[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.

[Morphological changes in gastric wall of mongolian gerbils following the 12-day orbital flight aboard Foton-M3].

Gastric wall of Meriones unguiculatus is distinguished by species-specific properties arising from the peculiar proportion of interstitium, muscle and epithelial tissues. Exposure to the factors of the 12-d Foton-M3 flight led to microfocal lesions of the mucous coat, dystrophic developments in the acid glands, dissociation of the mucous barrier function and deterioration of its biosynthetic function. Modifications of the tinctorial properties of the interstitium reticulum in every stomach layer progressed concurrently with reductions in prismatic epithelium height, as well as in mucous and muscular layer thickness. It is assumed that existence in the low gravity aboard the Biosat stimulated involutory processes in the gastric wall. Animals of the ground synchronous control conducted in the flight equipment mockup (Kontur-L) exhibited though similar yet less pronounced changes.

[Rna content of gerbil hepatocytes after the flight aboard space platform Foton-M3].

The paper compares and contrasts the results of measuring the hepatocyte cytoplasm area and RNA content in 35 gerbils in three series of experiments, i.e. the vivarium control, modeled space flight (synchronous control) and exposure to the factors of 12-d Foton-M3 orbital flight. Central, intermediate and peripheral zones of hepatic lobes were subjected to histological and histochemical analyses to measure the hepatocyte cytoplasm area; the RNA content was determined from the level of cytoplasm basophilia after azure staining. Cytometric and cytophotometric investigations were performed using image analyzer Video-7-Test-Morpho. In the vivarium animals, hepatocytes with the largest cytoplasm localized predominantly in the intermediate and central zones of the lobes. Judging from the results of microdensitometry, the RNA content was particularly high in binucleate hepatocytes of the intermediate zone. In the synchronous control, hepatocytes tended to grow in size, in the peripheral zone specifically, whereas RNA content was largely equal no matter hepatocyte topography. After space flight, cytoplasm enlargement transcended this process in the vivarium animals. The cytoplasm RNA content along the entire liver parenchyma made a significant decrease equally as compared with the vivarium and synchronous control animals.