Kinderman N B, Jones K J
Department of Physical Therapy, University of Illinois at Chicago 60612.
Exp Neurol. 1994 Mar;126(1):144-8. doi: 10.1006/exnr.1994.1051.
Following facial nerve injury, female hamster facial motoneurons (HFMN) regenerate faster than their male counterparts. Testosterone propionate (TP) markedly accelerates the rate of facial nerve regeneration in males, but has a relatively reduced effect in females. In the present study, we utilized in situ hybridization in conjunction with ribosomal DNA probes to test the hypothesis that in females HFMN axotomy produces a less dramatic cell body response than in males and to examine gender differences in the effects of steroids on peripheral nerve regeneration at the molecular level. The results indicate that in females axotomy alone induced moderate increases in rRNA levels, beginning 2 days postoperatively. These changes were both slower in onset and lower in magnitude than those in the males. TP augmented the effects of axotomy on rRNA levels at the later postoperative times. There were no early, rapid effects of TP, like those observed in males. These molecular data substantiate our previous findings of inherent sex differences in neuronal regeneration and the ability of gonadal steroids to augment the reparative response of peripheral neurons to injury.
面神经损伤后，雌性仓鼠的面神经运动神经元（HFMN）比雄性的再生速度更快。丙酸睾酮（TP）显著加快了雄性面神经的再生速度，但对雌性的作用相对较小。在本研究中，我们结合核糖体DNA探针进行原位杂交，以验证以下假设：雌性HFMN轴突切断后产生的胞体反应比雄性的反应程度小，并在分子水平上研究类固醇对周围神经再生影响的性别差异。结果表明，在雌性中，仅轴突切断就会导致rRNA水平适度升高，术后2天开始出现。这些变化在开始时间上比雄性慢，且幅度比雄性小。TP在术后较晚时间增强了轴突切断对rRNA水平的影响。TP没有像在雄性中观察到的那样产生早期快速效应。这些分子数据证实了我们之前关于神经元再生中固有性别差异以及性腺类固醇增强周围神经元对损伤修复反应能力的研究结果。
