The Effects of Propofol and Thiopental on Nitric Oxide Production and Release in Erythrocytes

Summary

Hypotension is frequently encountered during the use of these commonly used intravenous anaesthetic agents (thiopental and propofol). This is thought to be a consequence of their effects on the sympathetic nervous system, myocardial contractility or vascular tone. However, propofol causes a greater fall in systemic arterial blood pressure than any other drug used for induction of anaesthesia. Propofol causes profound vasodilation, whereas its myocardial depressant effect is not clear. The vasodilatation occurs in both arterial and venous systems. The decrease in systemic arterial blood pressure after thiopental induction is mainly due to peripheral vasodilatation caused by depression of the medullary vasomotor centre and inhibition of the sympathetic nervous system. However, how this peripheral vasodilator effect occurs after both drugs and which mediators accompany it have not yet been fully elucidated. In previous studies, it has been emphasised that systemic vasodilation may be related with increased formation of nitric oxide (NO), a small gaseous and lipophilic molecule which plays an important role in the regulation of vascular homeostasis and haemoregulation. It is important to elucidate the mechanisms that may mediate thiopental- and propofol-mediated vasodilatation in future studies in order to help the methods and treatments that can be developed to prevent hypotension caused by these drugs, which are widely used in clinical practice. Therefore, the aim of this study was to investigate the effects of thiopental and profol on erythrocyte NO synthase activity and erythrocyte-mediated NO release.

Conditions

• Effect of Drug

Interventions

DRUG

Propofol

Venous blood samples will be taken from the patients included in the study and incubated with propofol (dose: 100, 250, 500 and 1000µM) after appropriate procedures in the laboratory environment. . After incubation, all resuspensions will be subjected to flow cytometric analysis to evaluate erythrocyte NO synthase activity and erythrocyte-mediated NO release.

DRUG

Thiopental

Venous blood samples will be taken from the patients included in the study and incubated with thiopental (dose: 100, 250, 500 and 1000µM) after appropriate procedures in the laboratory environment. . After incubation, all resuspensions will be subjected to flow cytometric analysis to evaluate erythrocyte NO synthase activity and erythrocyte-mediated NO release.

Sponsors & Collaborators

• Melike Cengiz

  lead OTHER

Principal Investigators

• Ulku Arslan Yildiz, MD · Akdeniz University School of Medicine, Department of Anesthesiology and Intensive Care, Turkey

• Pinar Ulker, PhD · Akdeniz University School of Medicine, Department of Physiology

• Ahmet Yildirim · Akdeniz University School of Medicine, Department of Physiology

• Ayse Gulbin Arici, Professor · Akdeniz University School of Medicine, Department of Anesthesiology and Reanimation, Turkey

• Murat Yilmaz, Professor · Akdeniz University School of Medicine, Department of Anesthesiology and Intensive Care, Turkey

Study Design

Allocation

NON_RANDOMIZED

Purpose

OTHER

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

45 Years

Sex

MALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-03-01

Primary Completion

2024-07-01

Completion

2024-07-07

Countries

• Turkey (Türkiye)

Study Locations