Fig. 2

Measurement of lactate dehydrogenase (LDH) activity of long-term cultivated rat precision-cut lung slices (PCLS). Viability of tissue PCLS incubated in a standard culture medium (named PCLS in the absence of serum) and others incubated in a culture medium with the addition of 10% fetal bovine serum (FBS) (named PCLS in the presence of serum) was measured using LDH assay (optical density (OD) 492 nm, reference wavelength 595 nm). LDH release (LDHr) over 24 h as well as maximal LDH activity (= total LDH, LDHt) were analysed. Media without slices were used as negative controls, here no LDH activity could be observed. For each timepoint, measurements were performed in duplicates, n = 3. Data is expressed as mean ± standard deviation (SD). Statistics were carried out using the general mixed model analysis (PROC GLIMMIX, SAS 9.4, SAS Institute Inc., Cary, NC, USA), statistical differences to day 1 are indicated by asterisks (*** p < 0.001), statistical differences between the two groups (PCLS in the absence vs. PCLS in the presence of serum) are indicated by hashes (^###p < 0.001)