Limits...
Different Anti-Contractile Function and Nitric Oxide Production of Thoracic and Abdominal Perivascular Adipose Tissues.

Victorio JA, Fontes MT, Rossoni LV, Davel AP - Front Physiol (2016)

Bottom Line: PVAT reduced the contraction evoked by phenylephrine in the absence and presence of endothelium in the thoracic aorta, whereas this anti-contractile effect was not observed in the abdominal aorta.However, Mn-SOD levels were reduced, while CuZn-SOD levels were increased in abdominal PVAT compared with thoracic aortic PVAT.In conclusion, our results demonstrate that the anti-contractile function of PVAT is lost in the abdominal portion of the aorta through a reduction in eNOS-derived NO production compared with the thoracic aorta.

View Article: PubMed Central - PubMed

Affiliation: Department of Structural and Functional Biology, Institute of Biology, University of Campinas Campinas, Brazil.

ABSTRACT
Divergent phenotypes between the perivascular adipose tissue (PVAT) surrounding the abdominal and the thoracic aorta might be implicated in regional aortic differences, such as susceptibility to atherosclerosis. Although PVAT of the thoracic aorta exhibits anti-contractile function, the role of PVAT in the regulation of the vascular tone of the abdominal aorta is not well defined. In the present study, we compared the anti-contractile function, nitric oxide (NO) availability, and reactive oxygen species (ROS) formation in PVAT and vessel walls of abdominal and thoracic aorta. Abdominal and thoracic aortic tissue from male Wistar rats were used to perform functional and molecular experiments. PVAT reduced the contraction evoked by phenylephrine in the absence and presence of endothelium in the thoracic aorta, whereas this anti-contractile effect was not observed in the abdominal aorta. Abdominal PVAT exhibited a reduction in endothelial NO synthase (eNOS) expression compared with thoracic PVAT, without differences in eNOS expression in the vessel walls. In agreement with this result, NO production evaluated in situ using 4,5-diaminofluorescein was less pronounced in abdominal compared with thoracic aortic PVAT, whereas no significant difference was observed for endothelial NO production. Moreover, NOS inhibition with L-NAME enhanced the phenylephrine-induced contraction in endothelial-denuded rings with PVAT from thoracic but not abdominal aorta. ROS formation and lipid peroxidation products evaluated through the quantification of hydroethidine fluorescence and 4-hydroxynonenal adducts, respectively, were similar between PVAT and vessel walls from the abdominal and thoracic aorta. Extracellular superoxide dismutase (SOD) expression was similar between the vessel walls and PVAT of the abdominal and thoracic aorta. However, Mn-SOD levels were reduced, while CuZn-SOD levels were increased in abdominal PVAT compared with thoracic aortic PVAT. In conclusion, our results demonstrate that the anti-contractile function of PVAT is lost in the abdominal portion of the aorta through a reduction in eNOS-derived NO production compared with the thoracic aorta. Although relative SOD isoforms are different along the aorta, ROS formation, and lipid peroxidation seem to be similar. These findings highlight the specific regional roles of PVAT depots in the control of vascular function that can drive differences in susceptibility to vascular injury.

No MeSH data available.


Related in: MedlinePlus

Comparative protein expression levels of superoxide dismutase (SOD) isoenzymes in thoracic (THO) and abdominal (ABD) aortic tissues. Protein expression of extracellular (EC)-SOD (A), Mn-SOD (B), and cytoplasmatic CuZn-SOD (C) in vessel walls and perivascular adipose tissue (PVAT) from THO and ABD aorta. Representative blots and Ponceau S staining were demonstrated at the upper panels of the figures and densitometric analysis is expressed as the fold change of THO expression at the bottom panel. Data are expressed as the means ± SEM; the number of animals is indicated in the bars of the graph. Student's t-test, P < 0.05: *ABD vs. THO PVAT.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4940415&req=5

Figure 4: Comparative protein expression levels of superoxide dismutase (SOD) isoenzymes in thoracic (THO) and abdominal (ABD) aortic tissues. Protein expression of extracellular (EC)-SOD (A), Mn-SOD (B), and cytoplasmatic CuZn-SOD (C) in vessel walls and perivascular adipose tissue (PVAT) from THO and ABD aorta. Representative blots and Ponceau S staining were demonstrated at the upper panels of the figures and densitometric analysis is expressed as the fold change of THO expression at the bottom panel. Data are expressed as the means ± SEM; the number of animals is indicated in the bars of the graph. Student's t-test, P < 0.05: *ABD vs. THO PVAT.

Mentions: The protein expression levels of SOD isoforms were investigated in abdominal and thoracic tissues. EC-SOD did not differ between abdominal and thoracic aortic tissues and PVAT (Figure 4A), while reduced Mn-SOD expression was detected in abdominal compared with thoracic PVAT, without changes in the vascular wall (Figure 4B). In contrast, CuZn-SOD expression was increased in abdominal PVAT compared to thoracic PVAT, with no regional differences in the aortic wall (Figure 4C).


Different Anti-Contractile Function and Nitric Oxide Production of Thoracic and Abdominal Perivascular Adipose Tissues.

Victorio JA, Fontes MT, Rossoni LV, Davel AP - Front Physiol (2016)

Comparative protein expression levels of superoxide dismutase (SOD) isoenzymes in thoracic (THO) and abdominal (ABD) aortic tissues. Protein expression of extracellular (EC)-SOD (A), Mn-SOD (B), and cytoplasmatic CuZn-SOD (C) in vessel walls and perivascular adipose tissue (PVAT) from THO and ABD aorta. Representative blots and Ponceau S staining were demonstrated at the upper panels of the figures and densitometric analysis is expressed as the fold change of THO expression at the bottom panel. Data are expressed as the means ± SEM; the number of animals is indicated in the bars of the graph. Student's t-test, P < 0.05: *ABD vs. THO PVAT.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4940415&req=5

Figure 4: Comparative protein expression levels of superoxide dismutase (SOD) isoenzymes in thoracic (THO) and abdominal (ABD) aortic tissues. Protein expression of extracellular (EC)-SOD (A), Mn-SOD (B), and cytoplasmatic CuZn-SOD (C) in vessel walls and perivascular adipose tissue (PVAT) from THO and ABD aorta. Representative blots and Ponceau S staining were demonstrated at the upper panels of the figures and densitometric analysis is expressed as the fold change of THO expression at the bottom panel. Data are expressed as the means ± SEM; the number of animals is indicated in the bars of the graph. Student's t-test, P < 0.05: *ABD vs. THO PVAT.
Mentions: The protein expression levels of SOD isoforms were investigated in abdominal and thoracic tissues. EC-SOD did not differ between abdominal and thoracic aortic tissues and PVAT (Figure 4A), while reduced Mn-SOD expression was detected in abdominal compared with thoracic PVAT, without changes in the vascular wall (Figure 4B). In contrast, CuZn-SOD expression was increased in abdominal PVAT compared to thoracic PVAT, with no regional differences in the aortic wall (Figure 4C).

Bottom Line: PVAT reduced the contraction evoked by phenylephrine in the absence and presence of endothelium in the thoracic aorta, whereas this anti-contractile effect was not observed in the abdominal aorta.However, Mn-SOD levels were reduced, while CuZn-SOD levels were increased in abdominal PVAT compared with thoracic aortic PVAT.In conclusion, our results demonstrate that the anti-contractile function of PVAT is lost in the abdominal portion of the aorta through a reduction in eNOS-derived NO production compared with the thoracic aorta.

View Article: PubMed Central - PubMed

Affiliation: Department of Structural and Functional Biology, Institute of Biology, University of Campinas Campinas, Brazil.

ABSTRACT
Divergent phenotypes between the perivascular adipose tissue (PVAT) surrounding the abdominal and the thoracic aorta might be implicated in regional aortic differences, such as susceptibility to atherosclerosis. Although PVAT of the thoracic aorta exhibits anti-contractile function, the role of PVAT in the regulation of the vascular tone of the abdominal aorta is not well defined. In the present study, we compared the anti-contractile function, nitric oxide (NO) availability, and reactive oxygen species (ROS) formation in PVAT and vessel walls of abdominal and thoracic aorta. Abdominal and thoracic aortic tissue from male Wistar rats were used to perform functional and molecular experiments. PVAT reduced the contraction evoked by phenylephrine in the absence and presence of endothelium in the thoracic aorta, whereas this anti-contractile effect was not observed in the abdominal aorta. Abdominal PVAT exhibited a reduction in endothelial NO synthase (eNOS) expression compared with thoracic PVAT, without differences in eNOS expression in the vessel walls. In agreement with this result, NO production evaluated in situ using 4,5-diaminofluorescein was less pronounced in abdominal compared with thoracic aortic PVAT, whereas no significant difference was observed for endothelial NO production. Moreover, NOS inhibition with L-NAME enhanced the phenylephrine-induced contraction in endothelial-denuded rings with PVAT from thoracic but not abdominal aorta. ROS formation and lipid peroxidation products evaluated through the quantification of hydroethidine fluorescence and 4-hydroxynonenal adducts, respectively, were similar between PVAT and vessel walls from the abdominal and thoracic aorta. Extracellular superoxide dismutase (SOD) expression was similar between the vessel walls and PVAT of the abdominal and thoracic aorta. However, Mn-SOD levels were reduced, while CuZn-SOD levels were increased in abdominal PVAT compared with thoracic aortic PVAT. In conclusion, our results demonstrate that the anti-contractile function of PVAT is lost in the abdominal portion of the aorta through a reduction in eNOS-derived NO production compared with the thoracic aorta. Although relative SOD isoforms are different along the aorta, ROS formation, and lipid peroxidation seem to be similar. These findings highlight the specific regional roles of PVAT depots in the control of vascular function that can drive differences in susceptibility to vascular injury.

No MeSH data available.


Related in: MedlinePlus