-
Journal of the American Heart... Feb 2022
Topics: Muscle, Smooth, Vascular; Receptor, Angiotensin, Type 1; Vasoconstriction
PubMed: 35156384
DOI: 10.1161/JAHA.121.024740 -
Journal of Applied Physiology... Nov 2019Although respiratory sinus arrhythmia and blood pressure variability have been investigated extensively, there have been far fewer studies of the respiratory modulation... (Review)
Review
Although respiratory sinus arrhythmia and blood pressure variability have been investigated extensively, there have been far fewer studies of the respiratory modulation of peripheral blood flow in humans. Existing studies have been based primarily on noninvasive measurements using digit photoplethysmography and laser-Doppler flowmetry. The cumulative knowledge derived from these studies suggests that respiration can contribute to fluctuations in peripheral blood flow and volume through a combination of mechanical, hemodynamic, and neural mechanisms. However, the most convincing evidence suggests that the sympathetic nervous system plays the predominant role under normal, resting conditions. This mini-review provides a consolidation and interpretation of the key findings reported in this topical area. Given the need to extract dynamic information from noninvasive measurements under largely "closed-loop" conditions, we propose that the application of analytical tools based on systems theory and mathematical modeling can be of great utility in future studies. In particular, we present an example of how the transfer relation linking respiration to peripheral vascular conductance can be derived using measurements recorded during spontaneous breathing, spontaneous sighs, and ventilator-induced sighs.
Topics: Animals; Blood Flow Velocity; Blood Pressure; Humans; Models, Biological; Peripheral Nervous System; Photoplethysmography; Regional Blood Flow; Respiratory Mechanics; Vasoconstriction
PubMed: 31095465
DOI: 10.1152/japplphysiol.00111.2019 -
Experimental Animals Feb 2021The science of animal welfare has evolved over the years, and recent scientific advances have enhanced our comprehension of the neurological, physiological, and... (Review)
Review
The science of animal welfare has evolved over the years, and recent scientific advances have enhanced our comprehension of the neurological, physiological, and ethological mechanisms of diverse animal species. Currently, the study of the affective states (emotions) of nonhuman animals is attracting great scientific interest focused primarily on negative experiences such as pain, fear, and suffering, which animals experience in different stages of their lives or during scientific research. Studies underway today seek to establish methods of evaluation that can accurately measure pain and then develop effective treatments for it, because the techniques available up to now are not sufficiently precise. One innovative technology that has recently been incorporated into veterinary medicine for the specific purpose of studying pain in animals is called infrared thermography (IRT), a technique that works by detecting and measuring levels of thermal radiation at different points on the body's surface with high sensitivity. Changes in IRT images are associated mainly with blood perfusion, which is modulated by the mechanisms of vasodilatation and vasoconstriction. IRT is an efficient, noninvasive method for evaluating and controlling pain, two critical aspects of animal welfare in biomedical research. The aim of the present review is to compile and analyze studies of infrared thermographic changes associated with pain in laboratory research involving animals.
Topics: Animal Welfare; Animals; Animals, Laboratory; Biomedical Research; Body Temperature; Infrared Rays; Pain; Pain Measurement; Thermography; Vasoconstriction; Vasodilation
PubMed: 32848100
DOI: 10.1538/expanim.20-0052 -
Evolving mechanisms of vascular smooth muscle contraction highlight key targets in vascular disease.Biochemical Pharmacology Jul 2018Vascular smooth muscle (VSM) plays an important role in the regulation of vascular function. Identifying the mechanisms of VSM contraction has been a major research goal... (Review)
Review
Vascular smooth muscle (VSM) plays an important role in the regulation of vascular function. Identifying the mechanisms of VSM contraction has been a major research goal in order to determine the causes of vascular dysfunction and exaggerated vasoconstriction in vascular disease. Major discoveries over several decades have helped to better understand the mechanisms of VSM contraction. Ca has been established as a major regulator of VSM contraction, and its sources, cytosolic levels, homeostatic mechanisms and subcellular distribution have been defined. Biochemical studies have also suggested that stimulation of Gq protein-coupled membrane receptors activates phospholipase C and promotes the hydrolysis of membrane phospholipids into inositol 1,4,5-trisphosphate (IP) and diacylglycerol (DAG). IP stimulates initial Ca release from the sarcoplasmic reticulum, and is buttressed by Ca influx through voltage-dependent, receptor-operated, transient receptor potential and store-operated channels. In order to prevent large increases in cytosolic Ca concentration ([Ca]), Ca removal mechanisms promote Ca extrusion via the plasmalemmal Ca pump and Na/Ca exchanger, and Ca uptake by the sarcoplasmic reticulum and mitochondria, and the coordinated activities of these Ca handling mechanisms help to create subplasmalemmal Ca domains. Threshold increases in [Ca] form a Ca-calmodulin complex, which activates myosin light chain (MLC) kinase, and causes MLC phosphorylation, actin-myosin interaction, and VSM contraction. Dissociations in the relationships between [Ca], MLC phosphorylation, and force have suggested additional Ca sensitization mechanisms. DAG activates protein kinase C (PKC) isoforms, which directly or indirectly via mitogen-activated protein kinase phosphorylate the actin-binding proteins calponin and caldesmon and thereby enhance the myofilaments force sensitivity to Ca. PKC-mediated phosphorylation of PKC-potentiated phosphatase inhibitor protein-17 (CPI-17), and RhoA-mediated activation of Rho-kinase (ROCK) inhibit MLC phosphatase and in turn increase MLC phosphorylation and VSM contraction. Abnormalities in the Ca handling mechanisms and PKC and ROCK activity have been associated with vascular dysfunction in multiple vascular disorders. Modulators of [Ca], PKC and ROCK activity could be useful in mitigating the increased vasoconstriction associated with vascular disease.
Topics: Animals; Calcium Signaling; Humans; Muscle Contraction; Muscle, Smooth, Vascular; Vascular Diseases; Vasoconstriction
PubMed: 29452094
DOI: 10.1016/j.bcp.2018.02.012 -
The Journal of Physiology Sep 2022
Topics: Muscle, Smooth, Vascular; Vasoconstriction
PubMed: 35848099
DOI: 10.1113/JP282890 -
American Journal of Respiratory and... May 2020
Topics: Familial Primary Pulmonary Hypertension; Humans; Mechanistic Target of Rapamycin Complex 1; Pulmonary Arterial Hypertension; Vascular Remodeling; Vasoconstriction
PubMed: 31968178
DOI: 10.1164/rccm.202001-0087ED -
The European Respiratory Journal Jan 2016
Topics: Humans; Hypoxia; Lung; Pulmonary Artery; Pulmonary Circulation; Vasoconstriction
PubMed: 26721961
DOI: 10.1183/13993003.01753-2015 -
British Journal of Clinical Pharmacology Aug 2016Peripheral vasoconstriction has long been described as a vascular adverse effect of β-adrenoceptor blockers. Whether β-adrenoceptor blockers should be avoided in... (Comparative Study)
Comparative Study Meta-Analysis Review
AIM
Peripheral vasoconstriction has long been described as a vascular adverse effect of β-adrenoceptor blockers. Whether β-adrenoceptor blockers should be avoided in patients with peripheral vascular disease depends on pharmacological properties (e.g. preferential binding to β1 -adrenoreceptors or intrinsic sympathomimetic activity). However, this has not been confirmed in experimental studies. We performed a network meta-analysis in order to assess the comparative risk of peripheral vasoconstriction of different β-adrenoceptor blockers.
METHOD
We searched for randomized controlled trials (RCTs) including β-adrenoceptor blockers that were published in core clinical journals in the Pubmed database. All RCTs reporting peripheral vasoconstriction as an adverse effect of β-adrenoceptor blockers and controls were included. Sensitivity analyses were conducted including possibly confounding covariates (latitude, properties of the β-adrenoceptor blockers, e.g. intrinsic sympathomimetic activity, vasodilation, drug indication, drug doses). The protocol and the detailed search strategy are available online (PROSPERO registry CRD42014014374).
RESULTS
Among 2238 records screened, 38 studies including 57 026 patients were selected. Overall, peripheral vasoconstriction was reported in 7% of patients with β-adrenoceptor blockers and 4.6% in the control groups (P < 0.001), with heterogeneity among drugs. Atenolol and propranolol had a significantly higher risk than placebo, whereas pindolol, acebutolol and oxprenolol had not.
CONCLUSION
Our results suggest that β-adrenoceptor blockers have variable propensity to enhance peripheral vasoconstriction and that it is not related to preferential binding to β1 -adrenoceptors. These findings challenge FDA and European recommendations regarding precautions and contra-indications of use of β-adrenoceptor blockers and suggest that β-adrenoceptor blockers with intrinsic sympathomimetic activity could be safely used in patients with peripheral vascular disease.
Topics: Adrenergic beta-Antagonists; Dose-Response Relationship, Drug; Humans; Randomized Controlled Trials as Topic; Sympathomimetics; Vasoconstriction; Vasodilation
PubMed: 27085011
DOI: 10.1111/bcp.12980 -
Prague Medical Report 2020Reversible cerebral vasoconstriction syndrome (RCVS) is characterised by severe thunderclap headaches (with or without the presence of acute neurological symptoms) and... (Review)
Review
Reversible cerebral vasoconstriction syndrome (RCVS) is characterised by severe thunderclap headaches (with or without the presence of acute neurological symptoms) and segmental vasoconstriction of cerebral arteries that resolves spontaneously in a period of three months. Cases have been described in the literature with producing and non-producing masses of metanephrines. Within these reports, associations with cavernous haemangioma, medulloblastoma, colon cancer, paraganglioma, pheochromocytoma, uterine fibroids, among others were found. However, no association with adrenal masses which do not produce metanephrines was found. In this context, we reported the case of a woman with this type of tumour associated with RCVS which provided a treatment challenge, as well as we reviewed the literature on cases of RCVS associated with masses.
Topics: Female; Headache Disorders, Primary; Humans; Paraganglioma; Vasoconstriction; Vasospasm, Intracranial
PubMed: 32553094
DOI: 10.14712/23362936.2020.9 -
Journal of Integrative Neuroscience Sep 2021Peripheral vasoconstriction is a centrally mediated physiological effect known to play an important role in regulating body temperature by adjusting heat exchange with... (Review)
Review
Peripheral vasoconstriction is a centrally mediated physiological effect known to play an important role in regulating body temperature by adjusting heat exchange with the external environment. However, peripheral vasoconstriction as a component of sympathetic activation also occurs following exposure to various salient stimuli and during motivated behavior at stable environmental temperatures. This review aims to consider available evidence suggesting a significant contribution of this peripheral effect to physiological increases in both brain temperature and entry of oxygen and glucose into the brain's extracellular space. While these effects are triggered by neuronal activation, constriction of blood vessels in the skin and most internal organs results in redistribution of blood from the peripheral to central domains, thus dilating cerebral vessels, increasing global cerebral blood flow, and enhancing the intra-brain entry of oxygen and glucose from arterial blood. This powerful influence appears to determine the long duration of physiological increases in both brain temperature and brain levels of glucose and oxygen and their basic similarity across different brain structures. This work underscores the tight interrelationship between the brain and periphery and a significant contribution of cardiovascular effects in providing the enhanced inflow of oxygen and glucose into brain tissue to prevent metabolic deficit during functional neural activation.
Topics: Animals; Body Temperature; Body Temperature Regulation; Brain; Cerebrovascular Circulation; Glucose; Humans; Oxygen; Vasoconstriction
PubMed: 34645109
DOI: 10.31083/j.jin2003080