The persistence of blood-flow oscillations in the rat kidney

Abstract

The nonlinear dynamics of renal blood-flow oscillations in rats were studied in baseline conditions and a perturbed state. An intramuscular injection of aspirin in 0.9% saline (0.5 mg per 100 g body weight) served as the perturbation factor. Capillary blood flow in the right kidney was measured by laser Doppler flowmetry. The persistence of the time series was estimated by the Hurst method. The time series were shown to persist in the baseline conditions (Hurst index H = 0.817 ± 0.041). The statistical parameters of the perturbed state significantly differed from those that were observed at the baseline. However, the perturbed series remained persistent. The Hurst index for the series was H = 0.677 ± 0.057. The decrease in the index relative to the baseline was insignificant.