Influence of anesthesia, postanesthetic state, and restraint on superior mesenteric arterial flow in normal rats

To exclude possible confounding effects of anesthesia on splanchnic hemodynamics, two different awake postanesthetic models (PAM), restrained and unrestrained, have been used. However critical analysis of the splanchnic hemodynamic state in these models is not available. We conducted experiments using chronically implanted pulsed-Doppler flow probes on the superior mesenteric artery (SMA) in ketamine-anesthetized and in postanesthetic restrained and unrestrained normal rats. Baseline values of mean SMA flow were compared with those under anesthesia (30 min), PAM (restrained or unrestrained at 90 and 150 min), and reanesthesia. Sham-anesthetized unrestrained animals provided control values. The same animals (n = 7) underwent the restrained, unrestrained, and control experiments at least 5 days apart. Ketamine anesthesia did not significantly alter mean SMA flow (89 +/- 9% of baseline) compared with sham-anesthetized controls (99 +/- 9%). Mean SMA flow in both PAM, restrained and unrestrained, had a signifi...