Grigoriadis Nikolaos, Albani Maria, Simeonidou Constantina, Guiba-Tziampiri O
Laboratory of Experimental Physiology, Medical School, Aristotle University of Thessaloniki, Thessaloniki 54006, Greece.
Brain Res Dev Brain Res. 2004 Oct 15;153(1):79-87. doi: 10.1016/j.devbrainres.2004.07.015.
Muscle and peripheral nerve development is clearly dependent on their interaction during early postnatal life. Furthermore, muscle or peripheral nerve activity plays a crucial role in the maturation of the neuromuscular system. In this study, the possible involvement of spinal catecholamines in fast muscle recovery after nerve crush is investigated. Sciatic nerve crush was performed on the fourth to fifth postnatal day. Following that, L-Dopa was administered daily [150 mg/kg body weight (BW)] i.p., until the 21st day after birth. L-Dopa-treated and control groups were then examined electrophysiologically for the contractile properties of extensor digitorum longus (EDL) muscles. Two experimental groups were included in this study: (i) rats whose sciatic nerve was crushed and were treated with L-Dopa and (ii) rats whose sciatic nerve was crushed and were not treated with L-Dopa. The number of motoneurones for both groups was estimated by HRP retrograde labelling. The results showed that the operated L-Dopa-treated EDL muscles of the rats exhibited limited atrophy, slighter impairment of maximal tetanic tension, lesser resistance to fatigue, and polyneuronal innervation than the controls. The number of motoneurones was the same for the operated muscles in both groups of animals and was within the normal ranges. Our findings suggest that catecholamines of locomotion during the early stages of development may have a beneficial effect on fast muscle recovery following nerve crush. The action of L-Dopa is attributed to noradrenaline, which acts through descending spinal noradrenergic pathways, possibly via a(2)-adrenergic receptors at the spinal level.
肌肉和周围神经的发育显然依赖于它们在出生后早期的相互作用。此外，肌肉或周围神经活动在神经肌肉系统的成熟过程中起着至关重要的作用。在本研究中，研究了脊髓儿茶酚胺在神经挤压后快肌恢复中的可能作用。在出生后第4至5天进行坐骨神经挤压。之后，每天腹腔注射左旋多巴[150mg/kg体重（BW）]，直至出生后第21天。然后对左旋多巴治疗组和对照组进行电生理检查，以检测趾长伸肌（EDL）的收缩特性。本研究包括两个实验组：（i）坐骨神经被挤压并接受左旋多巴治疗的大鼠，以及（ii）坐骨神经被挤压但未接受左旋多巴治疗的大鼠。通过HRP逆行标记估计两组运动神经元的数量。结果表明，与对照组相比，接受手术并经左旋多巴治疗的大鼠EDL肌肉萎缩有限，最大强直张力受损较轻，抗疲劳能力较弱，且存在多神经元支配。两组动物手术肌肉的运动神经元数量相同，且在正常范围内。我们的研究结果表明，发育早期运动中的儿茶酚胺可能对神经挤压后的快肌恢复有有益作用。左旋多巴的作用归因于去甲肾上腺素，它通过脊髓下行去甲肾上腺素能通路起作用，可能是通过脊髓水平的α（2）-肾上腺素能受体。
