[Animal modeling] - Establishment and evaluation of rheumatoid arthritis combined with hypertension disease model

  Objective: To establish a rat model of rheumatoid arthritis combined with hypertension, and to evaluate the characteristics of this model.

  Methods: The hypertensive model was established by constricting the left renal artery of rats with 0.25 mm silver clip, and the AHD model was established by injecting 0.1 mL complete Freund's adjuvant into the left hind foot of rats. Non invasive blood pressure measurement and analysis system measures the tail artery pressure. The paw volume meter was used to measure the joint swelling of the non inflammatory side of rats, and analyze the arthritis index and the incidence of inflammation. The rats were killed on the 35th day, and the thoracic aorta, ankle joint and spleen tissues were collected for HE staining and pathological examination.

  Results: The joints of AHD model rats were obviously swollen, a large number of synovial cells proliferated, inflammatory cells infiltrated, pannus formed, the number of spleen germinal centers increased, a large number of lymphocytes infiltrated, white pulp diffuse hyperplasia, red pulp infiltration. Arthritis index, incidence of inflammation and pathological score of joint and spleen tissues were significantly higher than those of adjuvant arthritis (AA) rats; At the same time, the blood pressure of AHD model rats increased significantly, the thickness and cross-sectional area of the thoracic aorta increased significantly, and the diameter of the lumen decreased significantly. The blood pressure value and the degree of vascular injury in AHD model rats were significantly higher or worse than those in HT rats.

  Conclusion: AHD model of rats can be successfully established by intradermal injection of complete Freund's adjuvant into plantar region combined with surgical operation to narrow left renal artery.