Bailey P M, Dempsey D T, Crosby L O, Mullen J L, Buzby G P
J Surg Res. 1985 May;38(5):530-6. doi: 10.1016/0022-4804(85)90072-1.
"Nonrestraining" superior vena cava (SVC) cannulae are commonly used in rat metabolic studies. The objective of this study was to evaluate the level of stress and metabolic alterations associated with surgical placement and subsequent maintenance and use of an indwelling intravenous cannula as measured by resting energy expenditure (REE), respiratory quotient (RQ), urinary nitrogen excretion, and substrate utilization pattern. Nine rats underwent SVC cannulation and six rats underwent sham operation. Postoperatively, animals were starved for 48 hr and then refed either parenterally or orally for 48 hr. Sham-operated animals adapted appropriately to starvation within 24 hr by decreasing REE 14% and increasing utilization of fat (RQ:0.89----0.78). Hypometabolic adaptation to starvation was delayed in cannulated animals until the second postoperative day, but appropriate alterations in energy substrate utilization were not affected by the presence of cannulae. Cannulae did not affect the metabolic response to oral refeeding with similar increases in REE and similar patterns of substrate utilization in sham-operated and cannulated animals. Animals refed parenterally demonstrated higher REE and apparent fat deposition (RQ greater than 1) consistent with continuous hypercaloric glucose administration. Urinary nitrogen excretion was not affected by the presence of cannulae. Cannula-associated metabolic alterations are minimal and transient and do not preclude detection and quantification of alterations associated with composition or utilization of exogenous substrates.
“非约束性”上腔静脉（SVC）插管常用于大鼠代谢研究。本研究的目的是评估与留置静脉插管的手术放置及随后的维持和使用相关的应激水平和代谢改变，通过静息能量消耗（REE）、呼吸商（RQ）、尿氮排泄和底物利用模式来衡量。9只大鼠接受了SVC插管，6只大鼠接受了假手术。术后，动物禁食48小时，然后通过肠外或口服方式再喂养48小时。假手术动物在24小时内通过将REE降低14%并增加脂肪利用（RQ：0.89 ---- 0.78）适当适应了饥饿。插管动物对饥饿的低代谢适应延迟到术后第二天，但能量底物利用的适当改变不受插管存在的影响。插管不影响对口服再喂养的代谢反应，假手术和插管动物的REE增加相似，底物利用模式相似。肠外再喂养的动物表现出更高的REE和明显的脂肪沉积（RQ大于1），这与持续给予高热量葡萄糖一致。尿氮排泄不受插管存在的影响。与插管相关的代谢改变是最小的且短暂的，并不妨碍检测和量化与外源性底物的组成或利用相关的改变。
