Blood-brain barrier permeability during dopamine-induced hypertension in fetal sheep.
Blood-brain barrier permeability during dopamine-induced hypertension in fetal sheep.
复制标题
胎羊多巴胺诱导高血压期间的血脑屏障通透性。
DOI：
10.1152/jappl.2001.91.1.123
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Gleason,CA
中科院分区：
文献类型：
--
作者：
Harris,AP;Robinson,R;Koehler,RC;Traystman,RJ;Gleason,CA
多巴胺通常被用作患病新生儿的升压剂，但动脉血压的升高可能会破坏血脑屏障（BBB），特别是在早产儿中。使用定时怀孕的绵羊，我们测试的假设，多巴胺诱导的高血压增加胎儿血脑屏障通透性和脑含水量。通过在多巴胺或生理盐水输注开始后10 min静脉注射小示踪分子[14C]氨基异丁酸，评估了9个脑区（包括大脑皮质、尾状核、丘脑、脑干、小脑和脊髓）的屏障通透性。我们研究了23个长期插管的胎羊在0.6（93天，n= 10）和0.9（132天，n= 13）妊娠。静脉注射多巴胺使93天胎儿的平均动脉压从38 ± 3 mmHg增加到53 ± 5 mmHg，132天胎儿的平均动脉压从55 ± 5 mmHg增加到77 ± 8 mmHg，而动脉氧含量没有降低。这些40%的动脉压升高接近于在这些年龄的胎羊中生理应激所报告的最大高血压。在0.6或0.9妊娠期，与生理盐水对照组相比，多巴胺处理胎儿的任何脑区中均未检测到氨基异丁酸的脑转移系数显著增加。在两个年龄段，多巴胺输注也没有显着增加皮质水含量。我们的结论是，在正常氧的胎羊多巴胺输注过程中平均动脉压增加40%不会产生实质性的血脑屏障破坏或脑水肿，甚至早在0.6妊娠。
Dopamine is often used as a pressor agent in sick newborn infants, but an increase in arterial blood pressure could disrupt the blood-brain barrier (BBB), especially in the preterm newborn. Using time-dated pregnant sheep, we tested the hypothesis that dopamine-induced hypertension increases fetal BBB permeability and cerebral water content. Barrier permeability was assessed in nine brain regions, including cerebral cortex, caudate, thalamus, brain stem, cerebellum, and spinal cord, by intravenous injection of the small tracer molecule [14C]aminoisobutyric acid at 10 min after the start of dopamine or saline infusion. We studied 23 chronically catheterized fetal sheep at 0.6 (93 days,n= 10) and 0.9 (132 days,n= 13) gestation. Intravenous infusion of dopamine increased mean arterial pressure from 38 ± 3 to 53 ± 5 mmHg in 93-day fetuses and from 55 ± 5 to 77 ± 8 mmHg in 132-day fetuses without a decrease in arterial O2content. These 40% increases in arterial pressure are close to the maximum hypertension reported for physiological stresses at these ages in fetal sheep. No significant increases in the brain transfer coefficient of aminoisobutyric acid were detected in any brain region in dopamine-treated fetuses compared with saline controls at 0.6 or 0.9 gestation. There was also no significant increase in cortical water content with dopamine infusion at either age. We conclude that a 40% increase in mean arterial pressure during dopamine infusion in normoxic fetal sheep does not produce substantial BBB disruption or cerebral edema even as early as 0.6 gestation.