Protein expression levels of the ventricular α-1 Na⁺, K⁺-ATPase subunit.

<p>Bands that are representative of the Western blots of the expression of α-1 Na⁺, K⁺-ATPase subunit and GAPDH (Glyceraldehyde 3-phosphate dehydrogenase) are presented at the top of the figure. Results are expressed as the ratio between the area and density of α-1 Na⁺, K⁺-ATPase subunit and GAPDH in the control (Ct) and lead treated (Pb) groups. Number of animals = 7 for each group. <i>p</i>>0.05, Ct vs Pb, Student t<i>-</i>test.</p

Concentration-response curve for increasing extracellular [Ca⁺⁺] in isolated left ventricular papillary muscles from control and lead-treated rats.

<p>Symbols represent mean ± SEM. Open circles- controls (N = 9), filled squares- lead treated group (N = 10). *<i>p</i><0.05, Ct-group <i>vs.</i> Pb-group, two-way repeated measures ANOVA, followed by Bonferroni’s test.</p

Peak and plateau of the isometric force in isolated left ventricular papillary after tetanic stimulation in the absence and presence of verapamil (Ver) of control (Ct), lead treated (Pb), control+verapamil (Ct Ver), lead treatred+verapamil (Pb Ver).

<p>Each column represents the means ± SEM. Number of animals = 6 for each group. *<i>p</i><0.05, Pb <i>vs.</i> control, one-way ANOVA, followed by Tukey’s test.</p

Effects of lead exposure on haemodynamic arterial and ventricular parameters in anaesthetised rats.

<p>Systolic Arterial Pressure (SAP); Diastolic Arterial Pressure (DAP); Mean Arterial Pressure (MAP); Left Ventricular Systolic Pressure (LVSP); End Left Ventricular Diastolic Pressure (LVDP); Right Ventricular Systolic Pressure (RVSP); End Right Ventricular Diastolic Pressure (RVDP); Left Ventricular Positive (dP/dt+LV) and Negative (dP/dt – LV) Derivates; Right Ventricular Positive (dP/dt+RV) and Negative (dP/dt – RV) Derivates; and Heart Rate (HR). Means ± SEM. Animal number range = 9–12.</p><p>*<i>p</i><0.05, as assessed using Unpaired Student’s t-test.</p

Protein expression levels of the ventricular calcium pump SR (SERCA 2), phospholamban (PLB), phospho-Tre¹⁷-PLB, phospho-Ser¹⁶-PLB, as well as the ratios phospho-Tre¹⁷-PLB/PLB and phospho-Ser¹⁶-PLB/PLB from controls (Ct) and lead treated (Pb) groups.

<p>Bands are representative of the Western blots of the expression of SERCA-2, PLB, phospho-Tre¹⁷-PLB, phospho-Ser¹⁶-PLB and GAPDH (Glyceraldehyde 3-phosphate dehydrogenase) are presented at the top of the figure. The results are expressed as the ratio between the area and density of SERCA-2 or PLB and GAPDH in the Ct- and Pb-groups. Number of animals = 7 for each group.*<i>p</i><0.05, Ct vs Pb, Student t<i>-</i>test.</p

Tissue lead concentrations after 30 days of lead treatment (100 ppm).

<p>Means ± SEM. Number of animals = 7 each group.</p><p>*<i>p</i><0.05, as assessed using Student’s t<i>-</i>test.</p

The effects of endothelium removal (E⁻) (A, B) and <i>N</i>^G-nitro-L-arginine methyl ester (L-NAME, 100 µM) (D, E) on the concentration-response curve for phenylephrine treatment in aortic rings from untreated (CT) and lead-treated rats (Pb⁺²).

<p>The inset shows differences in area under the concentration-response curves (dAUC) in endothelium–denuded and intact segments (C) and in the presence and absence of L-NAME (F). Densitometry analyses of western blots for endothelial nitric oxide synthase (eNOS) and phosphorylated endothelial nitric oxide synthase (p-eNOS) protein expression in aortas from untreated (CT) and lead-treated rats (Pb⁺²) (G). Representative blots are also shown. *P<0.05 by Student's <i>t-</i>test. Number of animals used is indicated in parentheses.</p

Potassium-induced relaxation in aortic rings from untreated (CT) and lead-treated (Pb⁺²) rats previously incubated in a K⁺-free medium and contracted with phenylephrine before and after incubation with 100 µM ouabain (A).

<p>Densitometry analyses of the western blots for the alpha-1 subunit (B) and alpha-2 subunit (C) in aortas from untreated (CT) and lead-treated rats (Pb⁺²). Representative blots are also shown. *P<0.05 (CT <i>vs.</i> Pb⁺²) by Student's <i>t-</i>test or two-way ANOVA followed by a Bonferroni test. ^#P<0.05 (CT OUA <i>vs.</i> Pb⁺² OUA) by two-way ANOVA followed by a Bonferroni test. Number of animals used is indicated in parentheses.</p

Angiotensin converting enzyme (ACE) activity (nmol His-Leu/min) in plasma; correlation between systolic arterial blood pressure and ACE activity (nmol His-Leu/min) in plasma of control and lead-treated rats (r = 0.787, P<0.05).

<p>*P<0.05 by Student's <i>t-</i>test. Number of animals used is indicated in parentheses.</p

The effects of seven-day exposure to lead acetate on the concentration-response curves to phenylephrine (A), acetylcholine (B) and sodium nitroprusside (NSP; C) treatment in aortic rings.

<p>*P<0.05 by Student's <i>t-</i>test. Number of animals used is indicated in parentheses.</p