A method of continuous renal capillary microperfusions of the same area at different solute concentrations

The microperfusion pump described in this paper allows to perfuse the same peritubular capillary area on the renal surface with different test solutions. Solutions can be changed by means of a microcannula inside the pump which for this purpose can be moved near to the tip of the pipette. Concentration effect relations of various agents may thus be obtained on the single nephron level in vivo. This is illustrated on the example of the inhibitory effect of acetazolamide on proximal tubular reabsorption. Inhibition of this tubular function has been assessed by means of repeated determinations of split droplet half times.