The initial aim was to determine if the same responses occur in both animal models and to test the hypothesis that regulation of specific secretory protein expression is altered by space flight. The overall objective is to design biochemical tests to measure physiologic responses using biomarkers in saliva as indices. The ease of collecting saliva instead of blood and urine during space flight will make it possible to measure hormone changes experienced by Astronauts and Cosmonauts in microgravity.
Protein expression is considerably altered during space flight and demonstrated by electrophoresis, Western Blotting and immunocytochemistry. Significant changes were seen in the major salivary secretory proteins. In the parotid gland, PKA RII (Fig. 1), amylase and PRP showed a decrease, PSP was unchanged, and DCPP showed an increase in the flight animals compared to controls. A cellular enzyme (PDE) was decreased in flight animals. In the submandibular gland, NGF was significantly increased, whereas EGF was decreased, although not significantly (p=0.08). In the sublingual gland, mucin (MUC19) and PSP were significantly increased, whereas PKA RII and DCPP were unchanged. These results indicate that the responses to microgravity are specific to the gland, cell and protein. Proteins from heart muscle showed variability in the banding patterns of individual animals as well as differences between flight and controls. The ultrastructure of salivary glands is not significantly altered during space flight. Preliminary findings from STS-133 show similar results.
No data submitted. Summarized and analyzed data may be available through publications.