Turinsky J, Long C L
Department of Physiology, Albany Medical College, New York 12208.
Am J Physiol. 1990 Mar;258(3 Pt 1):E485-91. doi: 10.1152/ajpendo.1990.258.3.E485.
One hindlimb of each rat was denervated by sectioning the sciatic nerve. Three days later, soleus, plantaris, and gastrocnemius muscles of the sham hindlimb and the contralateral denervated hindlimb were excised and analyzed for intracellular concentrations of 23 free amino acids and the dipeptides carnosine and anserine. Compared with the sham soleus (slow-twitch) muscle, the sham plantaris and gastrocnemius (fast-twitch) muscles showed 57-81% lower concentrations of histidine, glutamine, glutamate, aspartate, and serine and also 32-78% lower levels of taurine, citrulline, phosphoserine, and ornithine. On the other hand the fast-twitch muscles exhibited 31% higher concentrations of free glycine and alanine and 113-127% higher levels of carnosine and anserine than the soleus muscle. The denervation caused greater changes in soleus muscle than in the other two muscles. The denervation-induced changes in soleus muscle included 38-87% increases in concentrations of free valine, leucine, isoleucine, and glutamate associated with 21-56% decreases in the levels of glutamine, glycine, aspartate, serine, alanine, and citrulline. It is concluded that both muscle fiber population and muscle denervation have an independent effect on the intracellular concentrations of free amino acids in muscles.
通过切断坐骨神经使每只大鼠的一条后肢去神经支配。三天后，切除假手术侧后肢和对侧去神经支配后肢的比目鱼肌、跖肌和腓肠肌，分析其中23种游离氨基酸以及二肽肌肽和鹅肌肽的细胞内浓度。与假手术侧的比目鱼肌（慢肌纤维）相比，假手术侧的跖肌和腓肠肌（快肌纤维）中，组氨酸、谷氨酰胺、谷氨酸、天冬氨酸和丝氨酸的浓度降低了57 - 81%，牛磺酸、瓜氨酸、磷酸丝氨酸和鸟氨酸的水平也降低了32 - 78%。另一方面，快肌纤维中的游离甘氨酸和丙氨酸浓度比比目鱼肌高31%，肌肽和鹅肌肽的水平比比目鱼肌高113 - 127%。去神经支配对比目鱼肌造成的变化比对其他两块肌肉的变化更大。去神经支配引起的比目鱼肌变化包括游离缬氨酸、亮氨酸、异亮氨酸和谷氨酸浓度增加38 - 87%，同时谷氨酰胺、甘氨酸、天冬氨酸、丝氨酸、丙氨酸和瓜氨酸水平降低21 - 56%。结论是，肌纤维类型和肌肉去神经支配对肌肉中游离氨基酸的细胞内浓度均有独立影响。
