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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

Experimental design and protocol.(1A) Eight weeks-old hamsters were treated during 8 weeks as described: animals were divided into two major groups, substitution of the drinking water by 10% fructose solution or kept drinking filtered water. Each major group had the formulated chow associated to three different concentrations of vitamin E: zero vitamin E (groups F and C), 75U/kg (normal concentration of vitamin E—groups F/VE and C/VE) and 375U/kg (5 times the normal concentration of vitamin E—groups F/5XVE and C/5XVE). After the 8th week of treatment, the hamster cheek pouch microcirculation was evaluated by intravital microscopy and animals were euthanized for blood collection. (1B) Microcirculatory function was evaluated in two fronts: endothelial function by topical application of either acetylcholine or sodium nitroprusside, both in three different concentrations (10−9, 10−7 and 10-5M), in a cumulative dose-response curve and macromolecular permeability increase induced by either ischemia/reperfusion (30 min local ischemia followed by reperfusion) or topical application of histamine (5 μM during 5 min).
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pone.0134740.g001: Experimental design and protocol.(1A) Eight weeks-old hamsters were treated during 8 weeks as described: animals were divided into two major groups, substitution of the drinking water by 10% fructose solution or kept drinking filtered water. Each major group had the formulated chow associated to three different concentrations of vitamin E: zero vitamin E (groups F and C), 75U/kg (normal concentration of vitamin E—groups F/VE and C/VE) and 375U/kg (5 times the normal concentration of vitamin E—groups F/5XVE and C/5XVE). After the 8th week of treatment, the hamster cheek pouch microcirculation was evaluated by intravital microscopy and animals were euthanized for blood collection. (1B) Microcirculatory function was evaluated in two fronts: endothelial function by topical application of either acetylcholine or sodium nitroprusside, both in three different concentrations (10−9, 10−7 and 10-5M), in a cumulative dose-response curve and macromolecular permeability increase induced by either ischemia/reperfusion (30 min local ischemia followed by reperfusion) or topical application of histamine (5 μM during 5 min).

Mentions: Nutritional characteristics of the experimental chow are exposed in Table 1. Water and rodent chow were autoclaved at the State University of Rio de Janeiro (Laboratory for Clinical and Experimental Research in Vascular Biology, Rio de Janeiro, Brazil) and provided ad libitum. Food and water intake were weekly monitored during the experimental period as exposed in Table 2. Experimental design and groups are presented on Fig 1.


α-Tocopherol Improves Microcirculatory Dysfunction on Fructose Fed Hamsters.

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

Experimental design and protocol.(1A) Eight weeks-old hamsters were treated during 8 weeks as described: animals were divided into two major groups, substitution of the drinking water by 10% fructose solution or kept drinking filtered water. Each major group had the formulated chow associated to three different concentrations of vitamin E: zero vitamin E (groups F and C), 75U/kg (normal concentration of vitamin E—groups F/VE and C/VE) and 375U/kg (5 times the normal concentration of vitamin E—groups F/5XVE and C/5XVE). After the 8th week of treatment, the hamster cheek pouch microcirculation was evaluated by intravital microscopy and animals were euthanized for blood collection. (1B) Microcirculatory function was evaluated in two fronts: endothelial function by topical application of either acetylcholine or sodium nitroprusside, both in three different concentrations (10−9, 10−7 and 10-5M), in a cumulative dose-response curve and macromolecular permeability increase induced by either ischemia/reperfusion (30 min local ischemia followed by reperfusion) or topical application of histamine (5 μM during 5 min).
© Copyright Policy
Related In: Results  -  Collection

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

pone.0134740.g001: Experimental design and protocol.(1A) Eight weeks-old hamsters were treated during 8 weeks as described: animals were divided into two major groups, substitution of the drinking water by 10% fructose solution or kept drinking filtered water. Each major group had the formulated chow associated to three different concentrations of vitamin E: zero vitamin E (groups F and C), 75U/kg (normal concentration of vitamin E—groups F/VE and C/VE) and 375U/kg (5 times the normal concentration of vitamin E—groups F/5XVE and C/5XVE). After the 8th week of treatment, the hamster cheek pouch microcirculation was evaluated by intravital microscopy and animals were euthanized for blood collection. (1B) Microcirculatory function was evaluated in two fronts: endothelial function by topical application of either acetylcholine or sodium nitroprusside, both in three different concentrations (10−9, 10−7 and 10-5M), in a cumulative dose-response curve and macromolecular permeability increase induced by either ischemia/reperfusion (30 min local ischemia followed by reperfusion) or topical application of histamine (5 μM during 5 min).
Mentions: Nutritional characteristics of the experimental chow are exposed in Table 1. Water and rodent chow were autoclaved at the State University of Rio de Janeiro (Laboratory for Clinical and Experimental Research in Vascular Biology, Rio de Janeiro, Brazil) and provided ad libitum. Food and water intake were weekly monitored during the experimental period as exposed in Table 2. Experimental design and groups are presented on Fig 1.

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