Serum and urinary biochemistry and enzyme changes in ponies with acute renal failure.

This research article studies the changes in serum and urinary biochemicals in 5 ponies with artificially induced acute tubular nephrosis in an attempt to better understand and diagnose acute renal failure in the early stages. It suggests measurement of urinary gamma glutamyl transferase (GGT) levels as a possible early diagnosis method.

Study Design and Execution

• The research was conducted on 5 ponies. Acute tubular nephrosis, a form of acute kidney injury, was artificially induced in these subjects over 5 days using mercuric chloride and potassium dichromate.
• Several variables were measured daily for 14 days, or until humane euthanasia was performed. These variables included serum osmolality, serum concentrations of urea nitrogen, creatinine, sodium, potassium and chloride, blood pH and blood gases.
• The levels of these same substances were also measured daily in the urine of the subjects.
• Routine urinalysis and determination of urinary gamma glutamyl transferase (GGT) activity was performed for each urine sample.

Findings

• Changes were found in the levels of these chemicals in both serum and urine. The changes in urine levels were noted to precede changes in the same chemicals in the serum by at least one day.
• The earliest abnormality detected was in urinary GGT activities. This change was noted up to 6 days prior to detecting azotemia (excess nitrogen in the blood).

Conclusions

• The research concludes that acute equine renal injury could be diagnosed earliest with biochemical testing of urine, specifically measuring urinary GGT levels.
• It suggests measuring urinary GGT levels as a potential method of diagnosing proximal tubular disease in equidae (horses) in early stages, aiming to improve the odds of recovery or successful treatment.