Histochemical alterations in the digestive tract of rats after 13 days of flight in the "Cosmos 1887" biosatellite.

In rats recovered after 13 days of cosmic flight a diminution of acid and neutral glycoproteins was observed in the gastric mucosa and proximal segments of the small intestine: the decrease was less evident in the sublingual glands and colon. Leucine aminopeptidase and acid phosphatase in the small intestine were intensified. No significant changes were observed in the other enzymes investigated. Acid phosphatase showed a more intense activity in the endocrine pancreas B cells. The alterations observed after 13 days of flight in the "Cosmos 1887" biosatellite are significant but less marked than after 18 days of flight, and more accentuated than after 5-7 days of flight.