LAPAROTOMY AND RENAL-FUNCTION DURING ENDOTOXIN-SHOCK IN RATS

Despite the wide use of laparotomy to study kidney function, the possi ble influence of this procedure on systemic and renal parameters in se ptic rats is unknown, We studied this in anesthetized Wistar rats with and without endotoxin shock (1 h Escherichia coil O127.B8: 8 mg . kg( -1) infusion). We also compared clearance of creatinine and inulin to measure glomerular filtration rate (GFR). Laparotomy attenuated the en dotoxin-induced decrease in cardiac output and abolished the increase in systemic and renal vascular resistance, while renal plasma flow was maintained. Better perfusion in other organs as well was indicated by a more gradual increase in arterial lactate concentration and less in testinal damage. By contrast, GFR decreased considerably during endoto xemia, irrespective of laparotomy. This change in GFR could be reliabl y assessed using creatinine clearance. The ratio of creatinine-to-inul in clearance averaged between .5 and .75. Renal ATP content did not ch ange and the endotoxin-induced increase in the number of granulocytes lodged in glomeruli was not affected by laparotomy. in conclusion, our study indicates that laparotomy significantly influences the vascular effects caused by endotoxin. Laparotomy also revealed an effect of en dotoxin on GFR, independent of renal blood flow.