Objective: Portal hypertension is characterized by hyperdynamic splanchnic circulation associated with the development of portosystemic portal collateral circulation. Since blood flow regulation mechanisms in the splanchnic organs can be metabolic, its metabolic capacity has been studied using the mitochondrial enzyme cytochrome C oxidase as histochemical marker.
Method: Cytochrome oxidase was quantified with a histochemical technique in the liver, pancreas and small bowel of Wistar rats in the control group (n = 8) and in rats with portal hypertension by triple stenosing ligation of the portal vein (n = 9) at 28 days of evolution.
Results: All rats with portal hypertension develop portosystemic collateral circulation. In these animals, cytochrome oxidase activity increases (p < 0.01) in the liver (left lateral lobe, periportal zone: 91.81 +/- 5.18 vs. 86.03 +/- 2.82) exocrine pancreas (125.6 +/- 7.25 vs 117.57 +/- 6.43; p < 0.05) as well as in the mucosa (crypts) and duodenum serosa, jejunum and ileum while it decreases in the pericentral zone of the hepatic acinus and intestinal villi.
Conclusion: Cytochrome oxidase is considered an endogenous marker of local tissular metabolic capacity, so that its increased activity in the small bowel mucosa, crypts, exocrine pancreas and visceral peritoneum may be a metabolic factor that induces splanchnic hyperdynamic circulation in short-term portal hypertensive rats.