Abstract
Background: Hypertension is a common disease and uncontrolled, long-term hypertension is associated with serious complication of vital organs such as brain, heart and kidneys. Although elevation of blood pressure (BP) is based on rise in peripheral vascular resistance, the role of vasoconstriction on the rheologic blood properties is unknown due in part to limited methodologies. Methods: Since spontaneous hypertensive rat (SHR) is a popular and excellent model of human hypertension, we investigated the role of erythrocyte deformability on the maintenance of high BP using 13-week-old SHR. BP was measured by tail sphygmomanometry. Erythrocyte filterability was rheologically considered as whole cell deformability, and was evaluated by gravity-based nickel mesh filtration technique. Results: We found that erythrocyte filterability was significantly (p<0.001) impaired in SHR (51.5 ± 11.5%) relative to that of 13-week-old Wistar rat (73.1 ± 8.3%). Hypertension was established in SHR whereas BP in Wistar rat remained constant in this stage (168/133 mmHg vs 108/84 mmHg in average). Conclusion: Erythrocyte filterability of SHR is still impaired in the stage of established hypertension. This is contradictory to the results of a previous study (Chabanel A, et al: Hypertension 10: 603, 1987) and this difference may stem from methodological quantitativity and reproducibility. [J Physiol Sci. 2008;58 Suppl:S187]
