The age-dependent changes in baroreflex control of heart rate were studied in inbred Dahl rats. At the age of 8 weeks the baroreflex slope was significantly greater in salt-resistant (R/Jr) than in salt-sensitive (S/Jr) rats fed a low- salt diet. The reverse was true in 16-week-old animals. High salt intake (8 % NaCI diet for 4 weeks) suppressed baroreflex efficiency in both age groups of S/Jr animals whereas no effects occurred in R/Jr rats. Baroreflex slope was, however, significantly lower in young S/Jr rats with a severe form of salt hypertension than in adult salt-loaded S/Jr rats in which only a moderate blood pressure elevation was observed.
The Vasotrac monitor provides non-invasive near-continuous blood pressure monitoring and is designed to be an alternative to direct intra-arterial blood pressure (BP) measurement. As compared to radial artery invasive BP and upper arm noninvasive BP, Vasotrac readings have been found to have a good agreement with them. However, discrepancies have been reported when rapid changes in BP exist. In the present study we compared BP measured by the Vasotrac monitor on the radial artery with that recorded on the finger arteries by the differential oscillometric device allowing measurement on the beat-to-beat basis. Comparisons were performed on the mean arterial pressure (MAP) level. Special attention was paid to the signal conditioning before comparison of pressures of different temporal resolution. Altogether 383 paired MAP measurements were made in 14 healthy subjects. Based on all 383 paired measurements, the MAP values measured at the radial artery at rest were 4.8±6.0 mm Hg higher than those measured on fingers. The observed difference between the Vasotrac and differential oscillometric device can be explained by different measurement sites. This result is consistent with previous investigations, and the Vasotrac monitor can be considered to adequately track relatively rapid MAP changes on the radial artery. Attention should be paid to a proper signal conditioning before comparison of results obtained by different devices., K. Jagomägi ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy