COMPARATIVE RENAL DISPOSITION OF CREATINE, AND TECHNETIUM DIAGNOSTIC CONTRAST AGENTS IN THE PIGEON (COLUMBA LIVIA)

Area of Science:

• Veterinary Medicine
• Renal Physiology
• Nuclear Medicine

Background:

• Assessing avian renal function is challenging due to insensitive markers like uric acid and BUN.
• Mammalian creatinine is a key marker, but avian species primarily produce creatine.
• A need exists for more accurate methods to evaluate kidney function in birds.

Purpose of the Study:

• To characterize renal clearances of 99mTc-DTPA and 99mTc-MAG3 in pigeons.
• To compare the elimination kinetics of DTPA, MAG3, and creatine.
• To establish novel radiotracer methods for avian renal function assessment.

Main Methods:

• Pigeons were infused with 99mTc-DTPA and inulin to assess glomerular filtration.
• 99mTc-MAG3 and creatine were administered to evaluate filtration and excretion/resorption.
• Blood disappearance curves were analyzed to determine clearance rates and patterns.

Main Results:

• DTPA clearance paralleled inulin, confirming glomerular filtration.
• MAG3 exhibited significantly faster clearance than DTPA, indicating active tubular excretion.
• Creatine showed complex elimination, suggesting filtration with resorption or other factors.

Conclusions:

• 99mTc-DTPA and 99mTc-MAG3 are suitable radiotracers for avian renal function evaluation.
• DTPA reflects glomerular filtration, while MAG3 indicates filtration and active secretion.
• Creatine's complex elimination requires further investigation for its use as a renal marker.