Publications by authors named "K Nunoya"

P-glycoprotein (P-gp) is an efflux transporter that plays an important role in the pharmacokinetics of its substrate, and P-gp activities can be altered by induction and inhibition effects of rifampicin. This study aimed to establish a physiologically based pharmacokinetic (PBPK) model of rifampicin to predict the P-gp-mediated drug-drug interactions (DDIs) and assess the DDI impact in the intestine, liver, and kidney. The induction and inhibition parameters of rifampicin for P-gp were estimated using two of seven DDI cases of rifampicin and digoxin and incorporated into our previously constructed PBPK model of rifampicin.

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Article Synopsis
  • In human plasma, the prodrug ONO-2160 is primarily hydrolyzed by alpha-1-acid glycoprotein (AGP), which includes two variants: F1*S and A at a 3:1 to 2:1 ratio.
  • A study showed that both AGP variants hydrolyze ONO-2160, but the F1*S variant has a significantly higher esterase-like activity, being about 30 times more effective than the A variant.
  • Inhibition studies revealed that compounds with higher affinity for the F1*S variant inhibit ONO-2160 hydrolysis more effectively, indicating that this variant is mainly responsible for the drug's hydrolysis at its ligand-binding site.
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Previously, we found that ONO-2160, an ester-type prodrug of levodopa (3-hydroxy-l-tyrosine), was mainly hydrolyzed in human plasma by α-acid glycoprotein (AGP) with a partial contribution of albumin. In this study, we investigated whether ONO-2160 was hydrolyzed in the plasma of preclinical species (dog, rabbit, rat, and mouse) and humans and whether AGP and albumin are involved in its hydrolysis. ONO-2160 was hydrolyzed to some extent in the plasma of all tested species with the order of magnitude mouse > human > rabbit > rat > dog.

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Brain microvascular endothelial cells (BMEC), together with astrocytes and pericytes, form the blood-brain barrier (BBB) that strictly restricts drug penetration into the brain. Therefore, in central nervous system drug development, the establishment of an human BBB model for use in studies estimating the human BBB permeability of drug candidates has long been awaited. The current study developed and characterized a human immortalized cell-based BBB triculture model, termed the "hiBBB" model.

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