Sprague dawley rats

Twenty-four male Sprague-Dawley rats (RRID: MGI: 5651135) at 6–8 weeks, weighing approximately 160–180 g, were purchased from Beijing SPF Biotechnology Co., Ltd. with License No. SCXK (Beijing) 2019-0008. Rats were maintained in a room on a 12-h light/dark cycle with 50%–60% humidity and a temperature of 20°C–24°C. Free access to both water and food was provided. Animal experiments were approved by the Ethics Committee for Animal Experiments of Chengdu University of Traditional Chinese Medicine (No. 2021-66) and performed in accordance with the National Institutes of Health guidelines. The rats were randomly divided into three groups (n = 8 per group): the control (C) group—an equal amount of olive oil solution and saline during modeling and gavage; the model (M) group—CCl₄ olive oil solution (40%, 3 mL/kg, s.c.) twice a week for 8 weeks, then once per week for 6 weeks and an equal amount of saline daily for the same 6 weeks; the QJ group—CCl₄ olive oil solution twice a week for 8 weeks, then once per week for 6 weeks and QJ daily for the same 6 weeks. Rats were anesthetized with 3% sodium pentobarbital (50 mg/kg, i.p.). The contents of the large intestine were collected under sterile conditions in a clean bench, and then samples of abdominal aortic blood, liver, and ileum were collected. Rats were finally euthanized by an overdose of sodium pentobarbital.

Pregnant specific pathogen free (SPF) Sprague Dawley rats were obtained from SPF Biotechnology Co., Ltd. (Beijing, China), and arrived in the lab on day 15 of their pregnancies. Rats were housed in standard polypropylene shoebox cages (42 × 20.5 × 20 cm) on hardwood chip bedding in a designated room with controlled lighting (12:12 h light–dark cycle) at 22°C to 24°C and allowed free access to water and a standard diet. Pregnant rats were checked daily for litter, and the day of birth was defined as the postnatal day (PND) 0 for the litter. After delivery, the dams and litters were housed together until weaning (PND22). After weaning on PND22, male and female rats were separated, and three animals were kept in a single standard cage. Only male rats were included in this study to avoid the effects of hormones (n = 7 for each group). The experimental animal protocol was approved by the Ethics Committee of Minzu University of China (ECMUC2019005AO). The study was carried out in a Good Laboratory Practice (GLP) accredited laboratory.

Sprague‐Dawley rats (20 weeks old, weighing 200‐230 g) were obtained from SPF Biotechnology Co., Ltd (Beijing, China). The Institutional Animal Welfare Committee of the Peking Union Medical College Hospital and the Laboratory Animal Center of Army General Hospital approved this study (protocol no. SYXK 2014‐0037), and all experimental procedures were performed in accordance with the national guideline for animal care. All rats were housed with five rats per cage at room temperature (21‐23°C) with 60%‐70% humidity and a 12‐hour light/dark cycle. Rats had free access to standard water and rat chow.
The rat model of VAD‐induced CS was created as described previously.7 Briefly, female rats (n = 96) were randomly assigned to either the VAD group (n = 48), which received a modified AIN‐93G diet without any vitamin A source (Research Diets, New Brunswick, NJ) or the control group (CON, n = 48), which received an AIN‐93G diet with adequate vitamin A (4 retinol equivalents (RE)/g diet). Vitamin A deficiency was detected and confirmed in the VAD group after the rats were fed the VAD diet for more than 2 weeks as described previously.7, 20 The female rats were then mated with normal male rats at 6‐10 pm and continuously received the same diet during gestation.21

Sixty-two Sprague–Dawley rats (200 ± 20 g) and 20 C57BL/6 mice were obtained from SPF biotechnology co., LTD. (Beijing, China). Animals were maintained in specific pathogen-free facilities and housed in filter-top cages with free access to food and water under a 12-h light: 12-h dark cycle in plastic cages at 25°C ± 2°C with a relative humidity of 50% ± 10%. The animal experiments were approved by the Experimental Animal Care and Ethics Committee of the First Affiliated Hospital, Henan University of Chinese Medicine.

At postnatal day (PND) 3, female Sprague-Dawley rats and their mothers were obtained from SPF Biotechnology Co., Ltd. (Beijing, license no: SYXK (Beijing) 2016–0038). The rats were housed in the laboratory animal room and maintained at 24 ± 2°C, with 42 ± 5% humidity on a 12-h light/dark cycle (lights on from 07:30 to 19:30) in a specific-pathogen-free animal room. The animals were supplied food and water ad libitum and acclimated for three days before the start of the experiments. All animal experiments were performed in strict compliance with Chinese guidelines, including the standards for Laboratory Animals (GB14925–2001), and the Guideline on the Humane Treatment of Laboratory Animals (MOST 2006a). All animal procedures were approved by the Beijing Administration Office for Laboratory Animals.