Accili E A, Puttaswamaiah S, Lioy F
Department of Physiology, University of British Columbia, Vancouver, Canada.
J Auton Nerv Syst. 1988 Aug;23(2):87-94. doi: 10.1016/0165-1838(88)90072-0.
A cervical (C2) spinal section was carried out in anaesthetized, neuromuscularly blocked cats and the vascularly isolated hindlimbs were independently perfused at constant flow with blood taken from the abdominal aorta. One leg was denervated by sectioning the lumbar sympathetic chain. The animals were hyperventilated in 100% O2 and 5% or 10% CO2 in O2 was administered without altering the rate or tidal volume of the respirator. Increasing paCO2 (mm Hg) from 16.36 +/- 0.84 to 37.48 +/- 1.03 and to 62.23 +/- 2.23, induced a significant early vasoconstriction (P1) followed by a later more prolonged vasoconstriction (P2) in the innervated leg, while only a significant P2 response was present in the sympathetically denervated leg. A significant increase in systemic arterial pressure (SAP) was also observed with no change in heart rate (HR). After bilateral adrenalectomy increasing paCO2 from 17.16 +/- 0.66 to 37.96 +/- 1.21 and to 64.20 +/- 1.55, induced smaller but significant P1 and P2 responses in the innervated leg but only a significant P2 response was induced in the denervated leg. These results suggest that the early vasoconstriction was mainly due to activation of lumbar sympathetic neurons, while the late vasoconstriction was caused by the release of adrenal catecholamines and possibly other unidentified vasoconstrictor substances.
在麻醉且神经肌肉阻滞的猫身上进行颈（C2）脊髓切断术，对血管分离的后肢以恒定流量独立灌注取自腹主动脉的血液。通过切断腰交感神经链使一条腿去神经支配。动物在100%氧气中过度通气，然后给予5%或10%二氧化碳与氧气的混合气体，同时不改变呼吸机的速率或潮气量。将动脉血二氧化碳分压（paCO2，mmHg）从16.36±0.84升高至37.48±1.03，再升高至62.23±2.23，在有神经支配的腿中诱发了显著的早期血管收缩（P1），随后是更持久的晚期血管收缩（P2），而在交感神经去支配的腿中仅出现显著的P2反应。还观察到全身动脉压（SAP）显著升高，而心率（HR）无变化。双侧肾上腺切除术后，将paCO2从17.16±0.66升高至37.96±1.21，再升高至64.20±1.55，在有神经支配的腿中诱发了较小但显著的P1和P2反应，而在去神经支配的腿中仅诱发了显著的P2反应。这些结果表明，早期血管收缩主要是由于腰交感神经元的激活，而晚期血管收缩是由肾上腺儿茶酚胺以及可能其他未确定的血管收缩物质的释放引起的。
