Cevese A, Schena F, Poltronieri R, Cerutti G
Institute of Human Physiology, University of Verona, Italy.
Cardioscience. 1995 Mar;6(1):59-64.
Treatment with propionyl-L-carnitine has been shown to increase the walking capacity of patients with peripheral vascular disease, but the mechanisms responsible for the effect are unknown. To study the effects of propionyl-L-carnitine on musculocutaneous vascular beds and the related mechanisms, a preparation of constant-pressure blood-perfused dog hind-limb was used. Since the propionyl-L-carnitine solution had a pH less than 4 the contralateral limb simultaneously received acidified saline. The substances were injected into the perfused arteries in 2 minutes or in 20 minutes, and the cumulative dose of propionyl-L-carnitine was 20 mg/kg for each administration. The preparation was well suited for this study, because there were no major systemic effects of propionyl-L-carnitine, nor signs of cross-circulation between the isolated limbs. Propionyl-L-carnitine increased flow by 130% in 2 minute infusions and by 49% in 20 minute infusions. Acidified saline increased flow by 47% in 2 minute infusions and by 34% in 20 minute infusions. The difference between propionyl-L-carnitine and acidified saline was significant in 2 minute infusions. The 2 minute infusions of propionyl-L-carnitine increased venous PO2 by 34% and PCO2 by 22% while pH decreased by 0.07. The 20 minute infusions of propionyl-L-carnitine increased PO2 by 22% and PCO2 by 24% while pH decreased 0.10 units. Acidified saline increased only venous PO2 in 2 minute infusions (16%). Calculated oxygen consumption of the perfused limbs increased in 2 minute infusions of propionyl-L-carnitine, but not significantly. It was concluded that propionyl-L-carnitine has a direct vasodilator effect in musculocutaneous vascular beds at high doses and probably enhances tissue metabolism.
已证明用丙酰-L-肉碱治疗可提高外周血管疾病患者的行走能力，但其作用机制尚不清楚。为了研究丙酰-L-肉碱对肌皮血管床的影响及其相关机制，使用了恒压血液灌注犬后肢的制备模型。由于丙酰-L-肉碱溶液的pH值小于4，对侧肢体同时接受酸化盐水。将这些物质在2分钟或20分钟内注入灌注动脉，每次给药时丙酰-L-肉碱的累积剂量为20mg/kg。该制备模型非常适合这项研究，因为丙酰-L-肉碱没有明显的全身作用，分离的肢体之间也没有交叉循环的迹象。丙酰-L-肉碱在2分钟输注时使血流量增加130%，在20分钟输注时增加49%。酸化盐水在2分钟输注时使血流量增加47%，在20分钟输注时增加34%。丙酰-L-肉碱和酸化盐水之间的差异在2分钟输注时具有统计学意义。丙酰-L-肉碱2分钟输注使静脉血氧分压升高34%，二氧化碳分压升高22%，而pH值下降0.07。丙酰-L-肉碱20分钟输注使血氧分压升高22%，二氧化碳分压升高24%，而pH值下降0.10单位。酸化盐水仅在2分钟输注时增加静脉血氧分压（16%）。灌注肢体的计算耗氧量在丙酰-L-肉碱2分钟输注时增加，但不显著。得出的结论是，高剂量的丙酰-L-肉碱在肌皮血管床中具有直接血管舒张作用，并且可能增强组织代谢。
