Conclusion
This study showed the effects of 1,25(OH)2D3 on the expression and function of rOCTN1 by investigating the interaction between 1,25(OH)2D3 and ergothioneine. Dose adjustment and possible changes in bioavailability should be considered before the co-administration of vitamin D or its active forms and OCTN1 substrates.
Methods
Rats pretreated with 1,25(OH)2D3 (2.56 nmol/kg/day) for four days were administered ergothioneine (2 mg/kg) intravenously. The expression levels of rat OCTN1 (rOCTN1) in organs were determined using real-time quantitative polymerase chain reaction. Ergothioneine levels in plasma, urine, and organs (with and without intravenous injection of exogenous ergothioneine) were determined using liquid chromatography-tandem mass spectrometry.
Purpose
This study aimed to investigate the effects of 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) on the expression levels of organic cation/carnitine transporter 1 (OCTN1) as well as the pharmacokinetics and biodistribution of ergothioneine, an OCTN1 substrate, in rats.
Results
1,25(OH)2D3 pretreatment resulted in a significant decrease in rOCTN1 mRNA expression levels in the kidney and brain, a significant increase in basal plasma levels of ergothioneine (from 48 h), and a significant decrease in the tissue-plasma partition coefficient (Kp) in all tissues (except the heart and lungs) and the basal urine levels of ergothioneine. After intravenous administration, the pharmacokinetic profiles of ergothioneine were consistent with the basal levels of endogenous ergothioneine, with an increase in AUC∞ by 85%, a significant decrease in total clearance by 49%, and a decrease in Vss by 32% in 1,25(OH)2D3-treated rats. The Kp value and urinary recovery of ergothioneine also decreased in the 1,25(OH)2D3-treated group.
Supplementary Information
The online version contains supplementary material available at 10.1007/s40005-022-00563-1.