Experiment K-7-20: Pituitary Oxytocin and Vasopressin Content of Rats Flown on Cosmos 2044

Pituitary levels of oxytocin (OT) and vasopressin (VP) were measured in rats exposed to 14 days of spaceflight (FLT) as well as in ground-based controls; one group synchronously maintained in flight-type cages with similar feeding schedules (SYN), one group in vivarium cages (VIV), and a group of tail suspended (SUS) animals. Flight rats had significantly less (p less than 0.05) pituitary OT and VP (4.48 +/- 0.31 and 7.48 +/- 0.53 mg hormone / mg protein, n = 5) than either the SYN (6.66 +/- 0..59 and 10.98 + 1.00, n = 5), VIV (6.14 +/- 0.40 and 10.98 +/- 0..81, n = 5) or SUS (5.73 +/- 0.24, n = 4) control groups, respectively. The reduced levels of pituitary OT and VP are similar to measurements made on rats from the previous 12.5 day Cosmos 1887 mission and appear to be a direct result of exposure to spaceflight.