Albina J E, Henry W, King P A, Shearer J, Mastrofrancesco B, Goldstein L, Caldwell M D
Am J Physiol. 1987 Jan;252(1 Pt 1):E49-56. doi: 10.1152/ajpendo.1987.252.1.E49.
Wounding with lambda-carrageenan results in a marked decrease in the intracellular-free glutamine content of rat skeletal muscle. The potential mechanisms for this finding, including alterations in glutamine release, glutamine utilization, and glutamine synthesis, were investigated in rats under pentobarbital anesthesia. Wounding did not increase glutamine release from muscle during incubation or isolated hindlimb perfusion. Wounded muscle utilized more glutamine than nonwounded muscle, as measured both by the production of [14C]O2 and of -glutamate from labeled glutamine. Maximal glutamine synthetase activity was increased by wounding. The increase in glutamine synthetase activity in wounded muscle was prevented by adrenalectomy and restored by replacement doses of corticosterone in wounded adrenalectomized animals. The decrease in muscle free glutamine induced by wounding is therefore not mediated by an increase in the release of this amino acid, nor by a reduction in the tissue capacity for glutamine synthesis, but by an increase in glutamine utilization at the site of injury. This difference is apparently determined by the utilization of glutamine by the cellular components of the inflammatory infiltrate, which were shown to be capable of active glutaminolysis.
用λ-角叉菜胶致伤会导致大鼠骨骼肌细胞内游离谷氨酰胺含量显著降低。在戊巴比妥麻醉的大鼠中研究了这一发现的潜在机制，包括谷氨酰胺释放、谷氨酰胺利用和谷氨酰胺合成的改变。在孵育或离体后肢灌注期间，致伤并未增加肌肉中谷氨酰胺的释放。通过标记谷氨酰胺产生的[14C]O2和γ-谷氨酸来衡量，受伤肌肉比未受伤肌肉消耗更多的谷氨酰胺。致伤使谷氨酰胺合成酶的最大活性增加。肾上腺切除可阻止受伤肌肉中谷氨酰胺合成酶活性的增加，而给受伤的肾上腺切除动物补充皮质酮可使其恢复。因此，致伤引起的肌肉游离谷氨酰胺减少不是由该氨基酸释放增加介导的，也不是由谷氨酰胺合成的组织能力降低介导的，而是由损伤部位谷氨酰胺利用增加介导的。这种差异显然是由炎症浸润的细胞成分对谷氨酰胺的利用决定的，这些细胞成分被证明能够进行活跃的谷氨酰胺分解代谢。
