Evidence for enhanced Na transport in hypertension induced by DOCA in the rat

Uninephrectomized rats were treated with DOCA-saline for 3 weeks. Active Na transport activity was assessed in the rat tail artery in three separate ways. In the first method, Na-K exchange was expressed in terms of steady-state values in normal and ouabain-blocked arteries. In the second method, the relation of free cell Na to [Na]0 was measured after equilibration in media in which [Na]0 varied from about 25 to 140 mM. In the third method, the relation of cell K to [k]0 was measured with glass electrodes during the reestablishment of normality following prolonged K depletion. All methods yielded evidence of enhanced net active transport activity in the incubated artery (zero intraluminal pressure) in steady state.