Presenile (early ageing) changes in tissues of Kaschin-Beck disease and its pathogenetic significance.

The selenium level and activity of glutathione peroxidase in blood of children living in Kaschin-Beck disease (KBD) endemic areas were lower than that in nonendemic areas. KBD children were deficient in selenium, their lipid components, structure and function of the red cell membrane and cartilage tissue were abnormal. That is, the phospholipid (PL) content in the tissues of the patient was less than that of the controls in endemic and non-endemic areas. Especially as the phosphatidylcholine (PC) content decreased significantly, but sphingomyelin (SM) increased, the molar ratio of SM/PC and cholesterol (Ch)/PL increased. Increase of acanthocyte content was seen under the electron microscope and the fragility of erythrocytes was also increased. It indicated that there were membrane defects and membrane damage in KBD. At the same time, the sulfation extent of mucopolysaccharides in cartilage of patients was lower, and the collagen content was higher than that of controls. The presenile changes in lipid composition, structure and function of biomembranes and cartilage metabolism of KBD are very significant in studies on the aetiological pathogenesis of KBD and other ageing diseases.