TY - JOUR T1 - Elevated <sup>18</sup>F-FDG Levels in Blood and Organs After Angiotensin II Receptor Blocker Administration: Experiment in Mice Administered Telmisartan JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1384 LP - 1388 DO - 10.2967/jnumed.111.100248 VL - 54 IS - 8 AU - Yan Zhao AU - Songji Zhao AU - Yuji Kuge AU - Nagara Tamaki Y1 - 2013/08/01 UR - http://jnm.snmjournals.org/content/54/8/1384.abstract N2 - Angiotensin II receptor blockers (ARBs) are a common treatment for hypertensive patients but affect renal function. In this study, the effects of ARB on 18F-FDG distribution and excretion were examined in mice treated with telmisartan at different doses. Methods: Male C57BL/6J mice were given telmisartan (low-dose group, 0.33 mg/kg/d; moderate-dose group, 0.66 mg/kg/d; high-dose group, 3 mg/kg/d) mixed in a high-fat diet for 20 wk. Mice on a telmisartan-free diet served as the control. At designated time points, the mice were injected with 18F-FDG (18.5 MBq/mouse, n = 5–10/time point for each group) to examine its biodistribution. Autoradiography using kidney sections was performed to visualize 18F-FDG excretion. Plasma blood urea nitrogen (BUN) and creatinine levels were also measured to evaluate renal function. Results: Twenty-week telmisartan treatment significantly and dose-dependently increased 18F-FDG levels in the blood (percentage injected dose per gram of tissue normalized by animal body weight: low, 0.13 ± 0.03 [P &lt; 0.0083]; moderate, 0.15 ± 0.01 [P &lt; 0.0083]; high, 0.15 ± 0.03 [P &lt; 0.0083], vs. control, 0.09 ± 0.01). Significantly increased 18F-FDG levels in organs were observed in mice in the moderate- and high-dose groups but not in the low-dose group. The plasma BUN and creatinine levels also dose-dependently increased, but they were within the reference ranges (for BUN: low, 27.00 ± 4.42 mg/dL; moderate, 28.40 ± 2.70 mg/dL; high, 39.22 ± 6.91 mg/dL [P &lt; 0.0083], vs. control, 22.40 ± 2.80 mg/dL. For creatinine: low, 0.28 ± 0.11 mg/dL; moderate, 0.40 ± 0.07 mg/dL [P &lt; 0.0083]; high, 0.51 ± 0.09 mg/dL [P &lt; 0.0083], vs. control, 0.18 ± 0.04 mg/dL). The blood 18F-FDG level positively correlated with plasma BUN (r = 0.48, P &lt; 0.01) and creatinine (r = 0.61, P &lt; 0.01) levels. The 18F-FDG levels in the blood and organs returned to baseline 3 wk after cessation of telmisartan treatment. Autoradiography indicated that renal 18F-FDG excretion was attenuated by telmisartan treatment and was reversed after treatment cessation. Conclusion: 18F-FDG levels in the blood and organs were significantly increased by telmisartan treatment, indicating a potential increase in background activity on PET imaging of patients treated with ARBs. Our findings indicate the need for a careful assessment of 18F-FDG uptake in patients treated with ARBs. A brief cessation of ARB treatment may be a potential method to avoid these effects and solve this problem. ER -