RENAL TUBULAR ELIMINATION OF N1-METHYLNICOTINAMIDE

Abstract

N1 -methylnicotinamide (NMN) is excreted by the combined processes of glomerular filtration and tubular secretion. The transport mechanism for the tubular secretion NMN is distinct, functionally, from that responsible for the secretion of p-amino-hippurate, penicillin, and phenol red by the tubules. Carinamide, which blocks the tubular secretion of p-aminohippurate and compounds eliminated by that same tubular mechanism, does not interfere with the tubular transport system for NMN se''cretion. The compounds secreted by the 2 cellular mechanisms are not mutually competitive, nor do they suppress the functional capacity of the opposite transport system, within the limits of these expts. NMN does not appear to be bound on plasma components. Nicotinamide, trigonelline and 1-methyl-3-carboxyl-amide-6-pyridone do not inhibit the renal elimination of N1-methylnicotinamide.