Figure legends
Figure 1. Mean lumen diameter (A), contractile response to 32 mM K+ (B), relaxing response to 1 μM bradykinin (C) and the relation of the K+-induced contraction to the lumen diameter (D) in the pericardial resistance arteries investigated. Data are shown as mean of the observations in 3 – 6 arterial segments from the same patient (dots) and as median and interquartile range of the entire study group.
Figure 2. Relaxing responses to bradykinin (BK) during contraction stimulated by K+ or endothelin-1 (ET-1) in preparations without (+Endo) and with (-Endo) prior gentle mechanical damage of their luminal surface. Mean observations (A) along with typical tracings of tension as a function of time illustrating effects of BK during contraction stimulated with K+ (B) or ET-1 (C) in arterial segments from the same patient.
Figure 3. Immunohistochemical (IHC) staining for detection of NO-synthases and antioxidant enzymes in patient pericardial resistance arteries illustrated by typical examples and results of semi-quantitative analyses summarized by violin plots (N = 28). A and B, endothelial NO-synthase (eNOS) in a pericardial resistance artery and an atrial appendage, respectively. C, inducible NO-synthase (iNOS), D, neuronal NO-synthase (nNOS), E, catalase (CAT) and F, superoxide dismutase 1 (SOD1) in pericardial resistance arteries. EC, endothelium; SMC, medial smooth muscle; ADV, tunica adventitia. Scale bar 50 μm.
Figure 4. Effects of inhibition of prostanoid, oxidative and nitrosative processes on endothelium-independent SNP-induced relaxations in K+-precontracted pericardial arteries. A and B, relaxing responses to 1 µM SNP in the absence and presence of 100 µM L-NAME, 300 µM c-PTIO and 10 µM ODQ in the absence (A) and presence of 10 µM indomethacin (INDO, B). C and D, cumulative-concentration response curves to SNP (C) and CXL-1020 (D) in the absence and presence of 3 mM NAC, 3 mM DETCA and 50 mM Amitrole. Data are shown as means ± SEM; n = 6-12. *, significantly different from control after comparison by one-way mixed-effects ANOVA corrected for multiple comparisons by Dunett’s post-hoc test.
Figure 5. Effects of 2000 U/ml catalase (CAT) and 100 µM L-NAME on relaxing responses to H2O2 in pericardial arteries made to contract with 32 mM K+(A) or an equieffective concentration of ET-1 (B). Data are shown as means ± SEM; n = 5-9. *, significantly different from control after comparison by one-way mixed-effects ANOVA corrected for multiple comparisons by Dunett’s post-hoc test.
Figure 6. Effects of inhibition and scavenging of cyclooxygenase, nitrosative and oxidative pathways on contractile responses to 32 mM K+ in pericardial resistance arteries. A, effect of 300 µM c-PTIO, 100 µM L-NAME and 10 µM ODQ in the absence (circles) and presence (rhombuses) of 10 µM indomethacin (INDO). B, effect of 3 mM NAC, 3 mM DETCA and 50 mM amitrole; C, 2000 U/ml CAT, 2000 U/ml CAT + 100 µM L-NAME and 100 µM L-NAME; and D, 100 µM 7-NI, 3 µM NPLA and 100 µM L-NAME on the contractile response in segments from the same arteries, respectively. Data are shown as mean ± SEM; N = 6-15.* , P < 0.05 significantly different from control; #, P < 0.05 compared to Control + INDO. Statistical significance of differences was assessed by one-way mixed-effects ANOVA corrected for multiple comparisons by Dunett’s post-hoc test.
Figure 7. Effects of inhibition of cyclooxygenase, nitrosative and oxidative processes on BK-induced relaxations in pericardial resistance arteries precontracted with 32 mM K+. A and B, relaxing responses to 1 µM BK in the absence and presence of 100 µM L-NAME, 300 µM c-PTIO and 10 µM ODQ in the absence (A, circles) and presence of 10 µM indomethacin (INDO) (B, rhombuses). C and D, cumulative-concentration response curves to BK in the absence and presence of 3 mM NAC, 3 mM DETCA and 50 mM Amitrole (C) or 2000 U/ml CAT, 2000 U/ml CAT + 100 µM L-NAME and L-NAME alone. Data are shown as means ± SEM; N = 6-14. * , P < 0.05 versus control (one-way mixed-effects ANOVA corrected for multiple comparisons by Dunett’s post-hoc test).
Figure 8. Effects of non-selective NOS inhibition and nNOS-selective inhibition on BK-induced endothelium-dependent relaxation in pericardial resistance arteries. Cumulative concentration response curves summarizing relaxing effects of BK in K+- (A) and ET-1- (B) pre-contracted arteries in the absence and presence of 100 µM 7-NI, 3 µM NPLA or 100 µM L-NAME. Data are shown as means ± SEM; n = 5-11. *, P < 0.05 versus control (one-way mixed-effects ANOVA corrected for multiple comparisons by Dunett’s post-hoc test).
Figure 9. Effects of inhibition of cyclooxygenase, nitrosative and oxidative processes on BK-induced relaxations in pericardial resistance arteries precontracted with ET-1. A and B, relaxing responses to 1 µM BK in the absence and presence of 100 µM L-NAME, 300 µM c-PTIO and 10 µM ODQ in the absence (A, circles) and presence of 10 µM indomethacin (INDO) (B, rhombuses). C and D, cumulative-concentration response curves to BK in the absence and presence of 3 mM NAC, 3 mM DETCA and 50 mM Amitrole (C) or 2000 U/ml CAT, 2000 U/ml CAT + 100 µM L-NAME and L-NAME alone. Data are shown as means ± SEM; N = 6-12. * , P < 0.05 versus control (one-way mixed-effects ANOVA corrected for multiple comparisons by Dunett’s post-hoc test). These results were obtained after the same arterial segments were investigated for BK-induced relaxation during K+-induced contraction (Figure 7).
Figure 10. Comparison between arteries from patients that required coronary bypass grafting (CABG, left) or valve replacement surgery (VRS, right). The individual data illustrate the effect of 100 µM L-NAME on the relaxing response to 1 µM BK in the same arterial segments made to contract with 32 mM K+ or ET-1.
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