A study of systemic blood flow in the fetus with cardiac failure using a sheep fetus model

羊胎儿模型对心力衰竭胎儿全身血流的研究

• 批准号: 02670729
• 负责人: OKAMURA Kunihiro
• 金额: $ 1.41万
• 依托单位: Tohoku Univerisity
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02670729/

There are two main factors, neurological and serological, involved iii circulatory control in the fetus. These factors play an important role in redistribution of blood flow, increasing blood flow to the vital organs such as brain, heart and adrenal gland, when the fetus fell in distress. This study clarified that not only cardiac but peripheral regulation should maintain fetal circulation.Canulation to fetal femoral artery and vein was performed in the sheep fetus in 120-135 gestational days. Transit-time ultrasonic flow meters were placed around ascending aorta and pulmonary artery and then a pacing lead wire was attached with some stitches at the ventricle. Atrio-vetricular block was completed by the injection of 10% formalin solution at intraventricula septum. Artificial A-V block decreased fetal heart rate from 168 to 81 bpm and, -cardiac outpu-L, to 40 % of normal condition. Returning -fetal heart rate at 180 bpm by pacing and the decreasing it stepwise, stroke volume increased up to the period of 100 bpm heart rate. When the heart rate was stepwise decreased by pacing, fetal arterial pressure fluctuated with a characteristic wave in a 20-30 second cycle. This waving pattern of arterial pressure disappeared soon, but reappeared when the heart rate was changed down further. This pattern was not affected by parasympathetic or sympathetic blockades.In conclusion, fetus has own not only cardiac but peripheral vascular regulation to maintain circulation.

有两个主要因素，神经和血清学，涉及胎儿的循环控制。这些因素在血流重新分配中起着重要作用，当胎儿陷入困境时，增加血液流向重要器官，如大脑，心脏和肾上腺。本研究阐明了维持胎儿血液循环的不仅是心脏，而且是外周调节。在升主动脉和肺动脉周围放置超声心动图，然后在心室缝合起搏导线。室间隔注射10%福尔马林溶液完成房室阻滞。人工房室阻滞使胎心率从168次/分降至81次/分，心输出量降至正常情况的40%。通过起搏将胎心率恢复至180 bpm并逐步降低，每搏输出量增加至100 bpm心率。当起搏器逐渐降低心率时，胎儿动脉压在20-30秒周期内呈特征性波动。这种动脉压波动模式很快消失，但当心率进一步降低时又重新出现。这种模式不受副交感神经或交感神经阻滞的影响。总之，胎儿不仅有自己的心脏，但外周血管调节，以维持循环。