Sequential multi-organ preparation of rat liver and kidney precision-cut tissue slices: impact of collection method, anatomical region, and processing time on ATP-based viability

Precision-cut tissue slices (PCTS), defined as thin, uniformly cut sections of fresh organs that preserve native tissue architecture and cell-cell interactions, serve as valuable ex vivo models for studying tissue physiology, toxicology, and metabolism of drug substances. However, existing PCTS preparation protocols typically focus on single-organ preparation, leaving the feasibility of sequential multi-organ slicing remains uncertain. This study evaluated the viability of rat liver and kidney slices during a 72-hour incubation period, considering factors such as sex, organ collection method, coring technique, and slicing duration. Viability was assessed based on intracellular Adenosine Triphosphate (ATP) as an indicator of metabolic activity. No sex-related differences in ATP levels were observed in 18-20-month-old rats. ATP content was also comparable between central and peripheral liver regions. In contrast, kidney slices composed of the medulla demonstrated significantly higher ATP levels than those predominantly composed of cortex, reflecting regional differences in microanatomy and metabolic adaptability. Furthermore, slices obtained from anesthetized rats showed better ATP recovery during incubation than those from euthanized rats, highlighting the importance of adequate oxygen supply maintained through blood circulation during organ collection. The sequential preparation of liver and kidney slices within 4 hours after organ collection was feasible, as slicing performed within 0-2 hours and 2-4 hours did not significantly affect viability. These findings provide practical insights for optimizing PCTS preparation supporting reliable slice viability, and enabling efficient multi-organ processing when tissue slicer capacity is limited.