Characterization of human precision cut liver slices by various viability andfunctional parameters during 24 hour culture

Precision-cut liver slices (PCLiS) represent a valuable ex vivo model as they maintain the original structure and cellular composition of the liver. Since, PCLiS preserve almost all vital liver functions they can be helpful to investigate various scientific questions in the fields of pharmacology and toxicology. To estimate the extent of inter-donor variation, we conducted an extensive characterization of human PCLiS including nine readouts, which covered viability (ATP content, LDH-,AST-,GLDHleakage) functionality (urea production), and histological and descriptive parameters (protein content, wet weight, slice thickness). Liver slices (Ø 8 mm, ~ 280 µm thickness) from healthy tissue of five patients, undergoing partial hepatectomy, were prepared and cultured in a dynamic culture system under carbogen (95% O2, 5% CO2) gassing for 24h. The quality of the hPCLiS was assessed for freshly prepared slices, after the pe-incubation (PI) of 1h and after 24 h post PI. In particular the ATP content varied greatly between the different donors. Moreover the histomorphological evaluation of the tissue revealed certain distinctions concerning the steatosis degree and the present glycogen storage. However, the general histology of the slices reflected the normal liver structure, and the hepatocytes were characterized by their typical polygonal shape. Despite these differences the slices showed a similar behaviour during the culture period. The ATP and protein content were decreased by about 40% during the 24h culture period, whereas urea production showed an overall reduction of 85 %. Enzyme leakage after 24 h ranged from 35 to 40 % and the slice thickness remained largely unchanged. In conclusion, human PCLiS represent a promising liver model when high quality liver tissue is used and the slices are cultured under optimal conditions