[Effect of modeled microgravity on the secretory activity of cultivated human endothelium cells]

Endothelial cells monolayers are capable to respond to microenvironmental changes immediately by synthesis of vasoactive substances, chemokines, and expression of adhesion molecules. A variety of microgravity models were used to demonstrate the high mechanical and gravity sensitivity of the endothelium. The work was aimed at studying the effects of modeled microgravity on soluble cytokines synthesis by normal and TNF-activated human umbilical vein endotheliocytes. It was found that intact endothelial cells may differ in the ability to secrete IL-6 and IL-8 and that proinflammatory activation increases secretion of these interleukins. Manifestation of this effect is inversely proportional to basal cytokines secretion. Microgravity generated in the Random Positioning Machine does not affect the paracrine effects of proinflammatory induction. This suggests that microgravity is not a proinflammatory stimulant for endothelial cells; at least, it does not increase cytokines secretion or impede the development of inflammatory reaction.