1. Bioflavonoids attenuate renal proximal tubular cell injury during cold preservation in Euro-Collins and University of Wisconsin solutions 
Thurid Ahlenstiel, Gunther Burkhardt, Hans Köhler, Martin K. Kuhlmann 
Kidney International 
Volume 63, Issue 2, Pages (February 2003)
DOI: /j x
Copyright © 2003 International Society of Nephrology Terms and Conditions

2. Figure 1
Cold-induced injury in LLCPK1 cells. Cells were cold stored at +4°C in the University of Wisconsin (UW; ○, □) or Euro-Collins solution (EC; •, ▪) over a period of 0.5 to 20 hours, followed by 60 minutes of rewarming at 37°C. Cell injury was measured by lactate dehydrogenase (LDH) release (A) and 3-(4,5-dimethylthiazol-2-yl)-2,5-dimethyltetrazolium bromide (MTT) assay (B). Each time point represents mean ± SD of N≥ 30. Differences between the UW and EC solutions were significant at each time point (P < 0.05).
Kidney International  , DOI: ( /j x)
Copyright © 2003 International Society of Nephrology Terms and Conditions

3. Figure 2
Protection from cold-induced injury by various flavonoids using the UW () or EC (▪) solution. Cells were pretreated for 3 hours with 100 μmol/L of various flavonoids (except fisetin with 50 μmol/L) in regular medium 199. Cell damage was assessed by the LDH release (A, B) and MTT-test (C, D) after 20 hours of cold exposure in the UW (A, C) or EC solution (B, D) and 60 minutes of rewarming at 37°C. Flavonoids were absent during cold storage and rewarming. Each bar represents mean ± SD of N≥ 18. *P < 0.01 vs. no flavonoid-pretreatment.
Kidney International  , DOI: ( /j x)
Copyright © 2003 International Society of Nephrology Terms and Conditions

4. Figure 3
Protection from cold-induced injury by luteolin: Concentration kinetics. Cells were preincubated with luteolin at concentrations ranging from 6.25 to 400 μmol/L followed by 20 hours of cold storage in the UW (A) or EC solution (B) and 60 minutes of rewarming in the absence of luteolin. Cell damage was evaluated by LDH release (•, ▪; left ordinate) and MTT-assay (○, □; right ordinate). Each condition represents mean ± SEM of at least N = 12. *P < 0.01 for lowest luteolin concentration vs. no flavonoid pretreatment.
Kidney International  , DOI: ( /j x)
Copyright © 2003 International Society of Nephrology Terms and Conditions

5. Figure 4
Effects of extended rewarming periods on cold-injured, flavonoid-pretreated LLC-PK1 cells. Cells were pretreated for 3 hours with no flavonoid (), quercetin (100 μmol/L; ), kaempferol (100 μmol/L; ), luteolin (100 μmol/L; □) or fisetin (50 μmol/L; ▪) followed by cold preservation in the EC solution. After 20 hours of cold storage preservation solution was replaced by regular medium 199 and cells were rewarmed for 1, 4, or 8 hours at 37°C. Cell damage was assessed by LDH release (A) and MTT-assay (B). Flavonoids were absent during cold storage and rewarming. Each condition represents mean ± SD of at least N = 12. *P < 0.01 vs. cell damage observed after one hour of rewarming for the identical flavonoid-pretreatment.
Kidney International  , DOI: ( /j x)
Copyright © 2003 International Society of Nephrology Terms and Conditions