不同酸鹼值的全靜脈營養輸液對大鼠蛋白質代謝之影響

The Effect of pH-Modified Total Parenteral Nutrition Solutions on Protein Metabolism in Rats

蔡馥安(Fu-Ann Tsai)；羅慧珍(Hui-Chen Lo)

全靜脈營養 ； 酸鹼值 ； 氮平衡 ； 胺基酸 ； total parenteral nutrition ； pH value ； nitrogen balance ； amino acid

The Changhua Journal of Medicine

6卷3期（2001 / 07 / 01）

157 - 165

繁體中文

背景：長期使用全靜脈營養(TPN)輸液的病患其氮平衡及同化作用常不盡理想，部份原因為TPN輸液代謝後產生較多的酸性物質，加上胃腸道萎縮增加鹼性物質流失，進而導致代謝平衡失調。由於正常人血液酸鹼(pH)值為7.35至7.45，而傳統TPN 輸液pH值為5.0至6.0，因此本實驗欲測試調整TPN輸液的pH值是否會影響蛋白質的代謝。 方法：大鼠經頸靜脈插管後輸予傳統TPN輸液(pH5.5, C組)，或輸予經鹽酸(pH4.5, A組)或氫氧化鈉調整(pH 6.5, B組)pH值之TPN輸液。另包括餵食塊狀飼料而未施予手術之對照組(R組)。 結果：12天後TPN大鼠體重變化量顯著低於R組。實驗期間B組大鼠雖呈現負氮平衡，但與A及C組之氮平衡於統計上無顯著差異。A組腓腸肌相對重量(克/公斤體重)顯著低於R組；B組心臟、肝臟及脾臟相對重量顯著高於R及C組，而腓腸肌相對重量顯著低於R及C組。B組血清白蛋白濃度顯著低於C組，而三酸甘油酯濃度顯著高於C組。血漿中丙胺酸、甘胺酸、甲硫胺酸及苯丙胺酸濃度以B組顯著高於R及C組。腓腸肌中丙胺酸、胱胺酸、甘胺酸、離胺酸、甲硫胺酸、酪胺酸及擷胺酸含量以A組顯著低於C組；精胺酸含量以B組顯著高於C組；甘胺酸、離胺酸、甲硫胺酸及纈胺酸含量以B組顯著低於C組。 結論：本實驗結果顯示以鹽酸或氫氧化鈉調整TPN輸液pH值，造成大鼠組織重量、代謝作用及血液和腓腸肌中胺基酸組成的改變。

Background: Patients with long-term total parenteral nutrition (TPN) infusion usually have inappropriate nitrogen balance and anabolism because of increases in acid metabolites from TPN solution and base losses from gastrointestinal hypotrophy. The physiological pH in humans is 7.35-7.45. However, the pH value of the conventional TPN solution is between 5.0 and 6.0. The aim of this study was to investigate effects of pH-modified TPN solutions on protein metabolism. Methods: Rats underwent jugular vein cannulation were infused with conventional (pH 5.5, group C), hydrochloric acid adjusted (pH 4.5, group A), or sodium hydroxide adjusted (pH 6.5, group B) TPN solution. Orally fed rats were included as references (group R). Results: After 12 days, the TPN groups had significantly lower body weight change than the R group. Animals in the B group had negative nitrogen balance, which, however, was not significantly different from that in the A or C group. The relative weights of gastrocnemius muscle (g/kg of body weight) were significantly lower in the A than in the R group. The relative weights of heart, liver and spleen were significantly greater, whereas the relative weights of gastrocnemius muscle were significantly lower in the B than in the R and C groups. The concentration of albumin in serum was significantly decreased, whereas that of triglyceride was significantly increased in the B group compared to the C group. Plasma concentrations of alanine, glycine, methionine and phenylalanine were significantly greater in the B group compared to the R and C groups. In the gastrocnemius muscle, the contents of alanine, cystine, glycine, lysine, methionine, tyrosine and valine were significantly lower in the A group compared to the C group. In the gastrocnemius muscle, the content of arginine was significantly higher and the contents of glycine, lysine, methionine and valine were significantly lower in the B group than the C group. Conclusion: Our results suggest that the pH-modified TPN solutions using hydrochloric acid or sodium hydroxide may cause changes in plasma amino acid profile, as well as changes in tissue weights, metabolism, and amino acid profile in gastrocnemius muscle.