Red blood cell Na+ content is poorly related to essential hypertension and to membrane Na+ transport abnormalities

Hemorrheological indices, catecholamines, neuropeptide Y and serotonin in patients with essential hypertension

Hemorrheological and humoral abnormalities and excessive platelet activity can predict the development of cardiovascular complications in patients with essential hypertension. A study was conducted to assess the influence of gender on these factors and the interrelations between changes in hemorrheology and the sympatho-adrenal system in 54 patients (18 women, 36 men) with essential hypertension (aged 39.6 +/- 9.7 years) and 25 healthy volunteers (10 women, 15 men; aged 36.0 +/- 7.2 years). A decrease in erythrocyte deformability (p < 0.01) was found in the hypertensive men compared with the hypertensive women. Hematocrit (p < 0.01), blood viscosity at the shear rates of 0.3 s-1 (p < 0.01) and 6 s-1 (p < 0.01), plasma viscosity (p < 0.01), erythrocyte aggregation (p < 0.01), and neuropeptide Y (p < 0.02) concentrations were higher in the hypertensive men than in the hypertensive women. A positive correlation between blood fibrinogen and serotonin was found in the pooled hypertensive group and in the hypertensive men (p < 0.01) and between blood viscosity (shear rate 6 s-1) and neuropeptide Y in the pooled hypertensive group (p < 0.01). Neuropeptide Y correlated with filtration time of 1 mL blood in the hypertensive men (p < 0.05) and in the pooled normotensive group (p < 0.01) and with beta-thromboglobulin in the hypertensive women (p < 0.001). A positive correlation was also found in the hypertensive men between erythrocyte and platelet aggregation (p < 0.01) and between beta-thromboglobulin and adrenaline (p < 0.01). Hemorrheological and humoral abnormalities are more pronounced in men than in women with essential hypertension and may contribute to the increased incidence of cardiovascular events in men.

Sodium-lithium countertransport and family history of hypertension in childhood

We have studied the relationship between sodium-lithium countertransport, determined in childhood, and family history of hypertension. Countertransport was measured in healthy children and those with secondary hypertension. There was no significant difference in countertransport between these two groups. In the normal children (n = 52, median age 6.8 years), there was a positive relationship between body mass index and countertransport (rs = 0.34, p < 0.02). A positive relationship between family history of hypertension using a ranked scoring system, and countertransport, not related to age, body mass or blood pressure (n = 34, rs = 0.63, p < 0.001) was also found. There was no significant relationship between intracellular sodium concentration and countertransport. These data confirm that countertransport in normal children is related to body mass index and indicate that a genetic predisposition to primary hypertension marked by sodium-lithium countertransport is identifiable in childhood.