BACKGROUND: The angiotensin II type 1 receptor (AT1R) 1166A/C polymorphism is reported to be implicated in cardiovascular diseases. The association between the 1166A/C polymorphism and diastolic blood pressure (DBP) changes in response to exogenous angiotensin II and valsartan was evaluated by pharmacokinetic and pharmacodynamic modeling. METHODS: Thirteen normotensive, healthy adults (six with the 1166A/A polymorphism and seven with 1166A/C) were enrolled in this clinical study. Angiotensin II was infused continuously over a 2-min period at four different rates (from 5 ng/kg/min and increased by 5 ng/kg/min) at 0 (before valsartan dosing), 2, 4, 8, 12, and 24 h after a single oral dose of valsartan (40 mg). BP was measured serially before and at the end of each rate of angiotensin II infusion. Plasma concentration-time profiles of valsartan were established over a 24-h period. We analyzed data using NONMEM and studied the relationship between the AT1R 1166A/C genotypes and BP responses. RESULTS: Plasma valsartan concentrations and DBP data best fitted into a two-compartment linear model and E(max) model (E(max) with baseline for angiotensin II and inhibitory E(max) for valsartan), respectively. The ED50 for angiotensin II in the subjects with 1166A/C [95% confidence interval (CI): 4.30 approximately 14.02 ng/kg/min] was significantly lower than in those with 1166A/A (95% CI: 14.23 approximately 28.77 ng/kg/min), while the E(max) for angiotensin II and EC50 for valsartan was similar in both genotype groups. CONCLUSIONS: These results suggest that exogenous human angiotensin II increases the BP more potently in subjects with 1166A/C than in those with 1166A/A.
BACKGROUND: The angiotensin II type 1 receptor (AT1R) 1166A/C polymorphism is reported to be implicated in cardiovascular diseases. The association between the 1166A/C polymorphism and diastolic blood pressure (DBP) changes in response to exogenous angiotensin II and valsartan was evaluated by pharmacokinetic and pharmacodynamic modeling. METHODS: Thirteen normotensive, healthy adults (six with the 1166A/A polymorphism and seven with 1166A/C) were enrolled in this clinical study. Angiotensin II was infused continuously over a 2-min period at four different rates (from 5 ng/kg/min and increased by 5 ng/kg/min) at 0 (before valsartan dosing), 2, 4, 8, 12, and 24 h after a single oral dose of valsartan (40 mg). BP was measured serially before and at the end of each rate of angiotensin II infusion. Plasma concentration-time profiles of valsartan were established over a 24-h period. We analyzed data using NONMEM and studied the relationship between the AT1R1166A/C genotypes and BP responses. RESULTS: Plasma valsartan concentrations and DBP data best fitted into a two-compartment linear model and E(max) model (E(max) with baseline for angiotensin II and inhibitory E(max) for valsartan), respectively. The ED50 for angiotensin II in the subjects with 1166A/C [95% confidence interval (CI): 4.30 approximately 14.02 ng/kg/min] was significantly lower than in those with 1166A/A (95% CI: 14.23 approximately 28.77 ng/kg/min), while the E(max) for angiotensin II and EC50 for valsartan was similar in both genotype groups. CONCLUSIONS: These results suggest that exogenous humanangiotensin II increases the BP more potently in subjects with 1166A/C than in those with 1166A/A.
Authors: P B Timmermans; P C Wong; A T Chiu; W F Herblin; P Benfield; D J Carini; R J Lee; R R Wexler; J A Saye; R D Smith Journal: Pharmacol Rev Date: 1993-06 Impact factor: 25.468
Authors: K Kainulainen; M Perola; J Terwilliger; J Kaprio; M Koskenvuo; A C Syvänen; E Vartiainen; L Peltonen; K Kontula Journal: Hypertension Date: 1999-03 Impact factor: 10.190
Authors: J L Dieguez-Lucena; P Aranda-Lara; M Ruiz-Galdón; J García-Villanova; M Morell-Ocaña; A Reyes-Engel Journal: Hypertension Date: 1996-07 Impact factor: 10.190
Authors: P P van Geel; Y M Pinto; A A Voors; H Buikema; M Oosterga; H J Crijns; W H van Gilst Journal: Hypertension Date: 2000-03 Impact factor: 10.190