The Effects of Spaceflight on Mucin Production in the Mouse Uterus

The effects of microgravity on biological tissues are relatively unexplored, especially in regard to the mammalian female reproductive system. To begin to address this issue, the uterine tissue of female mice flown on NASA shuttle mission STS-118 was studied. Three sets of female mice, each consisting of 12 animals, were utilized in this study: flight animals, ground control animals, and baseline animals. The flight animals were housed in the Animal Enclosure Module (AEM) of the Commercial Biomedical Testing Module-2 (CBMT-2), which was a part of the payload of the shuttle’s mid-deck locker. Ground control animals were housed in ground-based AEMs, which were kept in a room specifically designed to mimic the environmental conditions of the flight units with regard to temperature, humidity, and light/dark cycles on a 48 hour delay. Baseline animals were housed in standard rodent cages at ambient temperature and humidity and a 12/12 light/dark cycle. The uterine tissue was stained using an Alcian Blue Periodic Acid Schiff staining procedure and the apical mucin layer thickness was subsequently analyzed. Analysis of the mucin layer in the uterus revealed that the thickness of the mucin layer in the flight tissue was significantly thicker that the mucin layers of the ground control and baseline tissue.