Impaired erythrocyte filterability of spontaneously hypertensive rats: investigation by nickel filtration technique.

ABSTRACT

BACKGROUND: Deformability of erythrocytes plays a key role in the impairment of the microcirculation in hypertension. However, erythrocyte deformability in spontaneously hypertensive rats (SHR) during development of hypertension has not been fully investigated so far. METHODS AND RESULTS: Erythrocyte filterability (whole cell deformability) was investigated in relation to blood pressure measured by the tail-cuff method in SHR and age-matched Wistar-Kyoto rats (WKY), using a highly sensitive and reproducible nickel mesh filtration technique. Impaired erythrocyte filterability was marked (37.0+/-17.5%) in prehypertensive young SHR (7 weeks of age) and sustained (51.6+/-13.3%) in hypertensive mature SHR (18 weeks of age), when compared with that of age-matched WKY (62.1+/-7.2% in 7 weeks of age, P<0.005, and 71.1+/-3.9% in 18 weeks of age, P<0.005, respectively). This impairment in SHR could not be explained by the mean corpuscular volume or mean corpuscular hemoglobin concentration of erythrocytes, but the erythrocyte count was significantly (P<0.005) greater in SHR than in the age-matched WKY. CONCLUSIONS: Although the precise mechanisms remain to be elucidated, markedly impaired erythrocyte filterability in SHR is considered to contribute to the development and maintenance of genetic hypertension. (Circ J 2010; 74 129 - 136).