A focus of tissue necrosis increases renal susceptibility to gentamicin administration.

The purpose of this study was to determine whether a retained focus of necrotic tissue predisposes to aminoglycoside-induced acute renal failure (ARF). Rats were subjected to either (1) 25% liver ligation, creating a focus of ischemic tissue which was left in place; (2) 25% liver resection; or (3) sham liver ligation. Gentamicin, 80 mg/kg bid, was administered for two days after surgery to all three groups. A fourth group was subjected to 25% liver ligation but no gentamicin therapy. Only rats subjected to partial liver ligation plus gentamicin treatment developed ARF, manifested by azotemia (BUN 80 +/- 2; creatinine 1.63 +/- 0.21; mg/dl) and tubular necrosis. This occurred in the absence of any discernible reduction in arterial blood pressure, renal blood flow, excessive weight loss, or ascites formation. The partial liver ligation-gentamicin group had 70% higher renal gentamicin concentrations than the liver resection-gentamicin controls (P = 0.01). To assess whether factors released from necrotic liver might account for these findings, additional rats were infused with: (1) 1 ml of a soluble liver extract alone; (2) 1 ml of liver extract plus gentamicin; or (3) 1 ml of saline plus gentamicin. Only the liver extract/gentamicin group developed ARF (BUN 88 +/- 13; creatinine 1.46 +/- 0.25). This occurred in association with a 110% increase in renal gentamicin uptake (P less than 0.03). In separate experiments, 5 ml liver extract infusions caused ARF (BUN 118 +/- 7; creatinine 2.1 +/- 0.18) without gentamicin treatment. In conclusion, a focus of liver necrosis can predispose to experimental gentamicin nephrotoxicity.(ABSTRACT TRUNCATED AT 250 WORDS)