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Muscle contraction induced arterial shear stress increases endothelial nitric oxide synthase phosphorylation in humans
- Source :
- American Journal of Physiology-Heart and Circulatory Physiology. 313:H854-H859
- Publication Year :
- 2017
- Publisher :
- American Physiological Society, 2017.
-
Abstract
- We determined if local increases in brachial artery shear during repetitive muscle contractions induce changes in protein expression of endothelial nitric oxide synthase (eNOS) and/or phosphorylated (p-)eNOS at Ser1177, the primary activation site on eNOS, in endothelial cells (ECs) of humans. Seven young male subjects (25 ± 1 yr) performed 20 separate bouts (3 min each) of rhythmic forearm exercise at 20% of maximum over a 2-h period. Each bout of exercise was separated by 3 min of rest. An additional six male subjects (24 ± 1 yr) served as time controls (no exercise). ECs were freshly isolated from the brachial artery using sterile J-wires through an arterial catheter at baseline and again after the 2-h exercise or time control period. Expression of eNOS or p-eNOS Ser1177 in ECs was determined via immunofluorescence. Brachial artery mean shear rate was elevated compared with baseline and the time control group throughout the 2-h exercise protocol ( P < 0.001). p-eNOS Ser1177 expression was increased 57% in ECs in the exercise group [0.06 ± 0.01 vs. 0.10 ± 0.02 arbitrary units (au), P = 0.02] but not in the time control group (0.08 ± 0.01 vs. 0.07 ± 0.01 au, P = 0.72). In contrast, total eNOS expression did not change in either the exercise (0.13 ± 0.04 vs. 0.12 ± 0.03 au) or time control (0.12 ± 0.03 vs. 0.11 ± 0.03 au) group ( P > 0.05 for both). Our novel results suggest that elevations in brachial artery shear increase eNOS Ser1177 phosphorylation in the absence of changes in total eNOS in ECs of young healthy male subjects, suggesting that this model is sufficient to alter posttranslational modification of eNOS activity in vivo in humans. NEW & NOTEWORTHY Elevations in brachial artery shear in response to forearm exercise increased endothelial nitric oxide synthase Ser1177 phosphorylation in brachial artery endothelial cells of healthy humans. Our present study provides the first evidence in humans that muscle contraction-induced increases in conduit arterial shear lead to in vivo posttranslational modification of endothelial nitric oxide synthase activity in endothelial cells.
- Subjects :
- Adult
Male
0301 basic medicine
medicine.medical_specialty
Brachial Artery
Nitric Oxide Synthase Type III
Physiology
030204 cardiovascular system & hematology
Young Adult
03 medical and health sciences
0302 clinical medicine
Forearm
Stress, Physiological
Physiology (medical)
Internal medicine
medicine.artery
medicine
Shear stress
Humans
Phosphorylation
Brachial artery
Exercise
Rapid Report
Endothelial nitric oxide synthase
business.industry
Arteries
Anatomy
body regions
030104 developmental biology
medicine.anatomical_structure
Endocrinology
Shear (geology)
Regional Blood Flow
cardiovascular system
medicine.symptom
Cardiology and Cardiovascular Medicine
business
Muscle Contraction
Muscle contraction
Subjects
Details
- ISSN :
- 15221539 and 03636135
- Volume :
- 313
- Database :
- OpenAIRE
- Journal :
- American Journal of Physiology-Heart and Circulatory Physiology
- Accession number :
- edsair.doi.dedup.....fe0e12b5498b0553fd6b5cabeb8335b8