<Original Articles>Suppression of Hepatic Portal Blood Flow Caused by Carbon Dioxide Pneumoperitoneum Can Be Restored After Dopamine Administration in Pigs

Abstract

Portal venous blood flow (PVF), hepatic arterial blood flow (HAF) and systemic arterial pressure (SAP) were examined after dopamine (DA) injection into the jugular vein under carbon dioxide pneumoperitoneum in pigs. When intraabdominal pressure (IAP) was increased by 12 mmHg, PVF and HAF were reduced, but SAP was unchanged. When IAP was kept at 12 mmHg, the injection of DA at 10 μg/kg/min for 2 min produced an increase in PVF without causing any change in HAF or SAP. The response in PVF was dose-dependent. When IAP was increased to 16 mmHg, PVF response was diminished, and no change in HAF or SAP was seen at the same dose of DA. These observations suggest that DA is effective in increasing PVF under enhanced IAP conditions, but such circulatory improvement due to the agent would be prominent when IAP is below 12 mmHg.

豚を用いて二酸化炭素気腹下でドパミンの頸静脈投与が門脈血流量, 肝動脈血流量, 体血圧に対する影響を調へた腹腔内圧を 12 mmHg まで高めると, 門脈と肝動脈血流量は減少したが, 体血圧には変化を認めなかった. 腹腔内圧を 12 mmHg で維持した状態で, ドパミン 10 μg/kg/min で2分間の投与は肝動脈血流量と体血圧に変化を与えることなく, 門脈血流量を増加させた. こうしたドパミンによる門脈血流量反応は用量依存性を示した. 腹腔内圧 16 mmHg では同用量のドパミンの投与で, 門脈血流量反応は低下したが, 肝動脈血流量と体血圧には変化を認めなかった. これらの観察から, ドパミンは腹腔内圧上昇時に肝門脈血流量を増加させること, しかしそうしたドパミンの肝循環改善効果は腹腔内圧 12 mmHg 以下で顕著であることを導いた.