Abstract
The renal tubular secretion of N'-methylnivotinamide (NMN) by chickens was confirmed by unilateral infusion of NMN into the renal portal system and calculations of apparent tubular extraction fractions.
When NMN was infused systemically, into the wing vein, unilateral administration of 40 to 80 µg/minute of ouahain into the renal portal circulation resulted in an ipsilateral decrease in excretion of NMN and p-amino-hippuric acid (PAH) accompanied by increased excretion of Na+ and Cl-. Since depression of NMN was more pronounced than that of PAH, and inulin excretion was virtually unchanged, it was concluded that ouabain reduced tubular secretion of NMN.
Potassium reversed inhibitory effects of ouabain on NMN and Na+ transport.
The data strongly suggest that the renal tubular secretion of NMN (and presumably of other bases) is dependent upon the energy of adenosine triphosphate.
Footnotes
- Accepted October 21, 1964.
- The Williams & Wilkins Comapny
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