Inorganic and organic anion interrelations in the active transport system for organic acids in the proximal kidney tubules
Mozhaeva, M.G.; Bresler, V.M.
Tsitologiia 24(4): 488-491
1982
ISSN/ISBN: 0041-3771 PMID: 7090051 Document Number: 188084
A mechanism of inhibitory action of inorganic anions (SCN- and SO 2/4-) on the transport of an organic acid (fluorescein) into proximal tubules was investigated in slices of the rat's kidney outer cortex. The peritubular S14CN- is shown to be accumulated in the cortical tissue by means of simple diffusion, this accumulation not depending on the presence of fluorescein in the medium. The peritubular 35SO 2/4- is accumulated in the tissue against the gradient of its electrochemical potential. It is very likely that the peritubular sulphate penetrates via intercellular contacts into the tubular lumen to be then actively reabsorbed by the Na+-dependent transport system in the luminal membrane. The sulphate accumulation is not affected by fluorescein added to the medium. It is concluded that the inhibition of organic acid transport after replacement of Cl- in the medium by SCN- or SO 2/4- may not be considered as a competition for a common carrier between organic and inorganic anions.