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

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

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

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

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

Changes in arterial pressure.

<p>Changes in systolic arterial pressure-SAP (A and C) and diastolic arterial pressure-DAP (B and D) before (Ct) and after Losartan (Los) or Enalapril (Enal) administration and following lead exposure (Los+Pb; Enal+Pb). A and B show the Losartan protocol; C and D show the Enalapril protocol. *p<0.05 compared with untreated controls. The number of animals used is indicated in parentheses.</p

Effects of lead on protein expression and ACE activity.

<p>Effects of lead exposure on the protein expression of the (A) AT1 and (B) AT2 receptors and on (C) ACE activity. *p<0.05 compared with untreated controls. The number of animals used is indicated in parentheses.</p

Hemodynamic parameters upon acute lead exposure.

<p>SAP- systolic arterial pressure, DAP- diastolic arterial pressure, HR- heart rate, Ct- Control. The results are expressed as the mean ± SEM.</p><p>*p<0.05 compared with controls (time 0); n = 10.</p

Changes in arterial pressure.

<p>Changes in systolic arterial pressure (SAP) and diastolic arterial pressure (DAP) before (Ct) and after Hexamethonium (Hexa) administration and following lead exposure (Hexa+Pb). *p<0.05 compared with untreated controls. The number of animals used is indicated in parentheses.</p