喂养对新生犊牛脑血流量和氧消耗的影响。

The effect of feeding on cerebral blood flow and oxygen consumption in the new-born calf.

作者信息

Gardiner R M

出版信息

J Physiol. 1980 Apr;301:429-38. doi: 10.1113/jphysiol.1980.sp013215.

DOI:10.1113/jphysiol.1980.sp013215

PMID:6774083

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1279408/

Abstract

The effect of feeding on cerebral blood flow and oxygen consumption has been investigated in unrestrained calves between 7 and 28 days after birth.2. Cerebral blood flow was determined using an inert gas clearance technique, and oxygen consumption by the simultaneous measurement of the arterio-cerebral venous oxygen content difference.3. Cerebral blood flow increased during feeding from 74 +/- 4 to 116 +/- 9 ml. 100 g(-1) min(-1) and reverted afterwards to the pre-feed level. No alteration in cerebral oxygen consumption occurred.4. Feeding was associated with an increase in mean arterial blood pressure and heart rate, and mild asphyxia.5. The sensitivity of the cerebral circulation to alterations in arterial P(CO2) was investigated in seven calves under sodium pentobarbitone anaesthesia. In the range of arterial P(CO2) 15-75 mm Hg the relationship was linear (r = 0.71; P < 0.001) with an average slope of 0.68 ml. 100 g(-1) min(-1) mmHg P(a,CO2) (-1).6. Increases in mean arterial blood pressure comparable to those occurring during feeding (96 +/- 6 to 159 +/- 8 mmHg) were produced by compression of the thoracic aorta in three calves under sodium pentobarbitone anaesthesia and were associated with an increase in cerebral blood flow from 48 +/- 4 to 76 +/- 8 ml. 100 g(-1) min(-1). No significant change in calculated cerebral vascular resistance occurred during either feeding or aortic compression.7. These results suggest that the rise in blood pressure which occurs during feeding in the calf exceeds the autoregulatory capacity of the cerebral circulation.

摘要

对出生7至28天的未束缚小牛进食对脑血流量和氧消耗的影响进行了研究。
使用惰性气体清除技术测定脑血流量，通过同时测量动脉 - 脑静脉氧含量差来测定氧消耗。
进食期间脑血流量从74±4增加到116±9 ml·100 g⁻¹·min⁻¹，之后恢复到进食前水平。脑氧消耗无变化。
进食与平均动脉血压和心率增加以及轻度窒息有关。
在七只戊巴比妥钠麻醉的小牛中研究了脑循环对动脉P(CO₂)变化的敏感性。在动脉P(CO₂)为15 - 75 mmHg范围内，关系呈线性（r = 0.71；P < 0.001），平均斜率为0.68 ml·100 g⁻¹·min⁻¹·mmHg P(a,CO₂)⁻¹。
在三只戊巴比妥钠麻醉的小牛中，通过压迫胸主动脉产生了与进食期间相当的平均动脉血压升高（从96±6到159±8 mmHg），并伴有脑血流量从48±4增加到76±8 ml·100 g⁻¹·min⁻¹。进食或主动脉压迫期间计算的脑血管阻力均无显著变化。
这些结果表明，小牛进食期间出现的血压升高超过了脑循环的自动调节能力。