Zdf fa fa rats

All animal work was performed according to the guidelines of the Institutional Animal Care and local veterinary office and ethics committee of Dalian Medical University (Permit Number: SYXK (Liao) 2008-0002). 5-week-old male ZDF (fa/fa) rats (n = 3) and their age-matched normal lean littermate controls (n = 3) were purchased from Vital River Laboratories (VRL) (Beijing, China) and housed in the specific pathogen-free (SPF) animal experiment center at Dalian Medical University. The rats were fed with high fat food and water (autoclaved before use) ad libitum and housed at 24 °C ± 2 °C with 65% ± 5% humidity on a 12 h light/dark cycle. Adaptive feeding lasted one week.

Male Zucker diabetic fatty (ZDF, fa/fa) rats and lean control Lean Zucker (LZ, fa/+) rats, all at 5 weeks old, were purchased from Vital River Laboratories (VRL) (Beijing, China). After arrival, the rats were acclimatized for 3 days under a standard specific-pathogen-free (SPF) environment (23°C, 12 h/12 h light/dark, 65% humidity, and ad libitum access to food and water) prior to experiment. The animal experiment protocol was designed to minimize the pain or discomfort of animals and has been approved by the Animal Ethics Committee of Nanjing University of Chinese Medicine (permit number: 201901A009).

Six-week-old male ZDF (fa/fa) rats and their Zucker lean (ZL, fa/+) littermates of the same age were both purchased from Vital River Laboratories (Beijing, China). During the experiment, the rats were placed in the specific, pathogen-free animal experiment center in Nanjing University of Chinese Medicine, and exposed to relative humidity (65% ± 5%), controlled temperature (24°C ± 2°C) and artificial light (12 h light/dark cycle) conditions. They had access to water (autoclaved before use) ad libitum with a standard diet for ZL rats and Purina 5008 chow for ZDF rats. Food and water intake and body weights were measured daily.
After 1 week of adaptive feeding, ZDF rats were randomized into two groups: chronic psychological stress T2DM rats (model group, n = 6) and psychological stress combined with ZBPYR administration rats (ZBPYR group, n = 6). They were all subjected to 6 weeks of stressful stimulation, which included restriction, rotation, and congestion. The stress procedures were performed as previously described in detail (Bi et al., 2020 (link)). Additionally, ZL rats were used as a control group (n = 6). All animal work was approved by the Animal Ethics Committee of Nanjing University of Chinese Medicine (Approval No. ACU170606) and performed according to the National Institutes of Health Guide for the Care and Use of Laboratory Animals.