Ullman M, Alameddine H, Skottner A, Oldfors A
Department of Pathology, University of Gothenburg, Sweden.
Acta Physiol Scand. 1989 Apr;135(4):537-43. doi: 10.1111/j.1748-1716.1989.tb08613.x.
The effects of human recombinant growth hormone (rhGH) on regenerating skeletal muscle after ischaemic necrosis and on denervated skeletal muscle were studied in normal adult rats. One group of rats was treated with 4 IE rhGH daily by subcutaneous injections, while control rats were injected with saline. The treatment with rhGH resulted in increased levels of insulin-like growth factor-I (IGF-I) in serum. Ischaemic necrosis was achieved in the extensor digitorum longus (EDL) muscle by cutting the supplying vessels and nerve fascicles at the entrance into the muscle. The wet weight and DNA: protein ration in the regenerating muscle were determined 2 and 4 weeks after the operation. The weight of the regenerating muscles in the rats treated with rhGH during the period of study was larger than in the control rats, while the DNA:protein ratio did not differ significantly between the groups. Denervation of the EDL and soleus muscles followed by subsequent reinnervation was obtained by freezing the sciatic nerve with a forceps chilled in liquid nitrogen. Rats treated with rhGH during the period of denervation and reinnervation, i.e. during the 4 weeks after the freezing of the sciatic nerve, revealed increased weight of both the reinnervated and normal muscles compared to corresponding muscles of control rats. Denervation of the EDL and soleus muscles without subsequent reinnervation was achieved by cutting the sciatic nerve at the level of the thigh. Four weeks after denervation the muscles showed atrophy, mainly affecting type 2 fibres in the EDL muscle and both type 1 and type 2 fibres in the soleus muscle.
在正常成年大鼠中研究了重组人生长激素（rhGH）对缺血性坏死后再生骨骼肌以及失神经支配骨骼肌的影响。一组大鼠每天皮下注射4国际单位的rhGH，而对照大鼠注射生理盐水。rhGH治疗导致血清中胰岛素样生长因子-I（IGF-I）水平升高。通过切断趾长伸肌（EDL）进入肌肉处的供应血管和神经束来造成缺血性坏死。在手术后2周和4周测定再生肌肉的湿重和DNA：蛋白质比率。在研究期间接受rhGH治疗的大鼠中，再生肌肉的重量大于对照大鼠，而两组之间的DNA：蛋白质比率没有显著差异。通过用在液氮中冷却的镊子冷冻坐骨神经，使EDL和比目鱼肌失神经支配，随后再进行神经再支配。在失神经支配和再支配期间，即在冷冻坐骨神经后的4周内接受rhGH治疗的大鼠，与对照大鼠的相应肌肉相比，再支配肌肉和正常肌肉的重量均增加。通过在大腿水平切断坐骨神经，实现EDL和比目鱼肌的失神经支配且不进行后续再支配。失神经支配4周后，肌肉出现萎缩，主要影响EDL肌肉中的2型纤维以及比目鱼肌中的1型和2型纤维。
