Hemodynamic and blood volume changes, systolic time intervals, and baroreflex mechanisms were studied in 20 patients with hypertension after methyldopa (12 +/- 0.9 mg/kg/day). The drug was administered orally during 7 days' hospitalization on a normal sodium diet (110 mEq/day). There was a fall in blood pressure and in total peripheral resistance, without significant change in cardiac index, heart rate, and stroke index. There were increases in plasma and blood volume (p less than 0.05) but no change in cardiopulmonary blood volume or systolic time intervals. The unchanged heart rate was associated with an increased sensitivity ( less than 0.05) of the baroreflex mechanisms. The study supports the view that the unchanged cardiac output after methyldopa is related to important changes in control of cardiac output, including redistribution of blood volume and modifications in baroreflex mechanisms.

Download full-text PDF

Source
http://dx.doi.org/10.1002/cpt1979253266DOI Listing

Publication Analysis

Top Keywords

blood volume
16
cardiac output
12
baroreflex mechanisms
12
systolic time
8
time intervals
8
heart rate
8
blood
5
alpha-methyldopa cardiac
4
output hypertension
4
hypertension hemodynamic
4

Similar Publications

Imaging of the Placenta.

Clin Obstet Gynecol

March 2025

Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, University of Maryland, College Park, Maryland.

Placental imaging is crucial in prenatal care, offering insights into both normal and abnormal pregnancies. Traditional methods like grayscale ultrasound and magnetic resonance imaging evaluate placental anatomy, whereas Doppler ultrasound is used for functional assessment. Recent advancements include functional magnetic resonance imaging and advanced Doppler software for demonstrating placental density and visualizing spiral arteries.

View Article and Find Full Text PDF

Background: Systemic inflammation, aging, and type 2 diabetes (T2D) lead to varying degrees of cardiovascular dysfunction and impaired aerobic exercise capacity. This study evaluates the impact of inflammation and sex differences on coronary and peripheral vascular function and exercise capacity in older individuals with and without T2D.

Methods: Older individuals (aged≥65 years) underwent biochemical and tissue inflammatory phenotyping, cardiopulmonary exercise testing, cardiovascular magnetic resonance imaging, and vascular reactivity testing.

View Article and Find Full Text PDF

The prognostic impact of arterial spin labeling hyperperfusion in acute ischemic stroke: a systematic review and meta-analysis.

Acta Radiol

January 2025

Department of Radiology & Institute of Rehabilitation and Development of Brain Function, Nanchong Central Hospital, The Second Clinical Medical College of North Sichuan Medical College, Nanchong, Sichuan, PR China.

Hyperperfusion is related to vessel recanalization, tissue reperfusion, and collateral circulation. To determine the prognostic impact of hyperperfusion after an acute ischemic stroke (AIS) identified by arterial spin labeling (ASL) cerebral blood flow. Studies published in PubMed, Embase, and Cochrane Library databases were searched.

View Article and Find Full Text PDF

Rat models of postintracerebral hemorrhage pneumonia induced by nasal inoculation with or intratracheal inoculation with LPS.

Front Immunol

January 2025

State Key Laboratory of Traditional Chinese Medicine Syndrome, Department of Neurology, Guangdong Provincial Academy of Chinese Medical Sciences, Guangdong Provincial Hospital of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.

Background: A stable and reproducible experimental bacterial pneumonia model postintracerebral hemorrhage (ICH) is necessary to help investigating the pathogenesis and novel treatments of Stroke-associated pneumonia (SAP).

Aim: To establish a Gram-negative bacterial pneumonia-complicating ICH rat model and an acute lung injury (ALI)-complicating ICH rat model.

Methods: We established two standardized models of post-ICH pneumonia by nasal inoculation with () or intratracheal inoculation with lipopolysaccharide (LPS).

View Article and Find Full Text PDF

Background: Reduced effect of antiplatelet therapy has been reported in patients with ST-segment elevation myocardial infarction (STEMI). This could partly be explained by an increase of highly reactive immature platelets.

Objectives: To investigate changes in platelet maturity and reactivity after acute STEMI.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!