Changing trend and significance of serum IL-2 and IL-4 levels in rats with nephrotic syndrome

Objective: To investigate the relation between nephrotic syndrome (NS) and expression of interleukin-2 (IL-2) and interleukin-4 (IL-4) in serum of a NS rat model. Methods: A total of 40 healthy male Wistar rats were modeled and among these, 30 were randomly selected as the observation group according to a random number table. The NS model was established by one-time jugular vein injection of puromycin aminonucleoside. The remaining 10 rats underwent sham operation and served as the control group. After the model was established, peripheral blood was collected from all rats in both groups via the orbital venous plexus on day 1, day 7, and day 14. Serum levels of IL-2 and IL-4 levels were determined by enzyme-linked immunosorbent assay, and serum albumin and renal function index were measured by automatic biochemical analyzer. Prior to sacrificing the animals, urine was collected for 24 hours, and the biuret method was employed to determine the 24-hour urinary protein excretion rate. Results: In the observation group, typical NS symptoms, including proteinuria and edema, were observed 14 days after surgery. In 27 rats, the NS model was successfully established, and 3 rats died. The success rate was 90%. In the control group, 1 rat died 14 days after sham surgery, and the surgical success rate was 90%. The serum levels of IL-4 and creatinine levels on day 1, day 7, and day 14 of the observation group were significantly higher compared to those of the control group (all P<0.001). The 24-hour urinary protein excretion rates on day 7 and day 14 of the observation group were significantly higher than those of the control group (both P<0.001). Moreover, the levels of IL-2 and serum albumin of the observation group were lower than those of the control group (both P<0.001). In addition, on day 1 and day 7, the levels of blood urea nitrogen in the observation group were significantly higher than those in the control group (both P<0.05). Conclusion: The IL-2 level in the serum of NS rats decreased, whereas the IL-4 level increased, which might be related to the occurrence and development of NS.