scholarly journals Vascular Smooth Muscle Contractile Function Declines With Age in Skeletal Muscle Feed Arteries

2018 ◽  
Vol 9 ◽  
Author(s):  
John W. Seawright ◽  
Harini Sreenivasappa ◽  
Holly C. Gibbs ◽  
Samuel Padgham ◽  
Song Y. Shin ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Contractile Function ◽  
Feed Arteries ◽  
Muscle Contractile ◽  
Skeletal Muscle Feed Arteries

Vascular Smooth Muscle Contractile Function Is Impaired during Early and Late Stages of Sepsis

1994 ◽  
Vol 56 (6) ◽  
pp. 556-561 ◽  
Author(s):  
Samuel H. Wurster ◽  
Ping Wang ◽  
Richard E. Dean ◽  
Irshad H. Chaudry
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Contractile Function ◽  
Late Stages ◽  
Muscle Contractile

scholarly journals Fundamental Roles of Axial Stretch in Isometric and Isobaric Evaluations of Vascular Contractility

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Alexander W. Caulk ◽  
Jay D. Humphrey ◽  
Sae-Il Murtada
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Muscle Function ◽  
Contractile Function ◽  
Contractile Activity ◽  
Comparison Of Methods ◽  
Axial Stretch ◽  
Smooth Muscle Function ◽  
In Vivo Loading

Vascular smooth muscle cells (VSMCs) can regulate arterial mechanics via contractile activity in response to changing mechanical and chemical signals. Contractility is traditionally evaluated via uniaxial isometric testing of isolated rings despite the in vivo environment being very different. Most blood vessels maintain a locally preferred value of in vivo axial stretch while subjected to changes in distending pressure, but both of these phenomena are obscured in uniaxial isometric testing. Few studies have rigorously analyzed the role of in vivo loading conditions in smooth muscle function. Thus, we evaluated effects of uniaxial versus biaxial deformations on smooth muscle contractility by stimulating two regions of the mouse aorta with different vasoconstrictors using one of three testing protocols: (i) uniaxial isometric testing, (ii) biaxial isometric testing, and (iii) axially isometric plus isobaric testing. Comparison of methods (i) and (ii) revealed increased sensitivity and contractile capacity to potassium chloride and phenylephrine (PE) with biaxial isometric testing, and comparison of methods (ii) and (iii) revealed a further increase in contractile capacity with isometric plus isobaric testing. Importantly, regional differences in estimated in vivo axial stretch suggest locally distinct optimal biaxial configurations for achieving maximal smooth muscle contraction, which can only be revealed with biaxial testing. Such differences highlight the importance of considering in vivo loading and geometric configurations when evaluating smooth muscle function. Given the physiologic relevance of axial extension and luminal pressurization, we submit that, when possible, axially isometric plus isobaric testing should be employed to evaluate vascular smooth muscle contractile function.

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.

scholarly journals Dysfunction of muscle contraction with impaired intracellular Ca2+ handling in skeletal muscle and the effect of exercise training in male db/db mice

2019 ◽  
Vol 126 (1) ◽  
pp. 170-182 ◽  
Author(s):  
Hiroaki Eshima ◽  
Yoshifumi Tamura ◽  
Saori Kakehi ◽  
Kyoko Nakamura ◽  
Nagomi Kurebayashi ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Skeletal Muscle ◽  
Exercise Training ◽  
Muscle Contraction ◽  
Contractile Function ◽  
Contractile Force ◽  
Contractile Dysfunction ◽  
Muscle Contractile ◽  
Type 2 Diabetic

Type 2 diabetes is characterized by reduced contractile force production and increased fatigability of skeletal muscle. While the maintenance of Ca2+ homeostasis during muscle contraction is a requisite for optimal contractile function, the mechanisms underlying muscle contractile dysfunction in type 2 diabetes are unclear. Here, we investigated skeletal muscle contractile force and Ca2+ flux during contraction and pharmacological stimulation in type 2 diabetic model mice ( db/db mice). Furthermore, we investigated the effect of treadmill exercise training on muscle contractile function. In male db/db mice, muscle contractile force and peak Ca2+ levels were both lower during tetanic stimulation of the fast-twitch muscles, while Ca2+ accumulation was higher after stimulation compared with control mice. While 6 wk of exercise training did not improve glucose tolerance, exercise did improve muscle contractile dysfunction, peak Ca2+ levels, and Ca2+ accumulation following stimulation in male db/db mice. These data suggest that dysfunctional Ca2+ flux may contribute to skeletal muscle contractile dysfunction in type 2 diabetes and that exercise training may be a promising therapeutic approach for dysfunctional skeletal muscle contraction. NEW & NOTEWORTHY The purpose of this study was to examine muscle contractile function and Ca2+ regulation as well as the effect of exercise training in skeletal muscle in obese diabetic mice ( db/db). We observed impairment of muscle contractile force and Ca2+ regulation in a male type 2 diabetic animal model. These dysfunctions in muscle were improved by 6 wk of exercise training.

Subacute Sepsis Impairs Vascular Smooth Muscle Contractile Machinery and Alters Vasoconstrictor and Dilator Mechanisms

1999 ◽  
Vol 83 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Shaun A. Price ◽  
David A. Spain ◽  
Mark A. Wilson ◽  
Patrick D. Harris ◽  
R.Neal Garrison
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Muscle Contractile

The role of globins in cardiovascular physiology

2021 ◽  
Author(s):  
T.C. Steven Keller ◽  
Christophe Lechauve ◽  
Alexander S Keller ◽  
Steven Brooks ◽  
Mitchell J Weiss ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Central Nervous System ◽  
Nervous System ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Cell Types ◽  
Specific Cell ◽  
In Cells

Globin proteins exist in every cell type of the vasculature, from erythrocytes to endothelial cells, vascular smooth muscle cells, and peripheral nerve cells. Many globin subtypes are also expressed in muscle tissues (including cardiac and skeletal muscle), in other organ-specific cell types, and in cells of the central nervous system. The ability of each of these globins to interact with molecular oxygen (O2) and nitric oxide (NO) is preserved across these contexts. Endothelial α-globin is an example of extra-erythrocytic globin expression. Other globins, including myoglobin, cytoglobin, and neuroglobin are observed in other vascular tissues. Myoglobin is observed primarily in skeletal muscle and smooth muscle cells surrounding the aorta or other large arteries. Cytoglobin is found in vascular smooth muscle but can also be expressed in non-vascular cell types, especially in oxidative stress conditions after ischemic insult. Neuroglobin was first observed in neuronal cells, and its expression appears to be restricted mainly to the central and peripheral nervous systems. Brain and central nervous system neurons expressing neuroglobin are positioned close to many arteries within the brain parenchyma and can control smooth muscle contraction and, thus, tissue perfusion and vascular reactivity. Overall, reactions between NO and globin heme-iron contribute to vascular homeostasis by regulating vasodilatory NO signals and scaveging reactive species in cells of the mammalian vascular system. Here, we discuss how globin proteins affect vascular physiology with a focus on NO biology, and offer perspectives for future study of these functions.

Abstract 1102: Cardiac-Specific Myosin Light Chain Kinase (MLCK), a Third Member of MLCK Family, Potentiates Sarcomere Formation and Cardiac Contraction

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Jason Y Chan ◽  
Morihiko Takeda ◽  
Laura E Briggs ◽  
Jonathan T Lu ◽  
Nobuo Horikoshi ◽  
...  
Keyword(s):  
Heart Failure ◽  
Skeletal Muscle ◽  
Smooth Muscle ◽  
Cardiac Hypertrophy ◽  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Contractile Function ◽  
Severe Heart Failure ◽  
Cardiac Contraction

Background: Two myosin light chain kinase (MLCK) proteins, skeletal (encoded by mylk2 gene) and smooth muscle MLCK (encoded by mylk1 gene) have been shown to be expressed in mammals. Human mylk2 has been mapped as a disease locus for familial cardiac hypertrophy (OMIM 606566 ), suggesting that abnormal function of skeletal MLCK stimulates cardiac hypertrophy. While phosphorylation of the putative substrate of skeletal MLCK, myosin light chain 2 (MLC2), is recognized as a key regulator of cardiac contraction, the abundance of skeletal MLCK in the heart is controversial, suggesting the existence of an additional MLCK that is preferentially expressed in cardiac muscle. Methods and Results: We characterized a new kinase named cardiac MLCK that is encoded by a gene homologous to mylk1 and 2 and is specifically expressed in the heart in both atrium and ventricle. Expression of cardiac MLCK was highly regulated by the cardiac homeobox transcription factor, Nkx2.5, in neonatal cardiomyocytes. The overall structure of cardiac MLCK protein is conserved with skeletal and smooth muscle MLCK including putative catalytic and adjacent Ca2+/calmodulin binding domains at the carboxyl-terminus. The amino-terminus is unique without significant homology to other known proteins. Cardiac MLCK phosphorylated MLC2v with a catalytic value of Km=4.3 micro M (Lineweaver-Burk analysis) indicating high affinity of cardiac MLCK to MLC2v, similar to the affinity of skeletal muscle MLCK to skeletal muscle MLC2 and smooth muscle MLCK to smooth muscle MLC2. Adenoviral-mediated overexpression of cardiac MLCK and knockdown of cardiac MLCK using RNAi in cultured cardiomyocytes revealed that cardiac MLCK regulates MLC2v phosphorylation, sarcomere organization and cardiac myocyte contraction. Expression of cardiac MLCK protein was significantly decreased in severe heart failure in vivo (post-myocardial infarction heart failure mouse model). Conclusion: Cardiac MLCK is a new key regulator of cardiac contraction and sarcomere organization. Reduction of cardiac MLCK function leading to decreased phosphorylation of MLC2v may contribute to compromised contractile function in the failing heart.

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