Article Figures & Data
Figures
- Fig. 1.
Metabolic pathways of vildagliptin in humans. The major metabolic pathway of vildagliptin in humans is DPP-4–mediated hydrolysis at the cyano group to produce a carboxylic acid metabolite M20.7 (He et al., 2009a; Asakura et al., 2015). Vildagliptin is also metabolized to form amide bond hydrolysis (M15.3), glucuronidation (M20.2), and oxidation on the pyrrolidine moiety of vildagliptin (M20.9 and M21.6). Reported amount of vildagliptin and metabolites in urine and feces is indicated as percentage of dose (He et al., 2009a).
- Fig. 2.
Pharmacokinetics study of vildagliptin and M20.7. Pharmacokinetics of vildagliptin (A) and its main metabolite M20.7 (B) in control mice administered with vildagliptin (10 mg/kg, per os) (n = 4), mice coadministered with vildagliptin (10 mg/kg, per os) and sitagliptin (1000 mg/kg) (n = 3), and STZ-induced diabetic mice administered with vildagliptin (10 mg/kg, per os) (n = 3) are shown. Results are shown as means ± S.D. of the plasma concentrations of vildagliptin and M20.7.
- Fig. 3.
DPP-4 activities and vildagliptin cyano group-hydrolyzing activities in liver, kidney, small intestine, and plasma in control mice and STZ-induced diabetic mice. Tissues were collected 48 hours after administration of vildagliptin in the pharmacokinetics study, and then pooled samples of each tissue in control mice (n = 4) and STZ-induced diabetic mice (n = 3) were prepared. (A) DPP-4 activities in S9 fractions and plasma were measured using Gly-Pro-AMC as a substrate. Data represent the means ± S.D. of three independent experiments. **P < 0.01. (B) The DPP-4 protein expression levels were determined by Western blot analysis. Liver, kidney, small intestine S9 fractions, and plasma (100 µg protein) of control mice and STZ-induced diabetic mice were subjected to NuPAGE 4–12% Bis-Tris gel and probed with the anti–DPP-4 antibody. (C) The vildagliptin cyano group-hydrolyzing activities in S9 fractions were measured. The substrate concentration was 1 µM. Data represent the means ± S.D. of three independent experiments. **P < 0.01. ND, not detectable. (D) The estimated DPP-4 activities (nmol/min/tissue or plasma) in whole liver, kidney, small intestine tissues, and plasma are shown. Data represent the means ± S.D. **P < 0.01. (E) The estimated M20.7 formation rates (pmol/h/tissue) in whole liver, kidney, and small intestine tissues are shown. Data represent the means ± S.D. **P < 0.01. ND, not detectable.
- Fig. 4.
Correlation between hepatic DPP-4 activities and vildagliptin cyano group-hydrolyzing activities in individual mice. The relationships between hepatic DPP-4 activities and hepatic M20.7 formation rates (A) and the AUC0–8 hours values of M20.7 (B) in individual mice are shown. The correlation analysis was performed using the Spearman rank method. Data represent the means of triplicate determinations.
- Fig. 5.
The mRNA expression levels of Dpp-4 (A), Foxa2 (B), collagen, type I, α1 (C), Fabp4 (D), adiponectin (E), Hnf-1α (F), and Fabp1 (G) in liver, kidney, and small intestine of control mice and STZ-induced diabetic mice. Expression was normalized with the expression of cyclophilin, and the expression level in each tissue of control mice was defined as 1. Data represent the means ± S.D. of three independent experiments. *P < 0.05; **P < 0.01. ND, not detectable.
- Fig. 6.
Interindividual variability of hepatic DPP-4 activities and vildagliptin cyano group-hydrolyzing activities. (A) The hepatic DPP-4 activities in a panel of 23 individual HLMs were measured using a Gly-Pro-AMC as a substrate. Data represent the means ± S.D. of three independent experiments. (B) The vildagliptin cyano group-hydrolyzing activities in a panel of 23 individual HLMs were measured. The substrate concentration was 1 µM. Data represent the means ± S.D. of three independent experiments.
- Fig. 7.
Correlation analyses between hepatic vildagliptin cyano group-hydrolyzing activities and other drug-metabolizing enzyme activities in individual HLMs and characteristics of 23 donors. The relationships between hepatic vildagliptin cyano group-hydrolyzing activities and DPP-4 (A), arylacetamide deacetylase (B), CES1 (C), and CES2 (D) activities of individual HLMs from 23 donors are shown. The relationships between hepatic vildagliptin cyano group-hydrolyzing activities and age (E) and BMI (F) of 23 donors are also shown. The correlation analysis was performed using the Spearman rank method. Data represent the means of triplicate determinations.
Tables
- TABLE 1
Species differences of metabolite levels in plasma after oral administration
Australian public assessment report for vildagliptin, Department of Health and Ageing, Therapeutic Goods Administration, 2010 April. Available from: http://www.tga.gov.au/auspar/auspar-vildagliptin (accessed June 7, 2016).
Species Metabolite (% of Total AUC) Parental Vildagliptin M15.3 M20.2 M20.7 Human 26 8.1 9.5 56 Mouse 46 Trace 3.8 17 Rat 40 0 11 42 Dog 23 26 1.4 33 Rabbit 22 53 0.9 7.4 Monkey 20 0.8 72 4.9 - TABLE 2
AUC0–8 hours in three mouse groups following oral administration of vildagliptin (10 mg/kg)
Group Numbers AUC0–8 hours (ng × h/mL) Vildagliptin M20.7 Control mice 4 90 ± 14 26 ± 2.6 Control mice + sitagliptin (1000 mg/kg) 3 108 ± 21 8.5 ± 2.1** STZ-induced diabetic mice (day7) 3 68 ± 16 10 ± 0.8** ↵** P < 0.01 versus control mice.
Data Supplement
Files in this Data Supplement:
- Supplemental Data -
Supplemental Table 1 - Characteristics of 23 donors used in this study
Supplemental Table 2 - Primer sequences used for real-time RT-PCR analyses
Supplemental Figure 1 - Body weight (A), blood glucose (B), and plasma DPP-4 activity (C) in STZ-induced diabetic mice
Supplemental Figure 2 - Correlation analysis between hepatic vildagliptin-hydrolyzing activities and protein expression levels of CYP3A4 in individual HLMs
- Supplemental Data -
