Inhibitory effect of 6-aminonicotinamide on the renal transport of para-aminohippurate in the rat.
In this study, we investigated the effect of 6-aminonicotinamide (6-AN), a typical potent inhibitor of the pentose phosphate pathway, on the renal transport of para-aminohippurate (PAH) in the rat. The contents of adenosine-triphosphate (ATP) and 6-phosphogluconate (6-PG) in the kidney were measured at intervals of 2 hours after the administration of 6-AN (75 mg/kg body weight, i.p.). It was found that the 6-PG content in the kidney rapidly increased and reached a plateau at the fourth hour after the administration, with this level being maintained up to the eighth hour. In contrast, the ATP content was found to remain normal up to the sixth hour, after which it significantly decreased as time elapsed. Furthermore, additional experiments were carried out by loading the rat with a high concentration of PAH solution at 6 hours after the administration of 6-AN. The renal tubular secretion maximum for PAH was significantly depressed in the 6-AN group in comparison to the control. These results suggest that this depression in renal PAH secretion capacity was partially due to the inhibition of the pentose phosphate pathway in the kidney, but not due to the change of renal ATP level.
D015120:6-Aminonicotinamide / Q000494:pharmacology*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000618:Aminohippuric Acids / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D005919:Glomerular Filtration Rate; D005942:Gluconates / Q000378:metabolism; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D007684:Kidney Tubules / Q000378:metabolism; D008297:Male; D009536:Niacinamide / Q000031:analogs & derivatives*; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000652:urine; D013997:Time Factors; D010130:p-Aminohippuric Acid / Q000378:metabolism* / Q000652:urine
D000618:Aminohippuric Acids; D005942:Gluconates; D009536:Niacinamide; D015120:6-Aminonicotinamide; D000255:Adenosine Triphosphate; D012964:Sodium; C008884:6-phosphogluconic acid; D010130:p-Aminohippuric Acid