To determine the effects of parasympathetic blockade and beta-blockade on the elastic response of aortic stiffness to vasopressive interventions, we studied 5 unanesthetised adult mongrel dogs by means of a pressure microtransducer and two ultrasonic crystals positioned at opposing sites in the proximal descending thoracic aorta which were used for diameter measurements. Systolic and diastolic changes in pressure and diameter were used to calculate Peterson and incremental elastic moduli. Acute hypertension was induced using infusions of epinephrine during the control period and later propranolol (1.5 mg/kg) plus atropine (0.2 mg/kg). Percent variations of mean aortic diameter were correlated to percent variations in mean aortic pressure in the control period and after autonomic blockade (P less than .001). The slopes of these correlations in the control group were higher than after autonomic blockade (P less than .05). Correlations were also found between Peterson and incremental elastic moduli and mean pressure in the control group and after autonomic blockade (P less than .001). The slopes of the correlations of incremental elastic modulus and Peterson's modulus versus mean aortic pressure were lower in the control group than after blockade (P less than .001). We conclude that in conscious dogs, autonomic blockade with propranolol and atropine decreased the distension and increased the stiffness of the aortic wall in response to acute hypertension mediated by epinephrine.
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http://dx.doi.org/10.1093/ajh/3.6.476 | DOI Listing |
A A Pract
January 2025
From the Department of Anesthesia and Perioperative Medicine, University of California Los Angeles (UCLA) David Geffen School of Medicine, UCLA Health System, Los Angeles, California.
Management of refractory ventricular fibrillation (VF) in patients with implantable implantable cardioverter defibrillator (ICD) presents a therapeutic challenge. We present a case of pediatric refractory ventricular tachycardia (VT)/Torsade de Pointe managed effectively with bilateral stellate ganglion block (SGB) with a long-acting local anesthetic for 18 days as a bridge to more definitive surgical management.
View Article and Find Full Text PDFClin Auton Res
January 2025
Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana, USA.
Purpose: Resting beat-to-beat blood pressure variability is a strong predictor of cardiovascular events and mortality. However, its underlying mechanisms remain incompletely understood. Given that the sympathetic nervous system plays a pivotal role in cardiovascular regulation, we hypothesized that alpha-1 adrenergic receptors (the main sympathetic receptor controlling peripheral vasoconstriction) may contribute to resting beat-to-beat blood pressure variability.
View Article and Find Full Text PDFRespir Res
January 2025
Department of Pulmonary and Critical Care Medicine, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, 200092, China.
Background: Neuroimmune interaction is an underestimated mechanism for lung diseases, and cryoablation is a competitive advantageous technique than other non-pharmacologic interventions for peripheral nerve innervating the lung. However, a lack of cryodenervation model in laboratory rodents leads to the obscure mechanisms for techniques used in clinic.
Method: Herein, we developed a novel practical method for mouse peripheral nerve cryoablation, named visualized and simple cryodenervation (VSCD).
Am J Physiol Heart Circ Physiol
February 2025
Department of Pharmacology, Physiology and Neurobiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States.
Lower body negative pressure (LBNP) has been used for decades in humans to model arterial baroreceptor unloading and represents a powerful tool for evaluating cardiovascular responses to orthostatic challenges. However, LBNP studies in animals have been limited to conditions of anesthesia or sedation, where cardiovascular reflexes are altered. Given the consequent uncertainties, the usefulness of LBNP studies in these preclinical models has been severely hampered.
View Article and Find Full Text PDFJ Acad Consult Liaison Psychiatry
January 2025
Department of Psychiatry and Behavioral Neurosciences, University of South Florida, Tampa, FL, USA, 33613; Department of Psychiatry, University of Florida College of Medicine, Gainesville, FL, 32608.
Background: Neuroleptic malignant syndrome (NMS) is a rare yet potentially fatal iatrogenic syndrome that can manifest with life-threatening symptoms. Theorized to be caused by the dopamine-blocking effects of certain medications, such as antipsychotics, or the withdrawal of dopaminergic agents, NMS is characterized by hyperthermia, autonomic instability, altered mental status, and muscular rigidity. Most treated cases resolve within weeks; however, in some cases, residual catatonic symptoms can persist for months after the resolution of acute hyperthermic and hypermetabolic symptoms.
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