Effect of antiorthostatic hypokinetic/hypodynamia on urinary endothelin-1 and N-acetyl-beta-D-glucosaminidase excretion in rats.

In an experimental model with rats in head-down suspension, plasma levels and urinary excretion of endothelin-1 (ET-1) and urinary excretion of N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30; NAG) were determined. Significant variations in time in the effective plasma ET-1 levels in the superior and inferior cava vessel blood of animals maintained for 6 days in hypogravity with respect to controls were observed. We not only found a transient increase in urinary NAG activity but also that the levels of U-ET-1 increased during head-down suspension. The simultaneous evaluation at urinary level of these two parameters could be an indication that there are different sites of renal parenchymal involvement or injury during antiorthostatic hypokinesis.