Effects of aminoguanidine, TEA, losartan and enalapril on the vascular responses to phenylephrine (R_max and pD₂) in aortas from untreated and lead-treated rats.

<p>Results are expressed as mean ± SEM of the number of animals shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0017117#pone-0017117-g003" target="_blank">Figs. 3</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0017117#pone-0017117-g005" target="_blank">5</a> ; R_max, maximal effect (expressed as a percentage of the maximal response induced by 75 mM KCl); pD₂, −log one-half R_max; AG; aminoguanidine, TEA; tetraethylammonium, losartan, enalapril. P<0.05 <i>vs.</i> untreated control rats (^#) and lead-treated control rats (*).</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

Effect of losartan (10 µM) (A, B) and enalapril (10 µM) (C, D) on the concentration-response curves to phenylephrine in endothelium-intact aortic segments from untreated (CT) and lead-treated rats (Pb⁺²).

<p>Densitometry analyses of the western blots for receptors AT₁ (E) and AT₂ (F) in aortas from untreated (CT) and lead-treated rats (Pb⁺²). 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

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

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

Densitometric analysis of the Western blots for endothelial NO synthase (eNOS) protein expression in the isolated aortic rings from Wistar rats (CT, N = 9) and post-weaning protein malnutrition (Malnutrition, N = 9).

<p>The number of preparations is indicated in parenthesis. Each bar represents means ± S.E.M as the ratio between the signal for the eNOS protein and the signal for α-actin. * <i>P<0.05</i> for CT <i>vs.</i> Malnutrition by Student's <i>t</i>-test. Representative blots are shown.</p

(A) Changes in the mean perfusion pressure (MPP) produced by phenylephrine (PHE) in tail vascular beds from the control (CT) and post-weaning protein malnutrition groups (Malnutrition).

<p>(B) Concentration-response curves produced by acetylcholine (ACh) in the tail vascular beds previously contracted with potassium chloride (KCl, 65 mM) (C) Concentration-response curves produced by sodium nitroprusside (SNP) in the tail artery bed previously contracted with with potassium chloride (KCl, 65 mM). The number of preparations is indicated in parenthesis. The results are expressed as the means ± SEM. * <i>P</i><0.05 for Rmax: CT <i>vs.</i> Malnutrition, Student's <i>t-</i>test.</p

Systolic (SBP, mmHg) and diastolic (DBP, mmHg) blood pressure and heart rate (HR, bpm) determination in the control (CT) and post-weaning protein malnutrition (Malnutrition) adult rats.

<p>Values are expressed as the means ± SEM.</p>*<p><i>P</i><0.05 Control <i>vs.</i> Malnutrition, Student <i>t</i>-test.</p

Composition (g/g %) of the Regional Basic Diet (RBD) and the control diet.

1<p>According to the Laboratory of Experimentation and Analysis of Food (LEEAL), Nutrition Department, Federal University of Pernambuco.</p>2<p>As indicated by the manufacturer (Purina Agriband, Paulínia, SP, Brazil).</p