[Jejunum intersticium in mongolian gerbils after the flight on spacecraft Foton-M3]

Methods of light optical microscopy were used to explore histoarchitectonics, topography and tinctorial properties of the extracellular phase of fibers of jejunum wall intersticium in Mongolian gerbils following 12-day orbital flight aboard Foton-M3, ground-based simulation of the spaceflight factors in the KONTUR-L facility, and in the group of biological control Postflight destructive changes were found in reticulin fibers (type-III collagen) of villi stroma, intercrypt intersticium and submucosa. Local acidophilia and fiber homogenization formed in type I collagen present in the intestinal subserous layer, muscular layers endomysium and submucose against the background of progressing edema and arterial, venous plethora and lymphostasis. Elastic component of the intersticium was disarranged in the structures of internal elastic membrane of submucous vessels, fragmented and partly reduced. Simulation of the orbital factors, except for microgravity, in the KONTUR-L facility called forth similar, although less often and diffuse, changes in intersticium fibers. The results of examination of intestinal intersticium fibers in the vivarium control gerbils discovered expressed species characters that should be taken into account by investigators, especially when comparing with data obtained from other animal species.