[Changes in blood pressure and erythrocyte sodium transport in subjects with normal blood pressure after dietary sodium loading].

The authors investigated in 20 healthy normotonics changes of the blood pressure and sodium transport in red cells after two dietary regimes: I. normal diet, II. normal diet + 5 g salt/day for a period of 7 days. After the salt load the following changes were observed: 1. a rise of the pressure and body weight 2. an increase of the mean blood pressure (MBP) by more than 7% in 11 subjects, described as "salt sensitive" (SS), the remaining 9 were not sensitive to salt (NSS); 3. a significant activation of ouabain sensitive transport (Na pump) in NSS. The authors did not observe a reduced activity of the Na pump found in volume expansion in essential hypertonics. On the other hand, after the salt load in normotonics an adaptive increase of the Na pump activation occurred which, however, was not sufficient in VSS normotonics. The authors assume that an inadequate response of the Na pump to a salt load in SS may be due to structural changes of the pump or its inadequate functional reserve which may be genetically conditioned and may lead secondarily to an increased salt sensitivity.