Cytosolic calcium and hemorheological patterns during arterial hypertension

Hypertension can be considered as a progressive ischaemic syndrome interesting micro- and macrovasculature. In hypertensives it is possible to observe a link between an increase in peripheral resistance and blood viscosity, and a decrease in red blood cell (RBC) deformability. It is important to underline the link between the increase of blood viscosity, the decrease of RBC deformability and the cytosolic calcium level, which is related to the ischaemic syndrome in hypertension. The aim of this study was to evaluate the level of Ca++ and its possible correlation with hemorheological patterns during arterial hypertension. Two groups were studied: Group 1 consisted of 18 mild hypertensives (11 males and 7 pre-menopausal females, aged 39 +/- 3 years). This group was of medium risk according to WHO and ISH (1999) with no other pathologies apart from peripheral occlusive arterial disease II stage type A. Group 2 was made up of 14 healthy subjects (9 males and 5 females, aged 34 +/- 4 years). The intraerythrocytic cytosolic calcium was evaluated using a fluorescent marker FURA 2/AM (Calbiochem). The following hemorheological parameters were also assessed using the new Laser assisted Optical Rotational Red Cell Analyzer (LORCA) according to the Hardeman method (1994): RBC deformability-Elongation Index (EI), RBC aggregability- aggregation half time (t 1/2). The data obtained showed that compared to the control group the hypertensives had a significantly higher level of intraerythrocytic cytosolic calcium (p < 0.01), plus a significant decrease in EI and t 1/2 evaluated using LORCA. We also observed a significant correlation (p < 0.01) between an increase in Ca++ and a decrease in EI in the hypertensive patients. Moreover our study revealed a significant correlation between the increase in intraerythrocytic Ca++ and the t 1/2 decrease. The evaluation of the hemorheological patterns and cytosolic calcium could explain the impairment in peripheral perfusion and oxygenation in hypertensive patients and could provide a good model for a better evaluation and treatment of microvasculature perfusion in subjects with essential and complicated hypertension.