Ultra low temperature refrigerator

High temperature autoclaves(TOMY SS-325, Tokyo, Japan); Ultra Clean Bench(Airtech SW-CJ-1F, Zhejiang, China); Ultra-low temperature refrigerators(Thermo, Waltham, MA, USA); Constant Temperature Oscillating Incubator(Multitron Standard, Lausanne, Switzerland); Lighted incubators(ZQLY-180N, Shanghai, China); High-speed frozen centrifuge (Eppendorf 5145R, Hamburg, Germany); analytical balance (BS124S, Burkhardtsdorf, Germany); water purifier (Direct-Q3, Bay City, MI, USA); pH meter (PHS-3C, Nanjing, China); PCR instrument (Bio-Rad C1000, Hercules, CA, USA); electrophoresis instrument (Bio-Rad Powerpac 300, Hercules, CA, USA); gel imager (Bio-Rad ChemiDoc MP, Hercules, CA, USA); nucleic acid protein analyser (Beckman DU800, Missouri City, TX, USA); Zeiss stereo microscope (Car Zeiss Discovery.v20, Göttingen, Germany); qRT-PCR instrument (Bio-Rad connect, Hercules, CA, USA); rotary evaporator (Buchi. V-850, Allschwil, Switzerland))
The reagents used in this study were purchased from the Sichuan Ruijinte Technology company.

Blood samples were collected via abdominal aorta puncture using separation gel coagulation promoting tubes. Separation of serum was completed within half an hour after blood collection using low temperature high speed centrifuge (2-16PK, Sigma, Germany), at 4°C, 3000 g for 15 min. Serum samples were preserved into 1.5-ml cryotubes stored at −80°C in ultra-low temperature refrigerator (Thermo Scientific, USA) until analysis of each indicator within a short period of time. Serum concentrations of Ang II, cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP), C-reactive protein (CRP), brain natriuretic peptide (BNP), serum creatinine (Scr), and blood urea nitrogen (BUN) in plasma were determined by radioimmunoassay using a RIA kit (Beijing Kangyuan Ruide Biotechnology Co., Ltd., Beijing, China) following the manufacturer’s instructions.