期刊
NUCLEAR MEDICINE AND BIOLOGY
卷 39, 期 8, 页码 1232-1235出版社
ELSEVIER SCIENCE INC
DOI: 10.1016/j.nucmedbio.2012.06.012
关键词
Telmisartan; Angiotensin II type 1 receptor blocker; Positron emission tomography; Rhesus macaque
资金
- Astellas Pharma Inc.
Introduction: Telmisartan is a widely used, long-acting antihypertensive agent. Known to be a selective angiotensin II type 1 (AT(1)) receptor (AT(1)R) blocker (ARB), telmisartan acts as a partial agonist of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) and inhibits centrally mediated effects of angiotensin II in rats following peripheral administration, although the brain penetration of telmisartan remains unclear. We investigated the brain concentration and localization of telmisartan using C-11-labeled telmisartan and positron emission tomography (PET) in conscious rhesus macaques. Methods: Three male rhesus macaques were bolus intravenously administered [C-11]telmisartan either alone or as a mixture with unlabeled telmisartan (1 mg/kg). Dynamic PET images were acquired for 95 min following administration. Blood samples were collected for the analysis of plasma concentration and metabolites, and brain and plasma concentrations were calculated from detected radioactivity using the specific activity of the administered drug preparation, in which whole blood radioactivity was used for the correction of intravascular blood radioactivity in brain. Results: Telmisartan penetrated into the brain little but enough to block AT(1)R and showed a consistently increasing brain/plasma ratio within the PET scanning period, suggesting slow clearance of the compound from the brain compared to the plasma clearance. Brain/plasma ratios at 30, 60, and 90 min were 0.06, 0.13, and 0.18, respectively. No marked localization according to the AT(1)R distribution was noted over the entire brain, even on tracer alone dosing. Conclusions: Telmisartan penetrated into the brain enough to block AT(1)R and showed a slow clearance from the brain in conscious rhesus macaques, supporting the long-acting and central responses of telmisartan as a unique property among ARBs. (C) 2012 Elsevier Inc. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据