Hakim T S, Petrella J
Department of Physiology, McGill University, Montréal, Qué., Canada.
Can J Physiol Pharmacol. 1988 Apr;66(4):396-401. doi: 10.1139/y88-066.
The effects of acute administration of therapeutic doses (1-10 mg/kg) of pentoxifylline and aminophylline on the resistance of the systemic and pulmonary circuits in anaesthetized dogs and pigs were tested. During room air breathing, neither of the two substances caused a significant change in systemic vascular resistance (SVR) or pulmonary vascular resistance (PVR). During hypoxia (10% O2 and nitrogen), however, both substances caused a significant reduction in PVR (p less than 0.05) without affecting SVR. The largest dose of pentoxifylline decreased PVR from 7.8 +/- 2.8 to 4.4 +/- 1.5 in dogs and from 9.9 +/- 1.4 to 5.8 +/- 0.6 mmHg.L-1.min in pigs. Aminophylline was equally effective and selective in lowering PVR but not SVR during hypoxia. When SVR was elevated in dogs by continuous infusion of angiotensin, pentoxifylline lowered SVR from 139 +/- 27 to 83 +/- 20 mmHg.L-1.min (p less than 0.05). The simultaneous small elevation in PVR during angiotensin infusion was also attenuated to base-line value by pentoxifylline injection. These results suggest that xanthines, in therapeutic doses, can have a profound vasodilator effect on either the systemic or on the pulmonary circuit, only wherever the vessels are constricted. The vasodilatory effect of pentoxifylline is viewed as a second beneficial effect besides the benefit derived from its action on erythrocyte deformability.
测试了治疗剂量（1 - 10毫克/千克）的己酮可可碱和氨茶碱急性给药对麻醉犬和猪体循环及肺循环阻力的影响。在呼吸室内空气期间，这两种物质均未引起体循环血管阻力（SVR）或肺循环血管阻力（PVR）的显著变化。然而，在低氧（10%氧气和氮气）期间，这两种物质均导致PVR显著降低（p小于0.05），而不影响SVR。己酮可可碱的最大剂量使犬的PVR从7.8±2.8降至4.4±1.5，猪的PVR从9.9±1.4降至5.8±0.6 mmHg·L⁻¹·min。氨茶碱在低氧期间降低PVR但不影响SVR方面同样有效且具有选择性。当通过持续输注血管紧张素使犬的SVR升高时，己酮可可碱使SVR从139±27降至83±20 mmHg·L⁻¹·min（p小于0.05）。己酮可可碱注射还使血管紧张素输注期间同时出现的PVR小幅升高减弱至基线值。这些结果表明，治疗剂量的黄嘌呤仅在血管收缩的情况下，可对体循环或肺循环产生显著的血管舒张作用。己酮可可碱的血管舒张作用被视为除其对红细胞变形能力的作用所带来的益处之外的第二个有益作用。
