Abstract: TH-PO0243
Renal Reserve Assessment by Transdermal Fluorescence Detection: An In Vivo Porcine Model
Session Information
- CKD: Mechanisms of Injury and Fibrosis - 1
October 22, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: CKD (Non-Dialysis)
- 2203 CKD (Non-Dialysis): Mechanisms
Authors
- Dorshow, Richard B., MediBeacon Inc, St. Louis, Missouri, United States
- Debreczeny, Martin, MediBeacon Inc, St. Louis, Missouri, United States
- Johnson, James R., MediBeacon Inc, St. Louis, Missouri, United States
- Riley, I. Rochelle, MediBeacon Inc, St. Louis, Missouri, United States
- Talcott, Michael R., Washington University in St Louis, St. Louis, Missouri, United States
Background
Renal reserve is the peak GFR measured occurring after a specific stimulus. The most widely used stimulus is a high protein load, either given orally or intravenously as an amino acid. Measurement procedures usually encompass invasive and time-consuming blood draws to ascertain endogenous or exogenous agent concentration for GFR determination. We have recently shown relmapirazin to be an exogenous fluorescent GFR tracer agent, and its transdermal fluorescence detection yielded a point-of-care assessment of GFR. We hypothesize that this methodology is suitable for use in determination of renal reserve status and have investigated an in vivo porcine model to demonstrate feasibility.
Methods
A transdermal fluorescence detection system, with the light source-photodetector module placed on the abdomen of the anesthetized animals, acquired fluorescence data over a six hour period. A saline bolus fluid administration was given to one pair of animals partway through this monitoring interval. An amino acid bolus fluid administration was given to a second pair of animals partway through the monitoring interval.
Results
A single compartment fit to the post bolus fluorescence vs. time data yielded a steeper slope for the amino acid bolus with respect to the saline bolus indicating a higher GFR (Figure 1). The time constant from these fits showed a 32% reduction of the amino acid bolus compared to the saline bolus (Table 1).
Conclusion
The noninvasive transdermal fluorescence detection methodology demonstrated feasibility in determining renal reserve in this porcine model.
Comparison of average time constants, rate constant, and GFR (for n=2 animals) post fluid administration
| Bolus | Avg. Time Constant (hours) | Rate Constant (hours)-1 | GFR (ml/min/1.73m2)* |
| Saline | 1.95 | 0.51 | 114 |
| Amino acid | 1.32 | 0.76 | 169 |
*Using the human rate constant to GFR conversion algorithm
Single compartment fits to post saline bolus data (blue lines) and post amino acid bolus (red lines). Solid and dash lines each represent one animal.
Funding
- Commercial Support – MediBeacon Inc.