Response of cerebral blood flow to changes in PCO2 in fetal, newborn, and adult sheep.
Response of cerebral blood flow to changes in PCO2 in fetal, newborn, and adult sheep.
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胎儿、新生儿和成年羊脑血流量对 PCO2 变化的反应。
DOI：
10.1152/ajpheart.1982.242.5.h862
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
Molteni,RA
中科院分区：
文献类型：
--
作者：
Rosenberg,AA;JonesJr,MD;Traystman,RJ;Simmons,MA;Molteni,RA
在未麻醉的胎羊、新生羊和成年羊中，研究了脑血流量（Qc）和脑氧消耗（cmoo2）对CO2张力变化的反应对发育的影响。使用放射性微球技术测量血流量。cmoo2计算为Qc与动脉和矢状窦血氧含量之差（CaO2—CVO2）的乘积。Qc对动脉CO2张力变化的反应从胎儿[3.53 +/- 0.56 ml.100 g-1 min-1 mmhg PaCO2(-1) (SE)]到新生儿（5.16 +/- 0.59）到成人（6.20 +/- 0.63）增加。只有胎儿与成人的差异有统计学意义（P < 0.05）。有研究表明，脑血流CO2反应性的发育差异是cmor2差异的结果。我们通过观察变量1/（CaO2—CVO2）对CO2的响应来纠正cmoo2的差异。根据菲克原理1/(CaO2—CVO2) = Qc/ cmoro2，即单位耗氧量的血流量。胎儿反应与新生儿无显著差异，但成人反应与新生儿无显著差异（P < 0.05）。因此，胎儿和成人脑血流中CO2反应的差异不能用cmor2的差异来解释。
Developmental effects on the response of cerebral blood flow (Qc) and cerebral O2 consumption (CMRO2) to changes in CO2 tension were assessed in unanesthetized fetal, newborn, and adult sheep. Blood flow was measured using the radioactive microsphere technique. CMRO2 was calculated as the product of Qc and the difference in O2 content between arterial and sagittal sinus blood (CaO2 -- CVO2). The response of Qc to changes in arterial CO2 tension increased from fetus [3.53 +/- 0.56 ml.100 g-1.min-1.mmHg PaCO2(-1) (SE)] to newborn (5.16 +/- 0.59) to adult (6.20 +/- 0.63). Only the fetal-adult difference was significant (P less than 0.05). It has been suggested that developmental differences in CO2 responsiveness of cerebral blood flow are the result of differences in CMRO2. We corrected for differences in CMRO2 by looking at the response to CO2 of the variable 1/(CaO2--CVO2). According to the Fick principle 1/(CaO2--CVO2) = Qc/CMRO2, i.e., blood flow per unit O2 consumption. The fetal response was not significantly different from the newborn, but the adult was significantly different from both (P less than 0.05). Thus the difference in CO2 response of cerebral blood flow between fetus and adult cannot be explained by differences in CMRO2.