^（131）Ⅰ—MIBG比活度对鼠心肌交感神经囊泡内外摄取的影响

Intra- and extravesicular accumulation as function of ￣(131)I-MIBG specific activity in mouse heart

研究了两种比活度的１３１Ⅰ－ＭＩＢＧ在正常及利血平抑制后在鼠体内的分布，结果表明：注射后４ｈ，正常鼠心肌对３．２２ＴＢｑ／ｇ的ＭＩＢＧ摄取为９．０８％ＩＤ／ｇ，明显高于对１８．５ＧＢｑ／ｇ的摄取（４．８７％ＩＤ／ｇ）。计算表明，比活度主要影响了鼠心肌交感神经囊泡内摄取，而与囊泡外摄取无关．当ＭＩＢＧ用于心肌显像时，高比活度的ＭＩＢＧ有利于诊断。

Higher and lower specific activity 131I-MIBG were investigated in normal andreserpinized mice. Biodistribution studies showed a higher uptake of 131I-MIBG in heart with its maXimum of 9.08%ID/g at 4h pi at 3.22TBq/g MIBG,and a lower uptake of 4.8%ID/g at the same take at 18.5GBq/g MIBG. The heart intravesicular uptake is increased with upping specific activity, but the heart extravesicular uptake seems not connect with specific activity. When using MIBG for myocardical imaging,a higher specific activity of 131I-MIBG will be beneficial to diagnosis.