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

Abstract

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 significant (P less than 0.05) decrease at 90 min (78 +/- 8 and 83 +/- 12%) and at 150 min (68 +/- 14 and 78 +/- 14%) when compared with baseline and control. Reanesthesia returned SMA flows to baseline values (91 +/- 16%). The variability of mean SMA flow was significantly increased in both PAM. Maximum variability was observed in the restrained model (69 +/- 32%). These results indicate 1) that ketamine anesthesia does not significantly alter SMA flow and 2) that both the restrained and unrestrained PAM exhibit significant alterations of the splanchnic circulation for at least 2 h after complete recovery from anesthesia. Thus, in the absence of critical evaluation, results of splanchnic hemodynamic studies with these models should be questioned.(ABSTRACT TRUNCATED AT 250 WORDS)

Stress-Induced Inhibition of the Hypothalamic-Pituitary-Thyroid Axis Is Attenuated in the Aged Fischer 344/N Male Rat

“…As the metabolic clearance of TSH takes place mainly in the kidney, the decrease observed by others in splanch nic flow during restraint does not seem to affect metabolic clearance of TSH during Immo [28,29].…”

Myofibroblast proliferation, fibrosis, and defective pancreatic repair induced by cyclosporin in rats

“…The latter may be a critical point as pentobarbital and other anaesthetics inactivate or inhibit the action of nitric oxide29 and therefore may reduce splanchnic blood flow 30. Cyclosporin also reduces pancreatic blood flow,31 and consequently the combination of cyclosporin and anaesthetics may well potentiate damage to the gland.…”

The effect of surgical bowel manipulation and anesthesia on intestinal glucose absorption in rats.

“…Surgical bowel manipulation, anesthesia, and restraint decrease the amount of intestinal blood flow and change the distribution of intestinal blood flow (33,34). Intestinal absorption of glucose and other substances are decreased when intestinal blood flow is decreased (9,11,35 (20,44).…”