THE BINDING OF ORGANIC BASES TO KIDNEY CORTEX SLICES

¹ Department of Pharmacology, School of Medicine, State University of New York at Buffalo, Buffalo, New York

The accumulation of a series of polymethylenebis(trimethylammonium) ions by slices of kidney cortex from rats, rabbits, chickens, cats and dogs has been compared with the accumulation of tetraethylammonium and N-methylnicotinamide. Great variation in ability to accumulate all bases was observed among different species of laboratory animals; no consistent pattern of activity correlated with structure was discernible. Renal slices from chickens accumulated all the bases studied except ethylenebis (trimethylammonium). The kidney slices from rabbits did not take up any bisquaternary ammonium ion and showed high slice/medium ratios only with tetraethylammonium. Any bisquaternary ammonium ion that was accumulated exhibited nonsaturable uptake kinetics; the slice/medium ratio increased in an almost linear fashion with time. The slice/medium ratio of monoquaternary ammonium ions reached a limiting value in one to three hours, at which time the rate of loss from tissue was about equal to the rate of uptake. The order of potency of mepiperphenidol, tetraethylammonium, N-methylnicotinamide, quinine, cyanine, hexamethonium and decamethonium as inhibitors of renal uptake of mono- and bisquaternary amines was, in general, similar. However, decamethonium was a more potent inhibitor of bisquaternary than of monoquaternary amine uptake. It is concluded that bisquaternary ammonium ions are transported into renal cells by a system involved in organic base transport, and that the rate of loss of bisquaternary ammonium ions from renal cells is low.