Pourcyrous M, Leffler C, Busija D
Department of Pediatrics, University of Tennessee, Memphis 38163.
Am J Physiol. 1990 Sep;259(3 Pt 2):H662-7. doi: 10.1152/ajpheart.1990.259.3.H662.
Cerebral hemodynamics during asphyxia and reventilation were investigated in normothermic, hypothermic (35 degrees C), and indomethacin-pretreated (5 mg/kg iv) anesthetized, newborn pigs. In the normothermic group, total cerebral blood flow (CBF) measured with radioactive microspheres was 57 +/- 12 ml.min-1 x 100 g-1 during baseline, 104 +/- 19 at 1 min of asphyxia, 39 +/- 5 at 5 min of asphyxia, 186 +/- 16 at 8 min of reventilation, and 95 +/- 20 at 16 min of reventilation. During asphyxia and reventilation blood flow to brain stem was better regulated than to cerebrum or cerebellum. Baseline CBF was similar in the indomethacin and hypothermic groups (32 +/- 2 and 41 +/- 5 ml.min-1 x 100 g-1, respectively; n = 5 for each group). However, during asphyxia, blood flow was never less in either one of these groups than in the normothermic group in spite of a lack of arterial hypercapnia at 1 min in the hypothermia group. During reventilation, blood flow was sometimes lower in the hypothermic and indomethacin groups than the normothermic group but never lower when considered on a percentage change from baseline basis. We conclude that inhibition of prostanoid production with indomethacin did not limit vasodilation during these conditions.
在体温正常、体温过低（35摄氏度）以及经吲哚美辛预处理（静脉注射5毫克/千克）的麻醉新生猪身上，研究了窒息和再通气期间的脑血流动力学。在体温正常组中，用放射性微球测量的总脑血流量（CBF）在基线时为57±12毫升·分钟⁻¹×100克⁻¹，窒息1分钟时为104±19，窒息5分钟时为39±5，再通气8分钟时为186±16，再通气16分钟时为95±20。在窒息和再通气期间，脑干的血流调节比大脑或小脑更好。吲哚美辛组和体温过低组的基线CBF相似（分别为32±2和41±5毫升·分钟⁻¹×100克⁻¹；每组n = 5）。然而，在窒息期间，尽管体温过低组在1分钟时没有动脉血二氧化碳过多，但这两组中的任何一组的血流量都从未低于体温正常组。在再通气期间，体温过低组和吲哚美辛组的血流量有时低于体温正常组，但从基线变化百分比来看从未更低。我们得出结论，在这些情况下，用吲哚美辛抑制前列腺素生成并未限制血管舒张。
