Wertz R L, Donaldson D J
J Embryol Exp Morphol. 1979 Oct;53:315-25.
The newt limb requires nerves for successful regeneration, but the jaw appears to be nerve independent. Among the current hypotheses for the regeneration-inhibitory action of X-rays is one proposing inactivation of nerves as the main cause. We decided to test this hypothesis by comparing the irradiation levels necessary for inhibition of limb and jaw regeneration. Jaws and left front limbs were exposed locally to doses of ionizing X-irradiation ranging from 250 to 2000 R at least 6 weeks prior to amputation of the jaw and both front limbs. After 90 days post-amputation all surviving animals were examined grossly for signs of regeneration. In addition, some of the controls and most of those receiving 250, 500 and 1000 R were processed for histological examination. All unirradiated limbs and jaws supported regeneration. Those exposed to 250 R also regenerated, but a third of the jaws were hypomorphic. At 500 R and above, neither jaws nor limbs regenerated. Since both systems were affected by similar doses of X-rays, it appears that nerves are not the primary X-ray target in adult newts.
蝾螈的肢体成功再生需要神经，但颌部的再生似乎与神经无关。在当前关于X射线抑制再生作用的假说中，有一种认为神经失活是主要原因。我们决定通过比较抑制肢体和颌部再生所需的辐射水平来验证这一假说。在切除颌部和双侧前肢至少6周前，对颌部和左前肢进行局部电离X射线照射，剂量范围为250至2000伦琴。截肢后90天，对所有存活的动物进行大体检查，观察再生迹象。此外，对一些对照组以及接受250、500和1000伦琴照射的大部分动物进行组织学检查。所有未受照射的肢体和颌部都能支持再生。接受250伦琴照射的也能再生，但三分之一的颌部发育不全。在500伦琴及以上剂量时，颌部和肢体均不再再生。由于两个系统都受到相似剂量X射线的影响，因此在成年蝾螈中，神经似乎不是X射线的主要作用靶点。
