PDE-5 inhibition with sildenafil does not increase dipropylenetriamine NONOate (DPTA-NO) side-effects in cardiovascular parameters.

<p>Changes in mean arterial pressure (MAP, A), systolic pressure (B), diastolic pressure (C), pulse pressure (D) and heart rate (E) following one IP injection of saline (black dots and lines), DPTA-NO (1 and 0.1 mg/mouse, red and blue dots and lines, respectively), sildenafil (0.1 mg/mouse, green dots and lines), and DPTA-NO+sildenafil (0.1 mg/mouse of each drug, purple dots and lines). Vertical doted lines represent the time when the IP injection was given and separate the baseline period from the experimental period. Results are expressed as the percentage change in relation to the mean of the baseline period for each group. Horizontal doted lines represent the range of values falling within the mean plus and minus two standard deviations (SD) of the baseline value calculated for saline treated group. n = 4 per group.</p

PDE-5 inhibition with sildenafil decreases the amount of dipropylenetriamine NONOate (DPTA-NO) necessary to prevent ECM.

<p>Cumulative survival (A), course of parasitemia (B), rectal temperature (C), and motor behavior score (D) of PbA-infected mice treated with saline (n = 29), DPTA-NO (1, 0.1 or 0.01 mg/mouse, n = 10 per group), DPTA-NO+sildenafil (0.1 mg/mouse of each drug, n = 18), and sildenafil (0.1 mg/mouse, n = 19). Plasma nitrite (E) and hematocrit (F) from selected groups were measured on samples collected prior to the morning dosing on day 6 of infection (n≥5 per group). *p<0.05, **p<0.01, ***p<0.001, arrows indicate the presence of a linear trend.</p

PDE-5 inhibition with sildenafil or sodium nitrite (NaNO₂) supplementation did not prevent ECM.

<p>Cumulative survival (A), course of parasitemia (B), rectal temperature (C), and motor behavior score (D) of PbA-infected mice prophylactic treated with saline (n = 28), NaNO₂ (n = 13), and sildenafil at 0.1 (n = 19), 0.01 (n = 12) or 0.001(n = 5) mg/mouse. Rectal temperature and motor behavior score were measured on day 6 of infection. There were no significant differences in the parameters analyzed (p>0.05 for all comparisons).</p

L-arginine and/or tetrahydro-L-Biopterin (BH4) supplementation combined or not with arginase inhibition did not prevent ECM.

<p>Cumulative survival (A), course of parasitemia (B), rectal temperature (C), and motor behavior score (D) of PbA-infected mice treated with bolus injections of saline (n = 22), L-arginine 4 mg/mouse (n = 9), the arginase inhibitor Nω-hydroxy-nor-Arginine (nor-NOHA) 250 µg/mouse (n = 15), BH4 1 mg/mouse (n = 9), nor-NOHA+L-arginine (n = 16), and nor-NOHA+L-arginine+BH4 (n = 9). Rectal temperature and motor behavior score were measured on day 6 of infection. Exhaled NO (E) from selected groups was measured 1 hour after the morning treatment on day 5 of infection (n≥5 per group). Plasma nitrite (F) from selected groups treated with bolus injections. Cumulative survival (<b>G</b>) and plasma nitrite (<b>H</b>) of PbA-infected mice prophylactic treated with continuous L-arginine or saline supplementation using implanted osmotic pumps (n = 10 per group). Plasma nitrite (F, H) was measured on samples collected prior to the morning dosing on day 6 of infection (n≥5 per group). *p<0.05, **p<0.01, ***p<0.001, arrows indicate the presence of a linear trend.</p

Transgenic mice exhibit significant increases in empty lacunae and intracortical cavities.

<p>(A) Quantification of empty lacunae in cortical and trabecular bone. (B) Quantification of intracortical cavities.</p

Schematic demonstrating two potential mechanisms by which osteocyte ablation may give rise to loss of trabecular bone mass in unpressurized limbs while enhancing pressure loading-induced adaptation.

<p>In the first case (A), osteocyte ablation gives rise to an increase in the number of active osteoclasts, resulting in heightened bone loss in unpressurized limbs. In limbs subjected to pressure loading, the resorptive activity of these active osteoclasts is halted, preserving bone mass. In the second case (B), osteocyte ablation shifts the osteoblastic population to a more quiescent state, resulting in decreased bone mass in unpressurized limbs. However, in pressure-loaded limbs, an enhanced anabolic response occurs due to the newly available pool of quiescent cells activated following exposure to pressure loading-induced IFF.</p

Quantification of canalicular convective velocity from <i>ex vivo</i> measurements of lacunar fluorescence recovery after photobleaching.

<p>(A) Single lacuna immediately prior to (Pre-Bleach) and following photobleaching (Bleach), and the subsequent recovery of fluorescence in the absence (top) and presence (bottom) of pressure loading. Faster recovery can be observed in the presence of pressure loading, indicating convective transport. Color bar on bottom indicates image intensity. (B) Plot of Eq. 1 demonstrating the relationship between convective velocity <i>v_c</i> and recovery rates <i>k</i> and <i>k</i>₀. The red dot corresponds to the canalicular fluid velocity (∼80 µm/s) calculated using the values of <i>k</i> and <i>k</i>₀ obtained in this study.</p

Pressure loading-induced adaptation is enhanced in transgenic mice.

<p>Results are shown for relative changes (defined as the difference between pressure-loaded limb and contralateral limb values) in (A) trabecular volume fraction, (B) trabecular number, (C) trabecular spacing, (D) cortical thickness, and (E) bone mineral density.</p

Bone structure and bone mineral density in control limbs.

<p>^gand ^s indicate statistically significant for genotype or suspension, respectively.</p

Bone structure in control limb predicts inter- and intra-group variability in adaptation to pressure loading.

<p>Bone structure in control limb is plotted in the x-coordinate, and is indicative of baseline cellular activity in the absence of pressure loading. Relative adaptation is plotted in the y-coordinate, and was found to be negatively correlated with control limb structure independently of genotype and DT dose. Results are shown for (A) trabecular volume fraction, (B) trabecular number, (C) trabecular spacing, (D) cortical thickness, and (E) bone mineral density. Each point represents a single animal (red: WT; blue: Tg; circle: 10 µg/kg DT; square: 50 µg/kg DT; fill: HLS; no fill: Amb). Pearson correlation coefficients and corresponding p-values are shown in the top right of each plot.</p