Aging induces muscle-specific impairment of endothelium-dependent dilation in skeletal muscle feed arteries

2002 ◽  
Vol 93 (5) ◽  
pp. 1685-1690 ◽  
Author(s):  
Christopher R. Woodman ◽  
Elmer M. Price ◽  
M. Harold Laughlin
Keyword(s):  
Skeletal Muscle ◽  
Mrna Expression ◽  
Vascular Function ◽  
Fischer 344 ◽  
Old Rats ◽  
The Right ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
Feed Arteries ◽  
Skeletal Muscle Feed Arteries

We tested the hypothesis that aging decreases endothelium-dependent vasodilation in feed arteries perfusing rat skeletal muscle. In addition, we tested the hypothesis that attenuated vasodilator responses are associated with decreased endothelial nitric oxide synthase (eNOS) and superoxide dismutase-1 (SOD-1) expression. Soleus feed arteries (SFA) and gastrocnemius feed arteries (GFA) were isolated from young (4 mo) and old (24 mo) male Fischer 344 rats. Feed arteries from the right hindlimb were cannulated with two glass micropipettes for examination of endothelium-dependent [acetylcholine (ACh)] and endothelium-independent [adenosine (Ado) or sodium nitroprusside (SNP)] vasodilator function. Feed arteries from the left hindlimb were frozen and used to assess eNOS and SOD-1 protein and mRNA expression. In SFA, endothelium-dependent dilation to ACh was reduced in old rats (0.9 ± 0.04 vs. 0.8 ± 0.03), whereas dilator responses to Ado and SNP were similar in SFA of young and old rats. In GFA, vasodilator responses to ACh, Ado, and SNP were not altered by age. eNOS and SOD-1 protein expression declined with age in SFA (−71 and −54%, respectively) but not in GFA. eNOS and SOD-1 mRNA expression were not altered by age in SFA or GFA. Collectively, these data indicate aging induces muscle-specific impairment of endothelium-dependent vascular function in SFA.

Shear stress induces eNOS mRNA expression and improves endothelium-dependent dilation in senescent soleus muscle feed arteries

2005 ◽  
Vol 98 (3) ◽  
pp. 940-946 ◽  
Author(s):  
Christopher R. Woodman ◽  
Elmer M. Price ◽  
M. Harold Laughlin
Keyword(s):  
Shear Stress ◽  
Mrna Expression ◽  
Soleus Muscle ◽  
Low Flow ◽  
No Production ◽  
Fischer 344 ◽  
Enos Mrna ◽  
Series Of Experiments ◽  
Endothelial Nitric Oxide ◽  
Feed Arteries

We tested the hypothesis that increased intraluminal shear stress induces endothelial nitric oxide (NO) synthase (eNOS) mRNA expression and improves endothelium-dependent dilation in senescent soleus muscle feed arteries (SFA) by increasing NO production. SFA were isolated from young (4 mo) and old (24 mo) male Fischer 344 rats and cannulated with two resistance-matched glass micropipettes. SFA were exposed to no flow (NF), low flow (LF), intermediate flow (IF), or high flow (HF) for 4 h. Mean intraluminal shear stress ranged from 0 to 82 dyn/cm2. At the end of the 4-h treatment period, eNOS mRNA expression was assessed in each SFA. eNOS mRNA expression was significantly lower in old NF SFA than in young NF SFA. In old SFA, eNOS mRNA expression was induced by IF (+154%) and HF (+136%), resulting in a level of expression that was not different from that of young SFA. In a separate series of experiments, SFA were pretreated with NF or HF for 4 h, and endothelial function was assessed by examining vasodilator responses to ACh. ACh-induced dilation was less in old NF SFA than young NF SFA. Pretreatment with HF improved ACh-induced dilation in old SFA such that the response was similar to that of young SFA. In the presence of Nω-nitro-l-arginine to inhibit NOS, ACh-induced dilation was inhibited in old HF SFA such that the response was no longer greater than that of old NF SFA. These results indicate that increased intraluminal shear stress induces eNOS mRNA expression and improves endothelium-dependent dilation in senescent SFA by increasing NO production.

scholarly journals TRPV1channels in human skeletal muscle feed arteries: implications for vascular function

2017 ◽  
Vol 102 (9) ◽  
pp. 1245-1258 ◽  
Author(s):  
Stephen J. Ives ◽  
Song Young Park ◽  
Oh Sung Kwon ◽  
Jayson R. Gifford ◽  
Robert H. I. Andtbacka ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Vascular Function ◽  
Human Skeletal Muscle ◽  
Feed Arteries ◽  
Skeletal Muscle Feed Arteries

scholarly journals Obesity, type 2 diabetes, and impaired insulin-stimulated blood flow: role of skeletal muscle NO synthase and endothelin-1

2017 ◽  
Vol 122 (1) ◽  
pp. 38-47 ◽  
Author(s):  
Leryn J. Reynolds ◽  
Daniel P. Credeur ◽  
Camila Manrique ◽  
Jaume Padilla ◽  
Paul J. Fadel ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Type 2 Diabetes ◽  
Skeletal Muscle ◽  
Blood Flow ◽  
Vastus Lateralis ◽  
Glucose Disposal ◽  
Endothelin 1 ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Increased endothelin-1 (ET-1) and reduced endothelial nitric oxide phosphorylation (peNOS) are hypothesized to reduce insulin-stimulated blood flow in type 2 diabetes (T2D), but studies examining these links in humans are limited. We sought to assess basal and insulin-stimulated endothelial signaling proteins (ET-1 and peNOS) in skeletal muscle from T2D patients. Ten obese T2D [glucose disposal rate (GDR): 6.6 ± 1.6 mg·kg lean body mass (LBM)−1·min−1] and 11 lean insulin-sensitive subjects (Lean GDR: 12.9 ± 1.2 mg·kg LBM−1·min−1) underwent a hyperinsulinemic-euglycemic clamp with vastus lateralis biopsies taken before and 60 min into the clamp. Basal biopsies were also taken in 11 medication-naïve, obese, non-T2D subjects. ET-1, peNOS (Ser1177), and eNOS protein and mRNA were measured from skeletal muscle samples containing native microvessels. Femoral artery blood flow was assessed by duplex Doppler ultrasound. Insulin-stimulated blood flow was reduced in obese T2D (Lean: +50.7 ± 6.5% baseline, T2D: +20.8 ± 5.2% baseline, P < 0.05). peNOS/eNOS content was higher in Lean under basal conditions and, although not increased by insulin, remained higher in Lean during the insulin clamp than in obese T2D ( P < 0.05). ET-1 mRNA and peptide were 2.25 ± 0.50- and 1.52 ± 0.11-fold higher in obese T2D compared with Lean at baseline, and ET-1 peptide remained 2.02 ± 1.9-fold elevated in obese T2D after insulin infusion ( P < 0.05) but did not increase with insulin in either group ( P > 0.05). Obese non-T2D subjects tended to also display elevated basal ET-1 ( P = 0.06). In summary, higher basal skeletal muscle expression of ET-1 and reduced peNOS/eNOS may contribute to a reduced insulin-stimulated leg blood flow response in obese T2D patients. NEW & NOTEWORTHY Although impairments in endothelial signaling are hypothesized to reduce insulin-stimulated blood flow in type 2 diabetes (T2D), human studies examining these links are limited. We provide the first measures of nitric oxide synthase and endothelin-1 expression from skeletal muscle tissue containing native microvessels in individuals with and without T2D before and during insulin stimulation. Higher basal skeletal muscle expression of endothelin-1 and reduced endothelial nitric oxide phosphorylation (peNOS)/eNOS may contribute to reduced insulin-stimulated blood flow in obese T2D patients.

scholarly journals Potential pitfalls in analyzing structural uncoupling of eNOS: aging is not associated with increased enzyme monomerization

2019 ◽  
Vol 316 (1) ◽  
pp. H80-H88 ◽  
Author(s):  
Fumin Chang ◽  
Sheila Flavahan ◽  
Nicholas A. Flavahan
Keyword(s):  
Nitric Oxide ◽  
Endothelial Dysfunction ◽  
Nitric Oxide Synthase ◽  
Endothelial Nitric Oxide Synthase ◽  
Normal Activity ◽  
Aortic Endothelial Cells ◽  
Relative Expression ◽  
Fischer 344 ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Homodimer formation is essential for the normal activity of endothelial nitric oxide synthase (eNOS). Structural uncoupling of eNOS, with generation of enzyme monomers, is thought to contribute to endothelial dysfunction in several vascular disorders, including aging. However, low-temperature SDS-PAGE of healthy arteries has revealed considerable variation between studies in the relative expression of eNOS dimers and monomers. While assessing structural uncoupling of eNOS in aging arteries, we identified methodological pitfalls that might contribute to such variation. Therefore, using human cultured aortic endothelial cells and aortas from young and aged Fischer-344 rats, we investigated optimal approaches for analyzing the expression of eNOS monomers and dimers. The results demonstrated that published differences in treatment of cell lysates can significantly impact the relative expression of several eNOS species, including denatured monomers, partially folded monomers, dimers, and higher-order oligomers. In aortas, experiments initially confirmed a large increase in eNOS monomers in aging arteries, consistent with structural uncoupling. However, these monomers were actually endogenous IgG, which, under these conditions, has mobility similar to eNOS monomers. Increased IgG levels in aged aortas likely reflect the aging-induced disruption of endothelial junctions and increased arterial penetration of IgG. After removal of the IgG signal, there were low levels of eNOS monomers in young arteries, which were not significantly different in aged arteries. Therefore, structural uncoupling of eNOS is not a prominent feature in young healthy arteries, and the process is not increased by aging. The study also identifies optimal approaches to analyze eNOS dimers and monomers. NEW & NOTEWORTHY Structural uncoupling of endothelial nitric oxide synthase (eNOS) is considered central to endothelial dysfunction. However, reported levels of eNOS dimers and monomers vary widely, even in healthy arteries. We demonstrate that sample processing can alter relative levels of eNOS species. Moreover, endothelial dysfunction in aging aortas results in IgG accumulation, which, because of similar mobility to eNOS monomers, could be misinterpreted as structural uncoupling. Indeed, enzyme monomerization is not prominent in young or aging arteries.

Abstract 17415: Mitochondrial Ca2+/Calmodulin-Dependent Kinase II Inhibition Changes the Calcium Homeostasis in the Endothelium and Decreases the Vascular Relaxation in Mesenteric Arteries

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Celio Damacena De Angelis ◽  
Daniel W Nuno ◽  
Olha Koval ◽  
Kathryn G Lamping ◽  
Isabella M Grumbach
Keyword(s):  
Calcium Release ◽  
Mesenteric Arteries ◽  
Lower Sensitivity ◽  
No Production ◽  
Vascular Relaxation ◽  
Fura 2 ◽  
The Right ◽  
Oxide Synthase ◽  
Mesenteric Resistance Artery ◽  
Endothelial Nitric Oxide

Introduction: The Ca2+/Calmodulin-dependent Kinase II (CaMKII) is present in mitochondria and cytosol. In mitochondria, it regulates the mitochondrial Ca 2+ uptake via the mitochondrial Ca2+ uniporter. Since endothelial nitric oxide synthase activity is regulated by intracellular [Ca2+], we hypothesized that it affects cytosolic Ca2+, NO production and ACh-dependent vasodilation. Hypothesis: Inhibition of mitochondrial CaMKII in endothelium increases the cytosolic [Ca2+], and decreases vasorelaxation by Acetylcholine. Methods: CaMKII in mitochondria was inhibited through expression of the mitochondria-targeted CaMKII inhibitor peptide (mito-CaMKIIN) in a novel transgenic mouse model (endo-mtCaMKIIN) in endothelial cells only or delivered by adenoviral transduction (Ad-mtCaMKIIN) in human Aortic Endothelium cells (HAEC). In HAEC, cytosolic Ca2+ levels (by FURA-2 AM), eNOS activation and NOx levels were measured. Results: The basal Ca2+ levels were higher in the cytosol of mitoCaMKIIN cells (1.08 ± 0.02 Fura-2 ratio normalized by control, p<0.05). Thapsigargin-induced ER Ca 2+ release was significantly higher with mitoCaMKIIN (AUC 0.252 ± 0.027 versus 0.112 ± 0.01275, p<0.05), whereas cytosolic Ca 2+ levels after ACh were reduced (AUC 0.191 ± 0.025 versus 0.435 ± 0.054). Higher levels of phosphorylation of eNOS at Ser1177 and Thr495 sites were seen at baseline. The concentration-response curve of vascular relaxation to acetylcholine and SNP shifted to the right (p<0.05) in mesenteric resistance artery of mitoCaMKIIN mice. Conclusions: The inhibition of mitochondrial CaMKII in the endothelium increases the cytosolic levels, endoplasmic reticulum storage of calcium and eNOS phosphorylation. However, there are lower calcium release and lower sensitivity to acetylcholine and SNP.

EDHF mediates flow-induced dilation in skeletal muscle arterioles of female eNOS-KO mice

2001 ◽  
Vol 280 (6) ◽  
pp. H2462-H2469 ◽  
Author(s):  
An Huang ◽  
Dong Sun ◽  
Mairead A. Carroll ◽  
Houli Jiang ◽  
Carolyn J. Smith ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Skeletal Muscle ◽  
Endothelial Nitric Oxide Synthase ◽  
Hexanoic Acid ◽  
Gracilis Muscle ◽  
Wild Type ◽  
Basal Release ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
Cytochrome P 450

Vasodilation to increases in flow was studied in isolated gracilis muscle arterioles of female endothelial nitric oxide synthase (eNOS)-knockout (KO) and female wild-type (WT) mice. Dilation to flow (0–10 μl/min) was similar in the two groups, yet calculated wall shear stress was significantly greater in arterioles of eNOS-KO than in arterioles of WT mice. Indomethacin, which inhibited flow-induced dilation in vessels of WT mice by ∼40%, did not affect the responses of eNOS-KO mice, whereas miconazole and 6-(2-proparglyoxyphenyl)hexanoic acid (PPOH) abolished the responses. Basal release of epoxyeicosatrienonic acids from arterioles was inhibited by PPOH. Iberiotoxin eliminated flow-induced dilation in arterioles of eNOS-KO mice but had no effect on arterioles of WT mice. In WT mice, neither N ω-nitro-l-arginine methyl ester nor miconazole alone affected flow-induced dilation. Combination of both inhibitors inhibited the responses by ∼50%. 1 H-[1,2,4]oxadiazolo[4,3- a]quinoxalin-1-one (ODQ) alone inhibited flow-induced dilation by ∼49%. ODQ + indomethacin eliminated the responses. Thus, in arterioles of female WT mice, nitric oxide and prostaglandins mediate flow-induced dilation. When eNOS is inhibited, endothelium-derived hyperpolarizing factor substitutes for nitric oxide. In female eNOS-KO mice, metabolites of cytochrome P-450, via activation of large-conductance Ca2+-activated K+ channels of smooth muscle, mediate entirely the arteriolar dilation to flow.

scholarly journals Transcriptome-wide RNA sequencing analysis of rat skeletal muscle feed arteries. I. Impact of obesity

2014 ◽  
Vol 116 (8) ◽  
pp. 1017-1032 ◽  
Author(s):  
Nathan T. Jenkins ◽  
Jaume Padilla ◽  
Pamela K. Thorne ◽  
Jeffrey S. Martin ◽  
R. Scott Rector ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Endothelial Cell ◽  
Rna Sequencing ◽  
Differentially Expressed ◽  
Aortic Endothelial Cell ◽  
Oletf Rats ◽  
Long Evans ◽  
Feed Arteries ◽  
Skeletal Muscle Feed Arteries ◽  
Aortic Endothelial

We employed next-generation RNA sequencing (RNA-Seq) technology to determine the influence of obesity on global gene expression in skeletal muscle feed arteries. Transcriptional profiles of the gastrocnemius and soleus muscle feed arteries (GFA and SFA, respectively) and aortic endothelial cell-enriched samples from obese Otsuka Long-Evans Tokushima Fatty (OLETF) and lean Long-Evans Tokushima Otsuka (LETO) rats were examined. Obesity produced 282 upregulated and 133 downregulated genes in SFA and 163 upregulated and 77 downregulated genes in GFA [false discovery rate (FDR) < 10%] with an overlap of 93 genes between the arteries. In LETO rats, there were 89 upregulated and 114 downregulated genes in the GFA compared with the SFA. There were 244 upregulated and 275 downregulated genes in OLETF rats (FDR < 10%) in the GFA compared with the SFA, with an overlap of 76 differentially expressed genes common to both LETO and OLETF rats in both the GFA and SFA. A total of 396 transcripts were found to be differentially expressed between LETO and OLETF in aortic endothelial cell-enriched samples. Overall, we found 1) the existence of heterogeneity in the transcriptional profile of the SFA and GFA within healthy LETO rats, 2) that this between-vessel heterogeneity was markedly exacerbated in the hyperphagic, obese OLETF rat, and 3) a greater number of genes whose expression was altered by obesity in the SFA compared with the GFA. Also, results indicate that in OLETF rats the GFA takes on a relatively more proatherogenic phenotype compared with the SFA.

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