Quantitative assessment of hepatic function by means of 99mTc-mebrofenin in healthy horses.

This research article explores the use of 99mTc-mebrofenin to assess liver function in healthy horses, examining the impacts of food withholding and increased serum total bilirubin concentrations on its efficiency. The study suggests that neither fasting nor elevated bilirubin levels affect the drug’s liver extraction efficiency.

Study Methodology

• The study used 7 healthy horses as subjects. They experimented at 0, 48, and 96 hours post-feed withholding.
• The horses were administered 99mTc-mebrofenin through a jugular vein, and blood samples were subsequently taken from the opposite jugular vein.
• They used the blood samples to create a time-activity curve of the 99mTc-mebrofenin in the system.
• The area under the curve (AUC) and the T1/2 of the fast-phase (T1/2f) and slow-phase (T1/2s) were computed from this curve.
• In addition to the 99mTc-mebrofenin measurements, serum total bilirubin (TBIL) and nonesterified fatty acids (NEFA) levels were checked every 24 hours.

Study Findings

• The AUC, T1/2f, and T1/2s measurements remained consistent regardless of the time of feed withholding, suggesting that feeding did not affect the hepatic clearance of 99mTc-mebrofenin.
• There was a significant surge in TBIL concentrations with fasting, with the mean value reaching 6.3 mg/dL at 26 hours.
• NEFA levels also rose, hitting a peak at 48 hours.
• Neither the TBIL nor NEFA values showed a strong correlation with the T1/2s, T1/2f, or AUC values, although TBIL did have a weak correlation with T1/2f.

Conclusion

• The study concludes that 99mTc-mebrofenin plasma clearance is not influenced by food deprivation.
• The hyperbilirubinemia observed with food deprivation does not seem to affect the hepatic extraction efficiency of 99mTc-mebrofenin.
• The findings imply that assessing hepatic function in horses using 99mTc-mebrofenin would provide consistent results, regardless of feeding status or elevated bilirubin levels.