1. The blood-bathed organ technique was used to study the release of catecholamines, angiotensin II and prostaglandin-like (PL) substances into the circulation during hypercapnia and after haemorrhage in anaesthetized dogs. 2. Elevated blood concentrations of noradrenaline, angiotensin II and prostaglandin-like substances have been detected during both experimental conditions. 3. The rise of arterial blood pressure during hypercapnia and after haemorrhage was associated with elevated concentrations of angiotensin II in the blood and could be abolished by inhibition of the angiotensin I-converting enzyme with SQ 20881. 4. The compensation of arterial pressure during both stresses was significantly impaired by release of prostaglandin-like substances; it could be restored by inhibition of prostaglandin biosynthesis with indomethacin. 5. The results indicate that activation of the renin-angiotensin system represents the major humoral mechanism for the maintenance of arterial pressure during hypercapnic acidosis and after haemorrhage.
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http://dx.doi.org/10.1042/cs051165s | DOI Listing |
J Cereb Blood Flow Metab
January 2025
Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, UK.
To what extent sildenafil, a selective inhibitor of the type-5 phosphodiesterase modulates systemic redox status and cerebrovascular function during acute exposure to hypoxia remains unknown. To address this, 12 healthy males (aged 24 ± 3 y) participated in a randomized, placebo-controlled crossover study involving exposure to both normoxia and acute (60 min) hypoxia (Fi = 0.14), followed by oral administration of 50 mg sildenafil and placebo (double-blinded).
View Article and Find Full Text PDFObjective: This study sought to evaluate the value of a CO field-flooding device in cardiopulmonary bypass (CPB) surgical procedures for congenital heart disease (CHD) performed via a right-side small incision approach.
Methods: Between April 2022 and December 2023, 234 children with simple CHD who underwent CPB via a right-side small incision approach were separated into a control group (n = 93) without the use of a CO field-flooding device and a treatment group (n = 141) in which this device was added to the traditional surgical manual exhaust. Demographic, perioperative, arterial blood gas (ABG), and laboratory test data were then compared between these groups of patients.
Chest
January 2025
Department of Emergency Medicine, Okinawa Prefectural Chubu Hospital, Uruma, Okinawa, Japan.
Background: The optimal target for partial pressure of arterial carbon dioxide (PaCO₂) remains uncertain in patients undergoing veno-arterial extracorporeal membrane oxygenation (VA-ECMO) following out-of-hospital cardiac arrest (OHCA).
Research Question: Are PaCO₂ levels associated with functional outcomes in patients receiving VA-ECMO after OHCA?
Study Design: and Methods: This multicenter, registry-based observational study, conducted from 2014 to 2020, included non-traumatic adult OHCA patients on VA-ECMO with PaCO₂ levels measured within six hours of initiation (initial PaCO₂ set) and at 18-30 hours post-initiation (24-hour PaCO₂ set). PaCO₂ levels were categorized into five groups: hypocapnia (<30 mmHg), low normocapnia (30-<40 mmHg), high normocapnia (40-<50 mmHg), mild hypercapnia (50-<60 mmHg), and moderate to severe hypercapnia (≥60 mmHg).
Physiol Genomics
January 2025
Centre of Marine Sciences (CCMAR/CIMARLA), Campus de Gambelas, Universidade do Algarve, 8005-139 Faro, Portugal.
J Appl Physiol (1985)
January 2025
Centre for Heart, Lung and Vascular Health, University of British Columbia - Okanagan Campus, Kelowna, BC, Canada.
Serotonin (5-HT) is integral to signalling in areas of the brainstem controlling ventilation and is involved in central chemoreception. Selective serotonin reuptake inhibitors (SSRIs), used to effectively increase 5-HT concentrations, are commonly prescribed for depression. The effects of SSRIs on the control of breathing and the potential influence of cerebral blood flow (CBF) have not been directly assessed.
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