Prostacyclin mediation of vasodilation following mesenteric traction.

Eight untreated patients (group I) and four patients who received ibuprofen preoperatively (group II) scheduled for elective abdominal aortic aneurysm repair were studied. Heart rate (HR); systolic, diastolic, and mean arterial pressure (MAP); systolic and diastolic pulmonary artery pressure; pulmonary capillary wedge pressure (PCWP); cardiac output (CO); and central venous pressure (CVP) were recorded pre-induction, before mesenteric traction, and 5, 15, and 30 min post-mesenteric traction. Plasma samples were obtained at these times for analysis of six-keto-prostaglandin F1 alpha (PGF1 alpha) concentration by radioimmunoassay. Group II patients received ibuprofen 12 mg/kg orally 1 1/2 h before surgery. Plasma samples from six group I patients and all group II patients taken 5 min after mesenteric traction were added to isolated helical strips of cat superior mesenteric arteries precontracted with norepinephrine (200 ng/ml) for analysis of reduction in developed force. In group I, abdominal mesenteric traction resulted in a significant decrease in MAP (P less than 0.03) and SVR (P less than 0.005) with an increase in CO (P less than 0.05) at 5 min post-mesenteric traction, which returned to mean pre-mesenteric traction values by 30 min and a significant increase in PGF1 alpha concentrations. There was a significant positive correlation between PGF1 alpha and CO (P less than 0.001) and a significant negative correlation between PGF1 alpha and SVR (P less than 0.01) at 5 min post-mesenteric traction.(ABSTRACT TRUNCATED AT 250 WORDS)