In our previous studies, we observed that rat kidney weight/body weight ratio was significantly elevated at 1 h post-45 degree head-down tilt (45HDT) -vs- prone controls (PC). This same model (N=6 for 45 HDT and N=4 for PC) was utilized to measure kidney clearance of diethylenetriamine pentaacetate (99mTc-DTPA, MW = 492 amu, physical half-life of 6.02 h). The 99mTc-DTPA counts were measured at minute intervals for a 10 min baseline (prone position) and for 1 h at either a 45 HDT or prone position. At the end of the 1 h experimental timeperiod, the kidneys were harvested, weighed, and underwent electron microscopic analysis. The 45HDT group showed changes in 99mTc-DTPA kidney clearance compared to their baseline values accompanied by ultrastructural changes in the kidney proximal tubules. We did not observe these changes in the PC group. We conclude that the kidney undergoes significant physiological changes immediately after 45HDT. These observations may have implications for designing effective counter-measures for astronauts due to the deleterious effects of microgravity.
|Original language||English (US)|
|State||Published - Mar 20 1998|
ASJC Scopus subject areas
- Molecular Biology