Determination of aminoglycosides in rat renal tissue by enzyme immunoassay.

The enzyme-multiplied immunoassay technique for the determination of gentamicin or amikacin in serum was evaluated for use in rat renal tissue. After the addition of either gentamicin or amikacin to tissue homogenate, the assay of the supernatant showed a reduced recovery, depending on the amount of renal tissue present per milliliter of homogenate. The recovery was independent of the amount of aminoglycoside added. This reduction could be due to either protein binding or interference with the enzyme-multiplied immunoassay technique by substances released from the renal tissue. When the enzyme-multiplied immunoassay technique is used for aminoglycoside assay in renal tissue, care should be taken to minimize the amount of tissue present in the homogenate or to correct for the decreased recovery.