Biocompatibility of Different Nicotinamide Riboside Doses Administered Intravenously to Rats

Nicotinamide riboside (NR) a NAD+ precursor. There is ample evidence in the literature for beneficial effects of its peroral administration in cardiovascular, neurodegenerative, renal, hepatic, and some other diseases. Previously, we have advanced a hypothesis that intravenous NR administration exerts a cardioprotective effect during doxorubicin anticancer chemotherapy. The present study was aimed to assess the biocompatibility of various NR doses during repeated intravenous drug administration to Wistar rats. The doses tested were the following: 150, 300, 450, and 600 mg/kg matching respective cumulative doses of 900, 1800, 2700, and 3600 mg/kg. Under this administration regimen, NR biocompatibility was demonstrated for the doses of 150, 300, and 450 mg/kg. Even at 450 mg/kg, repeated intravenous NR administration revealed no adverse effects on the cardiac parasympathetic ganglia of the autonomic nervous system. However, the dose of 600 mg/kg led to a number adverse side effects, including reduced cardiovascular efficiency, morphological and functional alterations in the myocardium, liver and kidneys, as well as a higher death rate and decreased exercise tolerance in rats.