Perivascular Adipose Tissue Anticontractile Function Is Mediated by Both Endothelial and Neuronal Nitric Oxide Synthase Isoforms

Figures

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  Fig. 1. Loss of PVAT anticontractile function in obesity is due to dysfunctional PVAT. Mesenteric (a, c) and gracilis (b, d) resistance arteries were isolated from control (a, b) and obese mice (c, d). Arteries were subjected to EFS in the presence and absence of PVAT harvested from either control mice or obese mice, which was suspended above the artery in the organ bath (a −PVAT vs. control PVAT p < 0.01**, −PVAT vs. obese PVAT p > 0.05, control PVAT vs. obese PVAT p < 0.001+++. b −PVAT vs. control PVAT p < 0.0001****, −PVAT vs. obese PVAT p > 0.05, control PVAT vs. obese PVAT p < 0.0001++++. c −PVAT vs. control PVAT p < 0.0001****, −PVAT vs. obese PVAT p > 0.05, control PVAT vs. obese PVAT p < 0.000++++. d −PVAT vs. control PVAT p < 0.0001****, −PVAT vs. obese PVAT p > 0.05, control PVAT vs. obese PVAT p < 0.0001++++). The responses of −PVAT control and obese mesenteric arteries shown in (a, c) are compared in (e) (control −PVAT vs. obese −PVAT p < 0.01**). The responses of −PVAT control and obese gracilis arteries shown in (b, d) are compared in (f) (control −PVAT vs. obese −PVAT p < 0.0001****). Data shown are mean ± SEM (n = 7 all groups) (two-way ANOVAs with Bonferroni post hoc…

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  Fig. 2. EF50 and Emax are no different between lean control and obese mesenteric and gracilis arteries. The EF50 and Emax from Figure 1e and f were calculated for mesenteric (a) and gracilis (b) lean control and obese arteries. Data shown are mean ± SEM (n = 7 all groups) (p > 0.05 all comparisons, unpaired t test).

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  Fig. 3. PVAT anticontractile effect in gracilis arteries is mediated via β3-adrenoceptors and subsequent adiponectin release, and via the NA transporter OCT3. Gracilis arteries were isolated from control mice. a −PVAT vessels with a section of exogenous PVAT suspended above were stimulated with EFS. The exogenous PVAT was removed and incubated for 30 min with 6-OHDA (2 μM), before returning the PVAT to the organ bath and repeating the stimulus (n = 7, −PVAT vs. exogenous PVAT p < 0.0001****, exogenous PVAT vs. 6-OHDA-treated PVAT p < 0.0001++++, −PVAT vs. 6-OHDA-treated PVAT p > 0.05). b Following control responses to EFS ±PVAT vessels were incubated with SR59230A (SR, 1 μM) for 30 min before repeating the EFS stimulus (n = 8, −PVAT vs. +PVAT p < 0.0001, −PVAT vs. −PVAT & SR p > 0.05, +PVAT vs. +PVAT & SR p < 0.0001****, −PVAT vs. +PVAT & SR p < 0.0001****). c Following control responses to EFS ±PVAT vessels were incubated with CL-316,243 (CL, 10 μM) for 30 min before repeating the EFS stimulus (n = 8, −PVAT vs. +PVAT p < 0.0001****, −PVAT vs. −PVAT & CL p > 0.05, +PVAT vs. +PVAT & CL p < 0.0001****, −PVAT vs. +PVAT & CL p < 0.0001). d −PVAT vessels with a section of exogenous PVAT…

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  Fig. 4. PVAT anticontractile effect is absent in gracilis arteries from Adipo−/− mice. Gracilis arteries from Adipo−/− mice with and without PVAT were subjected to EFS, before incubating with CL-316,243 for 30 min and repeating the stimulus. Data shown are mean ± SEM (n = 8, p > 0.05 all comparisons). PVAT versus. +PVAT vessels were tested using two-way ANOVA. Before and after drugs within the same vessel type, e.g., −PVAT before drug versus. −PVAT after drug were tested using repeated-measures ANOVA. Both followed by Bonferroni post hoc tests.

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  Fig. 5. β3-adrenoceptor function in gracilis PVAT is lost in obesity, and the vasodilator function of adiponectin is lost. a Gracilis arteries from obese mice with and without PVAT were subjected to EFS, before incubating with CL-316,243 for 30 min and repeating the stimulus (n = 7, p > 0.05 all comparisons). b Following the control EFS protocol, PVAT-denuded vessels were allowed 15 min to recover before incubating with recombinant globular mouse adiponectin (5 μg/mL) and repeating the stimulus (n = 4, p > 0.05). Data shown are mean ± SEM (−PVAT vs. +PVAT vessels were tested using two-way ANOVA. Before and after drugs within the same vessel type, e.g., −PVAT before drug vs. −PVAT after drug were tested using repeated-measures ANOVA. Both followed by Bonferroni post hoc tests).

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  Fig. 6. EFS-induced PVAT anticontractile effect is NOS dependent and can be reduced by inhibition of nNOS. Mesenteric (a) and gracilis (b) −PVAT arteries from control mice with a section of exogenous PVAT suspended above were stimulated with EFS. The exogenous PVAT was removed and incubated for 30 min with L-NMMA (100 µM), before returning the PVAT to the organ bath and repeating the stimulus (n = 8 both groups. a −PVAT vs. exogenous PVAT p < 0.01**, exogenous PVAT vs. L-NMMA-treated PVAT p < 0.0001++++, −PVAT vs. L-NMMA-treated PVAT p > 0.05. b −PVAT vs. exogenous PVAT p < 0.0001****, exogenous PVAT vs. L-NMMA-treated PVAT p < 0.0001++++, −PVAT vs. L-NMMA-treated PVAT p > 0.05). Mesenteric (c) and gracilis (d) −PVAT arteries from control mice with a section of exogenous PVAT suspended above were stimulated with EFS. The exogenous PVAT was removed and incubated for 30 min with vinyl-L-NIO (100 nM), before returning the PVAT to the organ bath and repeating the stimulus (n = 8 both groups. c −PVAT vs. exogenous PVAT p < 0.0001, exogenous PVAT vs. vinyl-L-NIO-treated PVAT p < 0.0001****, −PVAT vs. vinyl-L-NIO-treated PVAT p < 0.01**. d −PVAT vs. exogenous PVAT p < 0.0001, exogenous PVAT vs.…

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  Fig. 7. EFS-induced PVAT anticontractile effect is modulated by eNOS and nNOS isoforms. ±PVAT mesenteric resistance arteries from control (a) and eNOS−/− (b) mice were subjected to a NA concentration-response protocol (n = 8 both groups. a −PVAT vs. +PVAT p < 0.0001****. b −PVAT vs. +PVAT p > 0.05). c Mesenteric resistance arteries from eNOS−/− were stimulated with EFS. d −PVAT mesenteric arteries from eNOS−/− mice with a section of exogenous PVAT suspended above were stimulated with EFS. The exogenous PVAT was removed and incubated for 30 min with vinyl-L-NIO (100 nM), before returning the PVAT to the organ bath and repeating the stimulus (n = 8, −PVAT vs. exogenous PVAT p < 0.001***, exogenous PVAT vs. vinyl-L-NIO-treated PVAT p < 0.0001++++, −PVAT vs. vinyl-L-NIO-treated PVAT p > 0.05). Data shown are mean ± SEM (−PVAT vs. +PVAT vessels were tested using two-way ANOVA. Before and after drugs within the same vessel type, e.g., +exogenous PVAT before drug vs. +exogenous PVAT after drug were tested using repeated-measures ANOVA. Both followed by Bonferroni post hoc tests).

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  Fig. 8. Activation of NOS restores PVAT function in obesity in mesenteric arteries but not in the gracilis artery. −PVAT mesenteric (a) and gracilis (b) arteries from obese mice with a section of exogenous PVAT suspended above were stimulated with EFS. The exogenous PVAT was removed and incubated for 30 min with histamine (100 μM), before returning the PVAT to the organ bath and repeating the stimulus (n = 8, a −PVAT vs. exogenous PVAT p > 0.05, exogenous PVAT vs. histamine-treated PVAT p < 0.001***, −PVAT vs. histamine-treated PVAT p < 0.05+. b p > 0.5 all comparisons). Data shown are mean ± SEM (−PVAT vs. +PVAT vessels were tested using two-way ANOVA. Before and after drugs within the same vessel type, e.g., +exogenous PVAT before drug vs. +exogenous PVAT after drug were tested using repeated-measures ANOVA. Both followed by Bonferroni post hoc tests).