Modeling of rheumatoid arthritis is accompanied by a change in the cortico-papillary ratio of hyaluronidase activity of the kidneys

Abstract

Background . Rheumatoid arthritis is a disease that is accompanied by impaired kidney function in most patients, which attracts the attention of researchers to this problem. Both in the joints and in the kidneys, hyaluronic acid plays an important role, the degree of polymerization of which depends on the functioning of these organs. The degradation of hyaluronic acid by hyaluronidases may be a factor involved in the development of the inflammatory process in rheumatoid arthritis as well as in the realization of osmoregulatory functions of the body. In this regard, the purpose of this work was to find out whether the development of this pathology can affect on the hyaluronidase activity in the kidneys. THE AIM: to clarify is in the experiment formation of inflammatory changes in the joints accompanied by a change in the cortico-papillary ratio of hyaluronidase activity in the kidneys. Materials and Methods . A model of rheumatoid arthritis was created in Wistar rats by a single administration of a complete Freund adjuvant. After 7 weeks after injection, the degree of pathological changes in the joints was assessed by radiographic method and the hyaluronidase activity in various kidney zones was determined using zymography. Results . It was revealed that in the cortex and papillary zone of the kidneys, hyaluronidase activity was characteristic of proteins with a molecular weight of 63 and 73 kDa. It has been shown that the development of the inflammatory process is accompanied by a change in the corticopapillary ratio of hyaluronidase activity in the kidneys. In the papillary zone, a decrease in hyaluronidase activity was observed, on average, by 1.6 times, while in the renal cortex, hyaluronidase activity increased by 1.5 times. Conclusion . Such a redistribution of hyaluronidase activity in the cortical and papillary zones of the kidneys in rheumatoid arthritis can lead to a decrease in the effectiveness of the mechanism of osmotic concentration of urine and impaired kidney function.