ObjectiveTo establish a chronic kidney disease-associated aortic calcification model in SD rats using different nephrectomy surgical methods, and to compare and evaluate surgical duration and survival time to explore a more optimized modeling method.MethodsAccording to different surgical methods, the SD rats were divided into four groups: Group A: intraperitoneal resection of 2/3 of the left kidney followed by right total nephrectomy in the second stage; Group B: intraperitoneal resection of 2/3 of the left kidney and simultaneous right total nephrectomy; Group C: dorsal approach right total nephrectomy followed by resection of 2/3 of the left kidney in the second stage; Group D: dorsal approach resection of 2/3 of the left kidney followed by right total nephrectomy in the second stage. After comparing survival curves of SD rats undergoing intraperitoneal versus dorsal approaches, and staged versus single-stage nephrectomy, the optimal nephrectomy surgical method was determined. Then, twenty-four 8-week-old SPF-grade male SD rats were selected for nephrectomy combined with calcitriol-induced calcification. Experimental group (12 rats): the dorsal approach left 2/3 nephrectomy followed by right total nephrectomy, with intraperitoneal injection of 1 μg/kg calcitriol administered one week later to induce aortic calcification. Control group (12 rats): the intraperitoneal injection of 250 μL/kg physiological saline containing 1% DMSO one week after sham surgery. After intraperitoneal injection of drugs for 3 months, the survival status of rats in each group was observed. Under anesthesia, blood samples were collected from each group to measure serum phosphorus and calcium ion concentrations, as well as serum urea nitrogen and creatinine levels. After euthanizing the rats, a post-mortem examination was performed to observe the residual kidney morphology, and HE staining was used to observe the pathological changes in the coronal section of the kidney. Additionally, the entire aorta of each group was taken, and the degree of aortic calcification was observed by staining with Alizarin red S and von Kossa. Real-time fluorescence quantitative PCR was used to detect the gene expression of smooth muscle actin-associated protein alpha (Sm22), Runt-related transcription factor 2 (Runx2), and osteopontin (OPN) in rat aortic tissue to evaluate the effectiveness of the model.ResultsThe exploratory optimization experiment of different surgical procedures found that the survival rate of group D rats, which underwent 2/3 left kidney resection followed by right whole kidney resection via the dorsal approach, was the highest, indicating that this surgical procedure was the best method for establishing a chronic kidney disease model with renal dysfunction. The experimental group rats treated with this surgical procedure combined with high-dose calcitriol injection had significantly lower serum calcium ion concentration than those in the sham-operated control group (P<0.05), while serum phosphorus ion concentration, serum creatinine, and serum urea nitrogen levels were significantly higher than those of the control group (P<0.05). HE staining of the kidneys showed significant organic changes in the kidneys of the experimental group rats, with a significant decrease in glomerular count compared to that of the control group (P<0.05), indicating the successful establishment of a renal failure model. Alizarin red S staining showed significant pigment deposition in the aortic media of the experimental group rats, while von Kossa staining showed significant silver nitrate deposition in the aortic media of the experimental group rats, which was consistent with the manifestation of aortic calcification in renal failure. Real-time fluorescence quantitative PCR showed that the expression level of Sm22 in the aortic tissue of the experimental group rats decreased (P<0.05), while the expression levels of OPN and Runx2 increased (P<0.05), indicating a transition of aortic smooth muscle cells from smooth muscle phenotype to bone-like phenotype and successful induction of an aortic calcification model.ConclusionThe method of establishing an aortic calcification model of chronic kidney disease in SD rats by first removing two-thirds of the left kidney via the dorsal approach followed by right total nephrectomy, combined with high-dose calcitriol administration, shortens the surgical time, improves the success rate of modeling, and increases the animal survival rate.