Local Anesthetic -Bupiv Acaine Increases the Transperitoneal Transport of Solutes. Part II: In Vitro Study

The local anesthetic, bupivacaine, alters the mesothelial permeability to urea and inulin. The effect is biphasic; an initial transient decrease is followed by an increase in permeability of the membrane to both solutes. Cytochalasill B and colchicine can mimic partially the action of bupivacaine, but without the initial decrease in the mesothelilal permeability. Similar to bupivacaine, verapamil also evokes a biphasic effect on the trallsmesothelial nux of urea and inulin. In conclusion bupivacaine induces changes both in trallscellular and intercellular pathways, due to its interaction with calcium ions and the cytoskeleton of the mesothelial cells. Mesothelium is one of the barriers detennining transfer of solutes from blood to the peritoneal cavity during peritoneal dialysis (1). It has been demonstrated that the function of the mesothelial cells may influence the efficiency of the peritoneal dialysis (2–4). Earlier we showed that bupivacaine added to the dialysis fluid in a concentration of 0.25 mmol/l increased the removal of urea and inulin via the peritoneum (5). Our findings suggest that the effect of bupivacaine depended primarily on its action on the mesothelium. We perfonned a series of in vitra experiments on the monolayer mesothelium taken from the ileal rabbit's mesentery in order to define the character of changes induced in this structure by bupivacaine. This paper describes our findings.