Limits...
Aerobic Exercise Training Prevents the Onset of Endothelial Dysfunction via Increased Nitric Oxide Bioavailability and Reduced Reactive Oxygen Species in an Experimental Model of Menopause.

Braga VA, Couto GK, Lazzarin MC, Rossoni LV, Medeiros A - PLoS ONE (2015)

Bottom Line: Training prevented this response in OVX-TRA (Rmax: OVX-TRA: 88±2.0%, p<0.01), while did not change it in SHAM-TRA (Rmax: SHAM-TRA: 80±2.2%, p<0.01).The L-NAME incubation abolished the differences in ACh-induced relaxation among groups.OVX reduced nitrite/nitrate plasma concentrations and increased ROS in aortic slices, training as effective to restore these parameters to the SHAM levels.

View Article: PubMed Central - PubMed

Affiliation: Department of Biosciences, Federal University of Sao Paulo, Santos, Sao Paulo, Brazil.

ABSTRACT

Objective: Previous studies have shown that estrogen deficiency, arising in postmenopause, promotes endothelial dysfunction. This study evaluated the effects of aerobic exercise training on endothelial dependent vasodilation of aorta in ovariectomized rats, specifically investigating the role of nitric oxide (NO) and reactive oxygen species (ROS).

Methods: Female Wistar rats ovariectomized (OVX - n=20) or with intact ovary (SHAM - n=20) remained sedentary (OVX and SHAM) or performed aerobic exercise training on a treadmill 5 times a week for a period of 8 weeks (OVX-TRA and SHAM-TRA). In the thoracic aorta the endothelium-dependent and -independent vasodilation was assessed by acetylcholine (ACh) and sodium nitroprusside (SNP), respectively. Certain aortic rings were incubated with L-NAME to assess the NO modulation on the ACh-induced vasodilation. The fluorescence to dihydroethidium in aortic slices and plasma nitrite/nitrate concentrations were measured to evaluate ROS and NO bioavailability, respectively.

Results: ACh-induced vasodilation was reduced in OVX rats as compared SHAM (Rmax: SHAM: 86±3.3 vs. OVX: 57±3.0%, p<0.01). Training prevented this response in OVX-TRA (Rmax: OVX-TRA: 88±2.0%, p<0.01), while did not change it in SHAM-TRA (Rmax: SHAM-TRA: 80±2.2%, p<0.01). The L-NAME incubation abolished the differences in ACh-induced relaxation among groups. SNP-induced vasodilation was not different among groups. OVX reduced nitrite/nitrate plasma concentrations and increased ROS in aortic slices, training as effective to restore these parameters to the SHAM levels.

Conclusions: Exercise training, even in estrogen deficiency conditions, is able to improve endothelial dependent vasodilation in rat aorta via enhanced NO bioavailability and reduced ROS levels.

Show MeSH

Related in: MedlinePlus

Representative images of aortic slices from SHAM, SHAM-TRA, OVX and OVX-TRA rats, in the absence (upper panel) and presence (lower panel) of the superoxide dismutase mimetic, MnTMPyP (A). Quantification of fluorescence intensity emitted by DHE oxidation in aortic slices in the absence and presence of the MnTMPyP as an indicative of reactive oxygen species in SHAM, SHAM-TRA, OVX and OVX-TRA rats (B).The numbers shown in bars represent the number of animals analyzed in each group. Results are expressed as means±SEM. Two-way ANOVA: *p<0.01 in comparison to SHAM, # p<0.01 in comparison to OVX.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4414603&req=5

pone.0125388.g004: Representative images of aortic slices from SHAM, SHAM-TRA, OVX and OVX-TRA rats, in the absence (upper panel) and presence (lower panel) of the superoxide dismutase mimetic, MnTMPyP (A). Quantification of fluorescence intensity emitted by DHE oxidation in aortic slices in the absence and presence of the MnTMPyP as an indicative of reactive oxygen species in SHAM, SHAM-TRA, OVX and OVX-TRA rats (B).The numbers shown in bars represent the number of animals analyzed in each group. Results are expressed as means±SEM. Two-way ANOVA: *p<0.01 in comparison to SHAM, # p<0.01 in comparison to OVX.

Mentions: To assess the production of ROS in the aorta, we used fluorescence emitted by DHE in the presence and absence of the mimic of superoxide dismutase (SOD), the MnTMPyP (25 μM), as an indicative of superoxide anion bioavailability. As seen in Fig 4, the intensity of fluorescence emitted by DHE was higher in the aorta of OVX rats when compared to SHAM rats, indicating an increased level of ROS. Aerobic exercise training reduced ROS levels in the aorta of OVX-TRA to SHAM levels and did not alter it in SHAM-TRA aortas. The mimic of superoxide dismutase (SOD), the MnTMPyP, blocked the differences among aortas of studied groups, suggesting that the superoxide anion is the major ROS produced in OVX aorta, which is modulated by exercise training (Fig 4).


Aerobic Exercise Training Prevents the Onset of Endothelial Dysfunction via Increased Nitric Oxide Bioavailability and Reduced Reactive Oxygen Species in an Experimental Model of Menopause.

Braga VA, Couto GK, Lazzarin MC, Rossoni LV, Medeiros A - PLoS ONE (2015)

Representative images of aortic slices from SHAM, SHAM-TRA, OVX and OVX-TRA rats, in the absence (upper panel) and presence (lower panel) of the superoxide dismutase mimetic, MnTMPyP (A). Quantification of fluorescence intensity emitted by DHE oxidation in aortic slices in the absence and presence of the MnTMPyP as an indicative of reactive oxygen species in SHAM, SHAM-TRA, OVX and OVX-TRA rats (B).The numbers shown in bars represent the number of animals analyzed in each group. Results are expressed as means±SEM. Two-way ANOVA: *p<0.01 in comparison to SHAM, # p<0.01 in comparison to OVX.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4414603&req=5

pone.0125388.g004: Representative images of aortic slices from SHAM, SHAM-TRA, OVX and OVX-TRA rats, in the absence (upper panel) and presence (lower panel) of the superoxide dismutase mimetic, MnTMPyP (A). Quantification of fluorescence intensity emitted by DHE oxidation in aortic slices in the absence and presence of the MnTMPyP as an indicative of reactive oxygen species in SHAM, SHAM-TRA, OVX and OVX-TRA rats (B).The numbers shown in bars represent the number of animals analyzed in each group. Results are expressed as means±SEM. Two-way ANOVA: *p<0.01 in comparison to SHAM, # p<0.01 in comparison to OVX.
Mentions: To assess the production of ROS in the aorta, we used fluorescence emitted by DHE in the presence and absence of the mimic of superoxide dismutase (SOD), the MnTMPyP (25 μM), as an indicative of superoxide anion bioavailability. As seen in Fig 4, the intensity of fluorescence emitted by DHE was higher in the aorta of OVX rats when compared to SHAM rats, indicating an increased level of ROS. Aerobic exercise training reduced ROS levels in the aorta of OVX-TRA to SHAM levels and did not alter it in SHAM-TRA aortas. The mimic of superoxide dismutase (SOD), the MnTMPyP, blocked the differences among aortas of studied groups, suggesting that the superoxide anion is the major ROS produced in OVX aorta, which is modulated by exercise training (Fig 4).

Bottom Line: Training prevented this response in OVX-TRA (Rmax: OVX-TRA: 88±2.0%, p<0.01), while did not change it in SHAM-TRA (Rmax: SHAM-TRA: 80±2.2%, p<0.01).The L-NAME incubation abolished the differences in ACh-induced relaxation among groups.OVX reduced nitrite/nitrate plasma concentrations and increased ROS in aortic slices, training as effective to restore these parameters to the SHAM levels.

View Article: PubMed Central - PubMed

Affiliation: Department of Biosciences, Federal University of Sao Paulo, Santos, Sao Paulo, Brazil.

ABSTRACT

Objective: Previous studies have shown that estrogen deficiency, arising in postmenopause, promotes endothelial dysfunction. This study evaluated the effects of aerobic exercise training on endothelial dependent vasodilation of aorta in ovariectomized rats, specifically investigating the role of nitric oxide (NO) and reactive oxygen species (ROS).

Methods: Female Wistar rats ovariectomized (OVX - n=20) or with intact ovary (SHAM - n=20) remained sedentary (OVX and SHAM) or performed aerobic exercise training on a treadmill 5 times a week for a period of 8 weeks (OVX-TRA and SHAM-TRA). In the thoracic aorta the endothelium-dependent and -independent vasodilation was assessed by acetylcholine (ACh) and sodium nitroprusside (SNP), respectively. Certain aortic rings were incubated with L-NAME to assess the NO modulation on the ACh-induced vasodilation. The fluorescence to dihydroethidium in aortic slices and plasma nitrite/nitrate concentrations were measured to evaluate ROS and NO bioavailability, respectively.

Results: ACh-induced vasodilation was reduced in OVX rats as compared SHAM (Rmax: SHAM: 86±3.3 vs. OVX: 57±3.0%, p<0.01). Training prevented this response in OVX-TRA (Rmax: OVX-TRA: 88±2.0%, p<0.01), while did not change it in SHAM-TRA (Rmax: SHAM-TRA: 80±2.2%, p<0.01). The L-NAME incubation abolished the differences in ACh-induced relaxation among groups. SNP-induced vasodilation was not different among groups. OVX reduced nitrite/nitrate plasma concentrations and increased ROS in aortic slices, training as effective to restore these parameters to the SHAM levels.

Conclusions: Exercise training, even in estrogen deficiency conditions, is able to improve endothelial dependent vasodilation in rat aorta via enhanced NO bioavailability and reduced ROS levels.

Show MeSH
Related in: MedlinePlus