Measurement of skin protein breakdown in a rat model.
Measurement of skin protein breakdown in a rat model.
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测量大鼠模型中皮肤蛋白质的分解。
DOI：
10.1152/ajpendo.2000.279.4.e900
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Wolfe,RR
中科院分区：
文献类型：
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作者：
Volpi,E;Jeschke,MG;Herndon,DN;Wolfe,RR
虽然皮肤蛋白质合成可以用不同的方法测量，但没有一种可能适用于人类的方法可用于测量皮肤蛋白质分解。为此，我们在大鼠模型中使用最初用于测量肌肉蛋白质分解的稳定同位素方法（痕量释放法）测量混合皮肤分数蛋白质分解（FBR）。同时测定皮肤混合蛋白和胶原蛋白分数合成率（FSR）。开始连续输注1 -[ring-2H5]苯丙氨酸和α-[5,5,5- 2h3]酮异己酸酯（KIC） 6小时。在平台（5 - 6小时）和停止输注后的衰变期间，测量动脉和皮肤的苯丙氨酸和亮氨酸游离浓度。苯丙氨酸组皮肤FBR （%/h）为0.260±0.011，KIC/亮氨酸组为0.201±0.032 [P=无统计学意义（NS）]。苯丙氨酸组混合皮肤FSR （%/h）为0.169±0.055，KIC/亮氨酸组为0.146±0.020 （P= NS）。胶原蛋白FSR为0.124±0.023%/h （P= NS vs.混合蛋白FSR）。微量释放法是测定皮肤蛋白质分解的灵敏方法；然而，考虑到FSR的高度主体间变异性，计算皮肤净平衡是不可取的。
Whereas skin protein synthesis can be measured with different approaches, no method potentially applicable in humans is available for measurement of skin protein breakdown. To that end, we measured mixed skin fractional protein breakdown (FBR) in a rat model by use of a stable isotope method (tracee release method) originally developed to measure muscle protein breakdown. Skin mixed protein and collagen fractional synthesis rates (FSR) were also measured. A primed continuous infusion ofl-[ring-2H5]phenylalanine and α-[5,5,5-2H3]ketoisocaproate (KIC) was given for 6 h. Arterial and skin phenylalanine and leucine free enrichments were measured at plateau (5–6 h) and during the decay that followed after the infusion was stopped. Skin FBR (%/h) was 0.260 ± 0.011 with phenylalanine and 0.201 ± 0.032 with KIC/leucine [P= not significant (NS)]. Mixed skin FSR (%/h) was 0.169 ± 0.055 with phenylalanine and 0.146 ± 0.020 with KIC/leucine (P= NS). Collagen FSR was 0.124 ± 0.023%/h (P= NS vs. mixed protein FSR). The tracee release method is a sensitive method for measurement of skin protein breakdown; however, given the high intersubject variability of FSR, the calculation of skin net balance is not advisable.