Tissue pO2 in Isometrically Contracting Skeletal Muscle of Rats with Portacaval Anastomosis (PCA)

In patients suffering from liver cirrhosis alterations of pulmonary microcirculation at rest and exercise have been described (Schomerus et al. 1975, Huber et al. 1980). Measurements of local pO2 in resting skeletal muscle of patients with liver disease indicate that microcirculation of peripheral organs is also influenced by liver cirrhosis (Fleckenstein et al. 1984 a,b). Portacaval end-to-side anastomosis (PCA) in rats leads to similar changes of systemic circulation as described in patients with liver cirrhosis: “hyperdynamic cardiovascular state” including increased cardiac output, decreased peripheral vascular tone, increased pulmonary venous admixture and elevated mean systolic ejection rate (Liehr et al. 1976). We used this well defined experimental model to investigate the effect of hypercirculation on microcirculation and tissue oxygenation in peripheral organs. In former studies we found the establishment of PCA in rats with intact liver function to result in a marked increase of mean muscular pO2 at rest. Furthermore we reported data that late after PCA regulation of muscle tissue oxygenation is altered under conditions of hyperoxia (Heinrich et al. 1984/1985 a). In order to get more information about tissue oxygenation during hypercirculation we studied the influence of increased oxygen demand (work) on mean muscular pO2 in rats with PCA.