多巴是肾上腺内合成儿茶酚胺以及黑色素瘤内合成黑色素的前体物质，以氚标记后，它在肾上腺和黑色素瘤中的浓集

[1

2]

，是否可以抑制肾上腺肿瘤和黑色素瘤的生长，至今尚无明确结论。氚的

β

射线最大能量为18.6keV，在组织中射程为6

μ

m，小于动物体内细胞的直径。注入体内的氚标记物可浓集于某种恶性肿瘤，在瘤内或瘤细胞内放出

β

射线，使瘤细胞受到辐射损伤，从而达到抑制肿瘤生长的目的。本文是我们在这方面进行探索的初步尝试。它包括氚标记多巴在小鼠脏器内和黑色素瘤内分布的动力学观察和对黑色素瘤生长的影响的初步观察。

The in vivo kinetic distribution of [2

5

6-

3

H]-DL-DOPA

synthesized by us was investigated in mice. The experimental data showed that the radioactivity in adrenals and melanoma were high

and the eliminations from these tissues were slow. At 6 days after intravenous injection

the tissue uptakes were 2—4 times of other organs. But at such target/non-target ratio

the tumor can't be inhibited without other organs recieving doses exceeding maximum permissible level.