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α-Tocopherol Improves Microcirculatory Dysfunction on Fructose Fed Hamsters.

Boa BC, Barros CM, Souza Md, Castiglione RC, Cyrino FZ, Bouskela E - PLoS ONE (2015)

Bottom Line: On the other hand, vitamin E supplementation resulted in increased responses for both water and fructose drinking groups (177.4% for F vs.The number of leaky sites after I/R and histamine stimuli in vitamin E supplemented animals decreased (-25.1% and -15.3% for F vs.Our results strongly suggest that vitamin E could improve the endothelial function and permeability barrier and also reverse impairments elicited by sugar overload.

View Article: PubMed Central - PubMed

Affiliation: Laboratory for Clinical and Experimental Research on Vascular Biology (BioVasc), Biomedical Center, State University of Rio de Janeiro, Rio de Janeiro, Brazil.

ABSTRACT
Fructose, an everyday component of western diet associated to chronic hyperglycemia and enhanced free radical production, impairs endothelial function and supplementation with antioxidants might improve it. In this study we investigated if vitamin E could reverse the microvascular damage elicited by fructose. Male Syrian golden hamsters drank either 10% fructose solution (F) or filtered water (C), combined with three concentrations of vitamin E in their chows [zero, normal (VE) or 5X (5XVE)] during 60 days. Microvascular reactivity in response to topical application of acetylcholine (Ach; endothelium-dependent vasodilator) or sodium nitroprusside (SNP; endothelium-independent vasodilator) and macromolecular permeability increase induced by either 30 min ischemia followed by reperfusion (I/R) or topical application of histamine (5 μM) were assessed using the cheek pouch preparation. Compared to controls (drinking filtered water), fructose-drinking animals showed decreased vasodilatation to acetylcholine in all concentrations tested (-56.2% for 10-9M, -53.9% for 10-7M and -43.7% for 10-5M). On the other hand, vitamin E supplementation resulted in increased responses for both water and fructose drinking groups (177.4% for F vs. F/5XVE and 241.6% for C vs. C/5XVE for 10-5M Ach). Endothelial-independent vasodilatation explored by topical application of SNP was restored and even enhanced with the supplementation of 5X vitamin E in both groups (80.1% for F vs. F/5XVE; 144.2% for C vs. C/5XVE; 3.4% of difference for C/5XVE vs. F/5XVE on 10-5M SNP). The number of leaky sites after I/R and histamine stimuli in vitamin E supplemented animals decreased (-25.1% and -15.3% for F vs. F/5XVE; and -21.7% and -16% of leaky sites comparing C vs. C/5XVE, respectively for I/R and histamine stimuli) pointing to tightening of the endothelial barrier for macromolecular permeability. Our results strongly suggest that vitamin E could improve the endothelial function and permeability barrier and also reverse impairments elicited by sugar overload.

No MeSH data available.


Related in: MedlinePlus

Mean arteriolar diameters after topical application of SNP–Endothelial- independent evaluation.Data are shown as changes of average diameter, expressed as mean ± SD and plotted in superimposed symbols. (A) Overall mean arteriolar diameters after topical application of three concentrations of sodium nitroprusside (10−9, 10−7 and 10−5 M) in the 2 treated groups. (B) Endothelial-independent responses of groups treated with filtered water, concomitantly associated with chows without vitamin E (C), with normal concentration of vitamin E (75U/kg–C/VE) and supplemented concentrations of vitamin E (375U/kg–C/5XVE). (C) Responses of groups that had the filtered water substituted by 10% fructose solution, concomitantly associated with chows without vitamin E (F), with normal concentration of vitamin E (75U/kg–F/VE) and supplemented concentrations of vitamin E (375U/kg–F/5XVE). +p<0.05 [10-9M and 10-7M] and p<0.01 [10-5M]. Significantly different from Control without vitamin E and #p<0.01 significantly different from fructose-drinking solution without vitamin E.
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pone.0134740.g003: Mean arteriolar diameters after topical application of SNP–Endothelial- independent evaluation.Data are shown as changes of average diameter, expressed as mean ± SD and plotted in superimposed symbols. (A) Overall mean arteriolar diameters after topical application of three concentrations of sodium nitroprusside (10−9, 10−7 and 10−5 M) in the 2 treated groups. (B) Endothelial-independent responses of groups treated with filtered water, concomitantly associated with chows without vitamin E (C), with normal concentration of vitamin E (75U/kg–C/VE) and supplemented concentrations of vitamin E (375U/kg–C/5XVE). (C) Responses of groups that had the filtered water substituted by 10% fructose solution, concomitantly associated with chows without vitamin E (F), with normal concentration of vitamin E (75U/kg–F/VE) and supplemented concentrations of vitamin E (375U/kg–F/5XVE). +p<0.05 [10-9M and 10-7M] and p<0.01 [10-5M]. Significantly different from Control without vitamin E and #p<0.01 significantly different from fructose-drinking solution without vitamin E.

Mentions: Impairments were not limited to endothelial function, but to microvascular function as a whole, since endothelium-independent responses were also decreased after sodium nitroprusside (SNP) application (Fig 3A). The impairment was however limited to animals treated with chows without vitamin E or with normal concentration of it (75U/kg–F/VE) since higher supplementation with vitamin E restored the normal responses on F/5XVE group (treated with 375U/kg of vitamin E) [SNP 10-5M (C/5XVE vs. C– 15.6% decrement of the response) and (C/5XVE vs. C/VE– 26.4% decrement of the response)]. Vitamin E was also responsible for improvements on overall microcirculatory responses, since both fructose-drinking [SNP 10-5M (F/5XVE vs. F–increment of 42.5%) and (F/5XVE vs. F/VE–increment of 44.5%)] and control [SNP 10-5M (C/5XVE vs. C–increment of 51.5%) and (C/5XVE vs. C/VE–increment of 22%)] groups had increased responses when ingested chows with supplemented contents of vitamin E (Fig 3B and 3C).


α-Tocopherol Improves Microcirculatory Dysfunction on Fructose Fed Hamsters.

Boa BC, Barros CM, Souza Md, Castiglione RC, Cyrino FZ, Bouskela E - PLoS ONE (2015)

Mean arteriolar diameters after topical application of SNP–Endothelial- independent evaluation.Data are shown as changes of average diameter, expressed as mean ± SD and plotted in superimposed symbols. (A) Overall mean arteriolar diameters after topical application of three concentrations of sodium nitroprusside (10−9, 10−7 and 10−5 M) in the 2 treated groups. (B) Endothelial-independent responses of groups treated with filtered water, concomitantly associated with chows without vitamin E (C), with normal concentration of vitamin E (75U/kg–C/VE) and supplemented concentrations of vitamin E (375U/kg–C/5XVE). (C) Responses of groups that had the filtered water substituted by 10% fructose solution, concomitantly associated with chows without vitamin E (F), with normal concentration of vitamin E (75U/kg–F/VE) and supplemented concentrations of vitamin E (375U/kg–F/5XVE). +p<0.05 [10-9M and 10-7M] and p<0.01 [10-5M]. Significantly different from Control without vitamin E and #p<0.01 significantly different from fructose-drinking solution without vitamin E.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4526657&req=5

pone.0134740.g003: Mean arteriolar diameters after topical application of SNP–Endothelial- independent evaluation.Data are shown as changes of average diameter, expressed as mean ± SD and plotted in superimposed symbols. (A) Overall mean arteriolar diameters after topical application of three concentrations of sodium nitroprusside (10−9, 10−7 and 10−5 M) in the 2 treated groups. (B) Endothelial-independent responses of groups treated with filtered water, concomitantly associated with chows without vitamin E (C), with normal concentration of vitamin E (75U/kg–C/VE) and supplemented concentrations of vitamin E (375U/kg–C/5XVE). (C) Responses of groups that had the filtered water substituted by 10% fructose solution, concomitantly associated with chows without vitamin E (F), with normal concentration of vitamin E (75U/kg–F/VE) and supplemented concentrations of vitamin E (375U/kg–F/5XVE). +p<0.05 [10-9M and 10-7M] and p<0.01 [10-5M]. Significantly different from Control without vitamin E and #p<0.01 significantly different from fructose-drinking solution without vitamin E.
Mentions: Impairments were not limited to endothelial function, but to microvascular function as a whole, since endothelium-independent responses were also decreased after sodium nitroprusside (SNP) application (Fig 3A). The impairment was however limited to animals treated with chows without vitamin E or with normal concentration of it (75U/kg–F/VE) since higher supplementation with vitamin E restored the normal responses on F/5XVE group (treated with 375U/kg of vitamin E) [SNP 10-5M (C/5XVE vs. C– 15.6% decrement of the response) and (C/5XVE vs. C/VE– 26.4% decrement of the response)]. Vitamin E was also responsible for improvements on overall microcirculatory responses, since both fructose-drinking [SNP 10-5M (F/5XVE vs. F–increment of 42.5%) and (F/5XVE vs. F/VE–increment of 44.5%)] and control [SNP 10-5M (C/5XVE vs. C–increment of 51.5%) and (C/5XVE vs. C/VE–increment of 22%)] groups had increased responses when ingested chows with supplemented contents of vitamin E (Fig 3B and 3C).

Bottom Line: On the other hand, vitamin E supplementation resulted in increased responses for both water and fructose drinking groups (177.4% for F vs.The number of leaky sites after I/R and histamine stimuli in vitamin E supplemented animals decreased (-25.1% and -15.3% for F vs.Our results strongly suggest that vitamin E could improve the endothelial function and permeability barrier and also reverse impairments elicited by sugar overload.

View Article: PubMed Central - PubMed

Affiliation: Laboratory for Clinical and Experimental Research on Vascular Biology (BioVasc), Biomedical Center, State University of Rio de Janeiro, Rio de Janeiro, Brazil.

ABSTRACT
Fructose, an everyday component of western diet associated to chronic hyperglycemia and enhanced free radical production, impairs endothelial function and supplementation with antioxidants might improve it. In this study we investigated if vitamin E could reverse the microvascular damage elicited by fructose. Male Syrian golden hamsters drank either 10% fructose solution (F) or filtered water (C), combined with three concentrations of vitamin E in their chows [zero, normal (VE) or 5X (5XVE)] during 60 days. Microvascular reactivity in response to topical application of acetylcholine (Ach; endothelium-dependent vasodilator) or sodium nitroprusside (SNP; endothelium-independent vasodilator) and macromolecular permeability increase induced by either 30 min ischemia followed by reperfusion (I/R) or topical application of histamine (5 μM) were assessed using the cheek pouch preparation. Compared to controls (drinking filtered water), fructose-drinking animals showed decreased vasodilatation to acetylcholine in all concentrations tested (-56.2% for 10-9M, -53.9% for 10-7M and -43.7% for 10-5M). On the other hand, vitamin E supplementation resulted in increased responses for both water and fructose drinking groups (177.4% for F vs. F/5XVE and 241.6% for C vs. C/5XVE for 10-5M Ach). Endothelial-independent vasodilatation explored by topical application of SNP was restored and even enhanced with the supplementation of 5X vitamin E in both groups (80.1% for F vs. F/5XVE; 144.2% for C vs. C/5XVE; 3.4% of difference for C/5XVE vs. F/5XVE on 10-5M SNP). The number of leaky sites after I/R and histamine stimuli in vitamin E supplemented animals decreased (-25.1% and -15.3% for F vs. F/5XVE; and -21.7% and -16% of leaky sites comparing C vs. C/5XVE, respectively for I/R and histamine stimuli) pointing to tightening of the endothelial barrier for macromolecular permeability. Our results strongly suggest that vitamin E could improve the endothelial function and permeability barrier and also reverse impairments elicited by sugar overload.

No MeSH data available.


Related in: MedlinePlus