scholarly journals Circadian Rhythmicity in Cerebral Microvascular Tone Influences Subarachnoid Hemorrhage–Induced Injury

Stroke ◽  
2021 ◽  
Author(s):  
Darcy Lidington ◽  
Hoyee Wan ◽  
Danny D. Dinh ◽  
Chloe Ng ◽  
Steffen-Sebastian Bolz
Keyword(s):  
Smooth Muscle ◽  
Subarachnoid Hemorrhage ◽  
Circadian Rhythms ◽  
Cerebral Arteries ◽  
Circadian Variation ◽  
Neurological Injury ◽  
Myogenic Tone ◽  
Resistance Arteries

Background and Purpose: Circadian rhythms influence the extent of brain injury following subarachnoid hemorrhage (SAH), but the mechanism is unknown. We hypothesized that cerebrovascular myogenic reactivity is rhythmic and explains the circadian variation in SAH-induced injury. Methods: SAH was modeled in mice with prechiasmatic blood injection. Inducible, smooth muscle cell–specific Bmal1 (brain and muscle aryl hydrocarbon receptor nuclear translocator-like protein 1) gene deletion (smooth muscle–specific Bmal1 1 knockout [sm-Bmal1 KO]) disrupted circadian rhythms within the cerebral microcirculation. Olfactory cerebral resistance arteries were functionally assessed by pressure myography in vitro; these functional assessments were related to polymerase chain reaction/Western blot data, brain histology (Fluoro-Jade/activated caspase-3), and neurobehavioral assessments (modified Garcia scores). Results: Cerebrovascular myogenic vasoconstriction is rhythmic, with a peak and trough at Zeitgeber times 23 and 11 (ZT23 and ZT11), respectively. Histological and neurobehavioral assessments demonstrate that higher injury levels occur when SAH is induced at ZT23, compared with ZT11. In sm-Bmal1 KO mice, myogenic reactivity is not rhythmic. Interestingly, myogenic tone is higher at ZT11 versus ZT23 in sm-Bmal1 KO mice; accordingly, SAH-induced injury in sm-Bmal1 KO mice is more severe when SAH is induced at ZT11 compared to ZT23. We examined several myogenic signaling components and found that CFTR (cystic fibrosis transmembrane conductance regulator) expression is rhythmic in cerebral arteries. Pharmacologically stabilizing CFTR expression in vivo (3 mg/kg lumacaftor for 2 days) eliminates the rhythmicity in myogenic reactivity and abolishes the circadian variation in SAH-induced neurological injury. Conclusions: Cerebrovascular myogenic reactivity is rhythmic. The level of myogenic tone at the time of SAH ictus is a key factor influencing the extent of injury. Circadian oscillations in cerebrovascular CFTR expression appear to underlie the cerebrovascular myogenic reactivity rhythm.

Stretch-dependent (myogenic) tone in rabbit ear resistance arteries

1986 ◽  
Vol 250 (1) ◽  
pp. H87-H95 ◽  
Author(s):  
J. J. Hwa ◽  
J. A. Bevan
Keyword(s):  
Smooth Muscle ◽  
Vascular Tone ◽  
Mechanical Stretch ◽  
Myogenic Tone ◽  
Resistance Arteries ◽  
Physiological Regulation ◽  
Rabbit Ear ◽  
Arterial Tone

Rabbit ear resistance arteries are vessels with three to six layers of smooth muscle cells and an unstretched lumen diameter of 75-150 micron. Ring segments of these arteries, in response to mechanical stretch in vitro, developed a maintained tonic contraction. The stretch-dependent contraction achieved a plateau within 10-30 min. Smooth muscle relaxants, such as NaNO2 and papaverine, substitution of extracellular Ca2+ by subthreshold Ca2+ (25 microM), or exposure to the Ca2+ influx antagonist Mn2+ abolished the stretch-dependent tone. The extent of the tone was dependent on the level of the applied stretch and the extracellular Ca2+ concentration ( [Ca2+]o). The maximal tone developed at optimal stretch, and [Ca2+]o in the bath solution was 18.1 +/- 4.6% of the maximal contraction of the vessel to histamine. This level of tone is comparable to neurogenic tone developed in response to nerve stimulation within the physiological frequency range. The stretch-dependent tone is considered probably myogenic in origin, since it was present in arterial segments that had been chronically denervated by surgical sympathectomy, mechanically deprived of the endothelium, and multireceptor blocked (phenoxybenzamine, 10(-6) M). Our findings suggest first that the stretch-dependent tone is myogenic and may be similar to basal vascular tone arising from the stretch of arterial pressure and its changes in vivo. Second, the magnitude of myogenic tone is a function of the applied stretch and the [Ca2+]o. Finally, myogenic tone is important in the physiological regulation of arterial tone in the rabbit ear resistance arteries.

Myogenic tone, reactivity, and forced dilatation: a three-phase model of in vitro arterial myogenic behavior

2002 ◽  
Vol 283 (6) ◽  
pp. H2260-H2267 ◽  
Author(s):  
George Osol ◽  
Johan Fredrik Brekke ◽  
Keara McElroy-Yaggy ◽  
Natalia I. Gokina
Keyword(s):  
Cerebral Arteries ◽  
Peripheral Resistance ◽  
Force Production ◽  
Cytosolic Calcium ◽  
Myogenic Tone ◽  
Wall Tension ◽  
Resistance Arteries ◽  
Cellular Mechanisms ◽  
Initial Development

Myogenic behavior, prevalent in resistance arteries and arterioles, involves arterial constriction in response to intravascular pressure. This process is often studied in vitro by using cannulated, pressurized arterial segments from different regional circulations. We propose a comprehensive model for myogenicity that consists of three interrelated but dissociable phases: 1) the initial development of myogenic tone (MT), 2) myogenic reactivity to subsequent changes in pressure (MR), and 3) forced dilatation at high transmural pressures (FD). The three phases span the physiological range of transmural pressures (e.g., MT, 40–60 mmHg; MR, 60–140 mmHg; FD, >140 mmHg in cerebral arteries) and are characterized by distinct changes in cytosolic calcium ([Ca2+]i), which do not parallel arterial diameter or wall tension, and therefore suggest the existence of additional regulatory mechanisms. Specifically, the development of MT is accompanied by a substantial (200%) elevation in [Ca2+]i and a reduction in lumen diameter and wall tension, whereas MR is associated with relatively small [Ca2+]i increments (<20% over the entire pressure range) despite considerable increases in wall tension and force production but little or no change in diameter. FD is characterized by a significant additional elevation in [Ca2+]i (>50%), complete loss of force production, and a rapid increase in wall tension. The utility of this model is that it provides a framework for comparing myogenic behavior of vessels of different size and anatomic origin and for investigating the underlying cellular mechanisms that govern vascular smooth muscle mechanotransduction and contribute to the regulation of peripheral resistance.

Effect of Propofol on Norepinephrine-induced Increases in [Ca2+](i) and Force in Smooth Muscle of the Rabbit Mesenteric Resistance Artery 

1998 ◽  
Vol 88 (6) ◽  
pp. 1566-1578 ◽  
Author(s):  
Nami Imura ◽  
Yoshihisa Shiraishi ◽  
Hirotada Katsuya ◽  
Takeo Itoh
Keyword(s):  
Smooth Muscle ◽  
Isometric Force ◽  
Resistance Artery ◽  
Resistance Arteries ◽  
High K ◽  
Small Resistance ◽  
Vasodilating Activity ◽  
Mesenteric Resistance Artery

Background Propofol (2,6-diisopropylphenol) possesses vasodilating activity in vivo and in vitro. The propofol-induced relaxation of agonist-induced contractions in small resistance arteries has not been clarified. Methods The effect of propofol was examined on the contractions induced by norepinephrine and high K+ in endothelium-denuded rabbit mesenteric resistance artery in vitro. The effects of propofol on the [Ca2+]i mobilization induced by norepinephrine and high K+ were studied by simultaneous measurement of [Ca2+]i using Fura 2 and isometric force in ryanodine-treated strips. Results Propofol attenuated the contractions induced by high K+ and norepinephrine, the effect being greater on the high K+-induced contraction than on the norepinephrine-induced contraction. In Ca2+-free solution, norepinephrine produced a transient contraction resulting from the release of Ca2+ from storage sites that propofol attenuated. In ryanodine-treated strips, propofol increased the resting [Ca2+]i but attenuated the increases in [Ca2+]i and force induced by both high K+ and norepinephrine. In the presence of nicardipine, propofol had no inhibitory action on the residual norepinephrine-induced [Ca2+]i increase, whereas it still modestly increased resting [Ca2+]i, as in the absence of nicardipine. Conclusions In smooth muscle of the rabbit mesenteric resistance artery, propofol attenuates norepinephrine-induced contractions due to an inhibition both of Ca2+ release and of Ca2+ influx through L-type Ca2+ channels. Propofol also increased resting [Ca2+]i, possibly as a result of an inhibition of [Ca2+]i removal mechanisms. These results may explain in part the variety of actions seen with propofol in various types of vascular smooth muscle.

Enhanced myogenic tone in cerebral arteries from a rabbit model of subarachnoid hemorrhage

2002 ◽  
Vol 283 (6) ◽  
pp. H2217-H2225 ◽  
Author(s):  
Masanori Ishiguro ◽  
Corey B. Puryear ◽  
Erica Bisson ◽  
Christine M. Saundry ◽  
David J. Nathan ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Cerebral Artery ◽  
Cerebral Arteries ◽  
Rabbit Model ◽  
Small Diameter ◽  
Myogenic Tone ◽  
The Impact ◽  
Intravascular Pressure

Cerebral artery vasospasm is a major cause of death and disability in patients experiencing subarachnoid hemorrhage (SAH). Currently, little is known regarding the impact of SAH on small diameter (100–200 μm) cerebral arteries, which play an important role in the autoregulation of cerebral blood flow. With the use of a rabbit SAH model and in vitro video microscopy, cerebral artery diameter was measured in response to elevations in intravascular pressure. Cerebral arteries from SAH animals constricted more (∼twofold) to pressure within the physiological range of 60–100 mmHg compared with control or sham-operated animals. Pressure-induced constriction (myogenic tone) was also enhanced in arteries from control animals organ cultured in the presence of oxyhemoglobin, an effect independent of the vascular endothelium or nitric oxide synthesis. Finally, arteries from both control and SAH animals dilated as intravascular pressure was elevated above 140 mmHg. This study provides evidence for a role of oxyhemoglobin in impaired autoregulation (i.e., enhanced myogenic tone) in small diameter cerebral arteries during SAH. Furthermore, therapeutic strategies that improve clinical outcome in SAH patients (e.g., supraphysiological intravascular pressure) are effective in dilating small diameter cerebral arteries isolated from SAH animals.

Contrasting effects of simulated microgravity with and without daily −Gx gravitation on structure and function of cerebral and mesenteric small arteries in rats

2009 ◽  
Vol 107 (6) ◽  
pp. 1710-1721 ◽  
Author(s):  
Le-Jian Lin ◽  
Fang Gao ◽  
Yun-Gang Bai ◽  
Jun-Xiang Bao ◽  
Xiao-Feng Huang ◽  
...  
Keyword(s):  
Structural Changes ◽  
Cerebral Arteries ◽  
Myogenic Tone ◽  
Resistance Arteries ◽  
Cross Sectional ◽  
Small Arteries ◽  
Functional Studies ◽  
Cell Layers ◽  
And Function

This study was designed to test the hypothesis that a 28-day tail suspension (SUS) could induce hypertrophy and enhanced myogenic and vasoconstrictor reactivity in middle cerebral arteries (MCAs), whereas atrophy and decreased myogenic and vasoconstrictor responses in mesenteric third-order arterioles (MSAs). Also, in addition to the functional enhancement in MCAs, structural changes in both kinds of arteries and functional decrement in MSAs could all be prevented by the intervention of daily 1-h dorsoventral (−Gx) gravitation by restoring to standing posture. To test this hypothesis, vessel diameters to pressure alterations and nonreceptor- and receptor-mediated agonists were determined using a pressure arteriograph with a procedure to measure in vivo length and decrease hysteresis of vessel segments and longitudinal middlemost sections of vessels fixed at maximally dilated state were examined using electron microscopy and histomorphometry. Functional studies showed that 28-day tail-suspended, head-down tilt (SUS) resulted in enhanced and decreased myogenic tone and vasoconstrictor responses, respectively, in MCAs and MSAs. Histomorphometric data revealed that SUS-induced hypertrophic changes in MCAs characterized by increases in thickness (T) and cross-sectional area (CSA) of the media and the number of vascular smooth-muscle-cell layers (NCL), whereas in MSAs, it induced decreases in medial CSA and T and NCL. Daily 1-h −Gx over 28 days can fully prevent these differential structural changes in both kinds of small arteries and the functional decrement in MSAs, but not the augmented myogenic tone and increased vasoreactivity in the MCAs. These findings have revealed special features of small resistance arteries during adaptation to microgravity with and without gravity-based countermeasure.

Abstract P183: Chemokine-like Receptor 1 Mediates the Vasoconstrictor Actions of Chemerin in vitro and in vivo

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Amanda Kennedy ◽  
Peiran Yang ◽  
Cai Read ◽  
Rhoda Kuc ◽  
Janet Maguire ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Smooth Muscle ◽  
Therapeutic Potential ◽  
Plasma Concentrations ◽  
Resistance Arteries ◽  
Resistance Vessels ◽  
Increased Risk ◽  
First Time

Hypertensive patients have significantly higher plasma concentrations of the adipokine chemerin compared with healthy controls, and levels of chemerin positively correlate with systolic and diastolic blood pressure. Chemerin activates chemokine-like receptor 1 (CMKLR1 or ChemR23) but it also activates the ‘orphan’ G protein-coupled receptor 1 (GPR1) which has been linked with hypertension. It is therefore crucial to determine whether one or both of these receptors mediate the constrictor actions of chemerin in the vasculature in order to identify a potential new therapeutic target for the treatment of hypertension. Using immunohistochemistry and molecular biology, we localized chemerin to the endothelium, smooth muscle and adventitia, and CMKLR1 and GPR1 to the smooth muscle in human conduit and resistance vessels. Chemerin activated β-arrestin via heterologously expressed receptors GPR1 (pD 2 =9.30±0.05) and CMKLR1 (pD 2 =9.23±0.03) with comparable potency. CCX832, a small molecule antagonist, was fully characterized as highly selective for CMKLR1, with no effect on GPR1 in binding or cell-based functional assays. The C-terminal fragment of chemerin, C9 (chemerin149-157) contracted human saphenous vein (pD 2 =7.30±0.31) and resistance arteries (pD 2 =6.23±0.16), and caused a significant increase in blood pressure in rats in vivo (0.2 μmol, 9.1±1.0 mmHg). These actions were blocked by CCX832, confirming for the first time that a single chemerin receptor, CMKLR1, mediates the constrictor response in humans and in vivo. Our data suggest that chemerin activation of CMKLR1 may contribute to elevated blood pressure; this in combination with the known roles of chemerin in metabolic syndrome and diabetes, could lead to increased risk of cardiovascular disease. This study provides proof of principle that the therapeutic potential of selective CMKLR1 antagonists should be explored.

scholarly journals Vascular circadian rhythms in a mouse vascular smooth muscle cell line (Movas-1)

2008 ◽  
Vol 295 (5) ◽  
pp. R1529-R1538 ◽  
Author(s):  
Jennifer A. Chalmers ◽  
Tami A. Martino ◽  
Nazneen Tata ◽  
Martin R. Ralph ◽  
Michael J. Sole ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Circadian Rhythms ◽  
Vascular Smooth Muscle ◽  
Circadian Clock ◽  
Smooth Muscle Cell ◽  
Cell Line ◽  
Cell Model ◽  
Muscle Cell Line

The circadian system in mammals is a hierarchy of oscillators throughout the organism that are coordinated by the circadian clock in the hypothalamic suprachiasmatic nucleus. Peripheral clocks act to integrate time-of-day information from neural or hormonal signals, regulating gene expression, and, subsequently, organ physiology. However, the mechanisms by which the central clock communicates with peripheral oscillators are not understood and are likely tissue specific. In this study, we establish a mouse vascular cell model suitable for investigations of these mechanisms at a molecular level. Using the immortalized vascular smooth muscle cell line Movas-1, we determined that these cells express the circadian clock machinery with robust rhythms in mRNA expression over a 36-h period after serum shock synchronization. Furthermore, norepinephrine and forskolin were able to synchronize circadian rhythms in bmal1. With synchronization, we observed cycling of specific genes, including the tissue inhibitor of metalloproteinase 1 and 3 ( timp1, timp3), collagen 3a1 ( col3a1), transgelin 1 ( sm22α), and calponin 1 ( cnn1). Diurnal expression of these genes was also found in vivo in mouse aortic tissue, using microarray and real-time RT-PCR analysis. Both of these revealed ultradian rhythms in genes similar to the cycling observed in Movas-1 in vitro. These findings highlight the cyclical nature of structurally important genes in the vasculature that is similar both in vivo and in vitro. This study establishes the Movas-1 cells as a novel cell model from which to further investigate the molecular mechanisms of clock regulation in the vasculature.

Smooth Muscle-Derived Nitric Oxide is Elevated in Isolated Forearm Veins in Human Alcoholic Cirrhosis

1996 ◽  
Vol 91 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Jeremy Ryan ◽  
Garry Jennings ◽  
Frank Dudley ◽  
Jaye Chin-Dusting
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Alcoholic Cirrhosis ◽  
Resistance Arteries ◽  
Nitric Oxide Synthase Inhibitor ◽  
Control Subjects ◽  
Synthase Inhibitor

1. Cirrhosis is often complicated by disturbances in the systemic circulation. We have previously demonstrated decreased vascular responses to vasoconstrictors in forearm resistance arteries in subjects with alcoholic cirrhosis. In the current study we investigate the role of the potent endogenous vasodilator nitric oxide in the peripheral circulation of these patients. 2. Ten patients with alcoholic cirrhosis (Pugh grade A) and 10 age-matched control subjects were studied. The effect of blockade of nitric oxide synthesis was studied both in vivo in forearm resistance arteries using forearm venous occlusion plethysmography and in vitro in veins isolated from the forearm. The role of endothelium-derived nitric oxide was studied in vivo using the endothelium-dependent vasodilator acetylcholine. 3. Mean arterial pressure and forearm basal flow in vivo were similar in the two groups. The constrictor response (percentage decrease in forearm blood flow) to noradrenaline (100 ng/min) was 26% smaller in patients with cirrhosis (31.65 ± 2.64%) than in control subjects (42.75 ± 3.87%, P = 0.037). Constrictor responses to the nitric oxide synthase inhibitor NG-monomethyl-l-arginine were not different in the two groups. Dilator responses to acetylcholine were significantly attenuated in cirrhotic patients compared with control subjects. 4. To investigate the role of smooth muscle-derived nitric oxide in vitro, all veins were stripped of their endothelium. Responses to noradrenaline were significantly diminished in veins isolated from patients with cirrhosis compared with control subjects. Incubation with the nitric oxide synthase inhibitor Nω-nitro-l-arginine had no effect on responses to noradrenaline in veins from control subjects but significantly enhanced the maximal response to noradrenaline by 23.95% (range 3.77–100%, P = 0.043) in veins from patients with cirrhosis. 5. Responses to noradrenaline were attenuated in vivo in forearm resistance arteries in patients with alcoholic cirrhosis. This impairment was also apparent in forearm isolated veins, stripped of the endothelium. Our data exclude a major role for endothelium-derived nitric oxide but highlight a possible role for smooth muscle-derived nitric oxide.

scholarly journals TRPV1 in arteries enables a rapid myogenic tone

2021 ◽  
Author(s):  
Thieu X Phan ◽  
Hoai T Ton ◽  
Hajnalka Gulyas ◽  
Robert Porszasz ◽  
Attila Toth ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Skeletal Muscle ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Critical Role ◽  
Myogenic Tone ◽  
Dynamic Regulation ◽  
Membrane Stretch

Arterioles maintain blow flow by adjusting their diameter in response to changes in local blood pressure. In this process called the myogenic response, a vascular smooth muscle mechanosensor controls tone predominantly through altering the membrane potential. In general, myogenic responses occur slowly, reaching a plateau in minutes. In the heart and skeletal muscle, however, myogenic tone is rapid; activation occurs in tens of seconds and arterial constrictions or raised extravascular pressure as brief as 100 ms remove tone. Previously, we identified extensive expression of TRPV1 in the smooth muscle of arterioles supplying skeletal muscle, heart and the adipose. Here, we reveal a critical role for TRPV1 in the myogenic tone of these tissues. TRPV1 antagonists dilated skeletal muscle arterioles in vitro and in vivo , increased coronary flow in isolated hearts, and transiently decreased blood pressure. All of these effects of TRPV1 antagonists were abolished by genetic disruption of TRPV1. Stretch of isolated vascular smooth muscle cells, or raised intravascular pressure in arteries (with or without endothelium), triggered Ca2+ signaling and vasoconstriction. The majority of these stretch-responses were TRPV1-mediated, with the remaining tone being inhibited by the TRPM4 antagonist, 9-phenantrol. Notably, tone developed more quickly in arteries from wild-type compared with TRPV1-null mice. Furthermore, the rapid vasodilation following brief constriction of arterioles was also dependent on TRPV1, consistent with a rapid deactivation or inactivation of TRPV1. Pharmacologic experiments revealed that membrane stretch activates a phospholipase C/protein kinase C signaling pathway to activate TRPV1, and in turn, L-type Ca2+ channels. These results suggest a critical role, for TRPV1 in the dynamic regulation of myogenic tone and blood flow in the heart and skeletal muscle.

scholarly journals Erythrocyte Extracts Enhance Neurogenic Vasoconstriction of Dog Cerebral Arteries in vitro

1984 ◽  
Vol 4 (3) ◽  
pp. 474-476 ◽  
Author(s):  
Tony J.-F. Lee ◽  
Michael P. McIlhany ◽  
Susan Sarwinski
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Blood Vessels ◽  
Cerebral Vasospasm ◽  
Cerebral Arteries ◽  
Cerebral Blood Vessels ◽  
Neurogenic Vasoconstriction ◽  
To Receive ◽  
Neurogenic Vasodilation

Cerebral blood vessels of the dog have been shown to receive vasodilator and constrictor nerves. In isolated ring arterial preparations, neurogenic vasodilation was blocked while neurogenic vasoconstriction was potentiated by hemolysates isolated from hemolyzed erythrocytes. These results suggest that an overall increase in cerebral neurogenic vasoconstriction may occur in vivo following subarachnoid hemorrhage. The significance of this finding in the pathogenesis of cerebral vasospasm is discussed.

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