PATHOPHY SIOLOGICAL MECHANISMS OF CONNECTIVE TISSUE REMODELI NG AND PROTEIN METABOLI SM IN ANIMALS SUBJECTED TO GAMMA IRRADI ATION

Abstract

Objective. The work investigated the pathophysiological mechanisms of connective tissue remodelling and protein metabolism in animals after a single total γ-irradiation at doses of 1.0 and 4.0 Gy. It was established that irradiation causes the expressed metabolic changes in the collagen and hyaluronic subsystems of the extracellular matrix, as well as in general protein metabolism. Activation of collagenolysis, an increase in the content of free oxyproline, the accumulation of hyaluronic acid and an increase in the ratio of hyaluronate synthase/hyaluronidase synthase were detected, which indicates the predominance of hyaluronate synthesis over its degradation. In parallel, a decrease in the level of bound oxyproline, serum protein, increased proteolysis and nitrogen excretion was observed, which reflects the development of negative nitrogen balance and protein-energy depletion. The detected changes indicate the transition of the organism to a catabolic type of metabolic response with destabilization of the structural and functional organization of connective tissue. The integral markers of protein pool disintegration were proposed to include an increase in the level of free oxyproline, hyaluronic acid, a shift in the ratio of hyaluronate synthase/hyaluronidase synthase, and increased nitrogen excretion. The results obtained deepen the understanding of the early metabolic links of radiation-induced connective tissue remodelling and can be used to identify early markers of post-radiation changes.