[Carbon-11 labeled diacylglycerol for signal transduction imaging: effect of the solubilizer on the distribution and radiation dosimetry].
Carbon-11 labeled diacylglycerol (11C-DAG) has been developed as a signal transduction imaging agent for the CNS, and it can visualize the second messenger. For clinical application by positron CT (PET), the 11C-DAG solution must be prepared for intravenous injection. However, the 11C-DAG does not dissolve in water because of its lipophilicity and requires a solubilizer such as human serum albumin (HSA) and Tween 80 (TW-80). We examined the influence of these solubilizers on the tissue distribution of 11C-DAG, and estimated the radiation dosimetry. In the brain, uptake of 11C-DAG dissolved with HSA was 1.3-1.8 times higher than that of dissolved with TW-80. On the other hand, the lung and spleen showed a higher uptake of 11C-DAG using TW-80 than when using HSA. Especially, the lungs showed 20-40 times higher uptake than when using HSA. Also, the washout of radioactivity from tissue was slower, and the dose of radiation exposure was estimated to be higher, with TW-80 than with HSA. Therefore, between TW-80 and HSA with different solubilizing mechanisms, the later was suggested to be a better solubilizer of 11C-DAG.
Fujii
R
R
Nishijin Hospital.
Imahori
Y
Y
Ido
T
T
Wakita
K
K
Horii
H
H
Yagyu
T
T
Higashi
N
N
Mabuchi
H
H
Ohmori
Y
Y
Ueda
S
S
D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D002250:Carbon Radioisotopes / Q000493:pharmacokinetics; D004075:Diglycerides / Q000493:pharmacokinetics; D006801:Humans; D011136:Polysorbates / Q000494:pharmacology*; D011874:Radiometry; D015290:Second Messenger Systems; D012709:Serum Albumin / Q000494:pharmacology*; D015398:Signal Transduction; D014055:Tomography, Emission-Computed
D002250:Carbon Radioisotopes; D004075:Diglycerides; D011136:Polysorbates; D012709:Serum Albumin