A method for determining urinary enzyme activities as nephrotoxic indicators in rats

Area of Science:

• Biochemistry
• Toxicology
• Pharmacology

Background:

• Drug-induced nephrotoxicity is a significant concern in preclinical studies.
• Accurate and sensitive detection methods are crucial for assessing kidney damage.
• Existing methods for evaluating drug nephrotoxicity can be time-consuming or complex.

Purpose of the Study:

• To develop a simple and useful method for detecting drug nephrotoxicity in rats.
• To evaluate the efficacy of the developed method using various nephrotoxic agents.

Main Methods:

• Collected rat urine stimulated from the sacral region.
• Partially purified urinary enzymes using centrifugal ultrafiltration (Amicon MPS-1 kit).
• Measured activities of N-acetyl-beta-D-glucosaminidase (NAG), alanine aminopeptidase (AAP), gamma-glutamyltranspeptidase (gamma GTP), lactate dehydrogenase (LDH), and protein concentration, expressed as creatinine ratios.

Main Results:

• Observed marked increases in enzyme activities and protein concentration in rats treated with nephrotoxic drugs (cephaloridine, HgCl2, cisplatin, gentamicin).
• Different drug treatments showed distinct patterns of enzyme activity increase.
• Lactate dehydrogenase (LDH) exhibited the highest response, while N-acetyl-beta-D-glucosaminidase (NAG) showed the longest-lasting effect.
• Results correlated with previous studies using dialyzed 24-hour urine.

Conclusions:

• The developed method is efficient for detecting drug nephrotoxicity in rats.
• This method provides a sensitive and practical approach for preclinical kidney safety assessment.
• Urinary enzyme profiling can differentiate the nephrotoxic effects of various drugs.