, rats were housed under constant environmental conditions (room temperature 23°C ± 2°C on a 12:12-h light/dark cycle at 60% ± 5% humidity) with free access to standard rodent chow and filtered water. The animals were allowed to acclimate for 1 week prior to use in experiments. Experimental procedures were in accordance with the Ethical Principles of Animal Research and were approved by the National Research Institute for Family Planning Ethics Committee for Animal Research.

Specific pathogen-free male Sprague-Dawley rats (aged 6 weeks old and weighing 250 ± 20 g) were supplied by Beijing Vital River Laboratory Animal Technology Co. Ltd. (Beijing, China; license no. SCXK(Jing)2016-0006). All rats were bred and housed in the SPF animal facility at the Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College (Tianjin, China; license no. SYXK (Jin) 2019-0002) under controlled conditions in a 12-hour light/dark cycle with a ambient temperature of 20-25°C and a humidity at 40-70% for at least 3 days before preconditioning. Rats were allowed free access to a standard rodent diet and clean water. All procedures were approved by the Ethics Committee of Tianjin University of Traditional Chinese Medicine (TCM-LAEC2019018).