Volume 60, Issue 6, Pages 2367-2376 (December 2001) Effects of uremic serum on isolated cardiac myocyte calcium cycling and contractile function.  Sankaridrug M. Periyasamy, Jie Chen, Derek Cooney, Patricia Carter, Eiad Omran, Jiang Tian, Snigdha Priyadarshi, Alexei Bagrov, Olga Fedorova, Deepak Malhotra, Zijian Xie, Joseph I. Shapiro, M.D.  Kidney International  Volume 60, Issue 6, Pages 2367-2376 (December 2001) DOI: 10.1046/j.1523-1755.2001.00053.x Copyright © 2001 International Society of Nephrology Terms and Conditions

Figure 1 Relationship between amount of serum and inhibition of purified NaK-ATPase activity. Symbols are: (●) control patients; (▼) uremic patients. **P < 0.01 vs. control. Kidney International 2001 60, 2367-2376DOI: (10.1046/j.1523-1755.2001.00053.x) Copyright © 2001 International Society of Nephrology Terms and Conditions

Figure 2 Relationships between the concentration of ouabain (A) and uremic serum extract (B) and inhibition of 86Rb uptake in LLCPK-1 (●) and NRK (▼) cells. Kidney International 2001 60, 2367-2376DOI: (10.1046/j.1523-1755.2001.00053.x) Copyright © 2001 International Society of Nephrology Terms and Conditions

Figure 3 Representative responses of cellular contraction and Indo-1 fluorescence to addition of uremic extract 1.5%. Effects of calibration with ionomycin and EGTA also are shown. Kidney International 2001 60, 2367-2376DOI: (10.1046/j.1523-1755.2001.00053.x) Copyright © 2001 International Society of Nephrology Terms and Conditions

Figure 4 Representative cell length (A) and cytosolic calcium (B) measurements obtained from cardiac myocytes exposed to deproteinized normal and uremic serum extracts (3.75%) during field stimulation at 0.5Hz. Kidney International 2001 60, 2367-2376DOI: (10.1046/j.1523-1755.2001.00053.x) Copyright © 2001 International Society of Nephrology Terms and Conditions

Figure 5 Effect of Fab fragment directed against digitalis (D) on the uremic extract pooled from 4 of the 5 patients (UE, 10%) inhibition of 86Rb uptake in LLCPK-1 cells. Each data point was derived from N = 3 experiments. D is Fab fragment alone (10, 20 and 40 μL data pooled). Final reaction volume was approximately 1mL. *P < 0.05 and **P < 0.01 vs. UE alone. D alone not compared with UE alone. Kidney International 2001 60, 2367-2376DOI: (10.1046/j.1523-1755.2001.00053.x) Copyright © 2001 International Society of Nephrology Terms and Conditions

Figure 6 Effect of Fab fragment (D) on uremic extract (UE 3.5%) effects on myocyte contraction, relaxation and calcium cycling. Data are presented as percent change from baseline after 5 minutes following addition of UE alone or UE mixed with D. Each data point was obtained from N = 4 replicants. Symbols are: (□) fractional shortening; () diastolic [Ca]; () systolic [Ca]; () τ edge; () τ calcium. *P < 0.05 and **P < 0.01 vs UE alone. Kidney International 2001 60, 2367-2376DOI: (10.1046/j.1523-1755.2001.00053.x) Copyright © 2001 International Society of Nephrology Terms and Conditions