IZMENENIYa KOSTNOY TKANI ChELOVEKAV KOSMIChESKOM POLETE: O VOZMOZhNYKh MEKhANIZMAKh OSTEOPENII

Abstract

Some results of possible participation of bone metabolism regulation different levels in the bone changes caused by microgravity are presented taking into account the body fluid redistribution which usually accompany the space flight. The primary starting changes associate with biomechanical factors and realize on the strictly bone level (osteocytic osteolysis, breach of «collagen-crystal» connection, slowing of osteoblastic histogenesis). There are calcium homeostasis distortion on the extrabone (tissue, organs) level: decrease of calcium intestinal absorption and renal reabsorption. Changes in the hierarchy of ion and fluid volume regulation systems may provoke the osteoclastic resorption, which intensify the bone loss.