Hamaji M, Nakaba H, Nakamura M, Izukura M, Miyata M, Kawashima Y
J Surg Res. 1987 Sep;43(3):234-8. doi: 10.1016/0022-4804(87)90076-x.
We studied the influence of an adreno-femoral venous shunt on the regional blood flow in the dog adrenal gland during hemorrhagic hypotension. An adreno-femoral venous shunt was placed transperitoneally in the left adrenal gland while the animal was under pentobarbital anesthesia. The right adrenal gland was left intact. Hemorrhagic hypotension was induced at 50 mm Hg mean arterial blood pressure for 1 hr in six dogs and the other six dogs served as normotensive controls. Nonradioactive microspheres (2 X 10(6), 15 +/- 2 micron) were injected into the ventricle. The adrenal cortical and medullary blood flows were estimated by microscopic counting of the microspheres in the serially sectioned adrenal gland. The total adrenal blood flow (sum of the cortical and medullary blood flows) of two methods was compared; the microsphere method vs timed venous sampling through the shunt. In the intact right adrenal gland, the cortical blood flow was significantly decreased, but the medullary blood flow remained unchanged during hemorrhagic hypotension. Subsequently the total adrenal blood flow was not significantly decreased. In the cannulated left adrenal gland, both the cortical and medullary blood flows were significantly decreased and adrenal vascular autoregulation was inhibited. The total adrenal blood flow calculated by the microsphere method showed a significant correlation with that by timed venous sampling through the shunt. These results indicate that the adrenal medullary vasculature autoregulates during hemorrhagic hypotension and that an adreno-femoral venous shunt abolishes this vascular response.
我们研究了肾上腺-股静脉分流术对失血性低血压期间犬肾上腺局部血流的影响。在戊巴比妥麻醉下，经腹膜在左肾上腺放置肾上腺-股静脉分流管。右肾上腺保持完整。6只犬诱导平均动脉血压为50 mmHg的失血性低血压1小时，另外6只犬作为正常血压对照。将非放射性微球（2×10⁶，15±2微米）注入心室。通过对肾上腺连续切片中微球的显微镜计数来估计肾上腺皮质和髓质血流。比较了两种方法的总肾上腺血流（皮质和髓质血流之和）；微球法与通过分流管的定时静脉采样法。在完整的右肾上腺中，失血性低血压期间皮质血流显著减少，但髓质血流保持不变。随后总肾上腺血流未显著减少。在插有分流管的左肾上腺中，皮质和髓质血流均显著减少，肾上腺血管自身调节受到抑制。通过微球法计算的总肾上腺血流与通过分流管的定时静脉采样法计算的结果显示出显著相关性。这些结果表明，失血性低血压期间肾上腺髓质血管系统存在自身调节，且肾上腺-股静脉分流术消除了这种血管反应。
