PT - JOURNAL ARTICLE AU - Takayoshi Ishimori AU - Tsuneo Saga AU - Marcelo Mamede AU - Hisataka Kobayashi AU - Tatsuya Higashi AU - Yuji Nakamoto AU - Noriko Sato AU - Junji Konishi TI - Increased <sup>18</sup>F-FDG Uptake in a Model of Inflammation: Concanavalin A-Mediated Lymphocyte Activation DP - 2002 May 01 TA - Journal of Nuclear Medicine PG - 658--663 VI - 43 IP - 5 4099 - http://jnm.snmjournals.org/content/43/5/658.short 4100 - http://jnm.snmjournals.org/content/43/5/658.full SO - J Nucl Med2002 May 01; 43 AB - The aim of this project was to study a mechanism that might explain the increased uptake of 18F-labeled FDG seen in inflammation. The approach chosen was to examine the effect on 18F-FDG uptake of acute activation of murine lymphocytes by concanavalin A (Con A). Methods: Immunocompetent BALB/c mice and nude mice received an intravenous injection of 10 mg/kg Con A. Twenty-four hours later, the mice received an intravenous injection of 0.74 MBq (20 μCi) 18F-FDG. One hour later, biodistribution was determined. The distribution of the radiolabel in the liver was also evaluated by autoradiography. In vitro 18F-FDG uptake to splenocytes from BALB/c mice with and without Con A pretreatment were determined 30, 60, and 120 min after the splenocytes were mixed with 18F-FDG (0.74 MBq [20 μCi]/200 μL). Results: In immunocompetent BALB/c mice, pretreatment with Con A significantly increased 18F-FDG uptake in the spleen and liver. Autoradiographs of the liver showed that pretreatment with Con A produced a specific localization of 18F-FDG at periportal areas, where numerous sites of cellular infiltration were observed. In vitro binding of 18F-FDG to the splenocytes was significantly higher for Con A-pretreated BALB/c mice than for control mice. Conclusion: This study showed that Con A increased 18F-FDG uptake. Con A-activated lymphocytes actively took up 18F-FDG both in vitro and in vivo, and 18F-FDG specifically accumulated in Con A-mediated acute inflammatory tissues.