Related Experiment Video
Updated: Jul 6, 2026
07:56
Isolation of Intrapulmonary Artery and Smooth Muscle Cells to Investigate Vascular Responses
Published on: June 8, 2022
Endogenous antimicrobial peptide LL-37 induces human vasodilatation
I Berkestedt1, A Nelson, M Bodelsson
1Section of Anaesthesiology and Intensive Care, Department of Clinical Sciences, Lund University, SE-221 85 Lund, Sweden.
British Journal of Anaesthesia
|April 10, 2008
Summary
The antimicrobial peptide LL-37 causes blood vessels to relax by acting on the ALX receptor in veins. This finding suggests potential new treatments for septic shock involving ALX antagonists.
Area of Science:
- Vascular biology
- Immunology
- Pharmacology
Background:
- Septic shock involves vasodilation and innate immune activation, releasing antimicrobial peptides like LL-37.
- LL-37 attracts leukocytes via the lipoxin A(4) receptor (ALX), which is also found in vascular endothelial cells.
Purpose of the Study:
- To investigate the effect of LL-37 on vascular tone for potential pharmacological intervention in septic shock.
Main Methods:
- Human omental arteries and veins were studied for smooth muscle activity in organ baths.
- Gene expression was analyzed using reverse transcriptase-polymerase chain reaction.
Main Results:
- LL-37 induced endothelium-dependent relaxation in veins, but not arteries, at micromolar concentrations.
- This relaxation was mediated via the ALX receptor and involved nitric oxide and EDHF, but not prostanoids.
- ALX expression was confirmed in the vein endothelium.
Conclusions:
- The antimicrobial peptide LL-37 induces endothelium-dependent relaxation in human omental veins through endothelial ALX.
- LL-37 may contribute to vasodilation in sepsis, and ALX antagonists could be a potential therapeutic strategy.
Related Concept Videos
01:25Acute Inflammation III: Local and Systemic Effects
Acute inflammation produces a coordinated set of local and systemic changes that limit injury, eliminate pathogens, and initiate repair. These responses arise within minutes of infection, trauma, or chemical insult and are driven by vascular alterations and leukocyte-derived mediators. When the stimulus resolves, the reaction typically abates within days.Local EffectsAt the site of injury, arteriolar vasodilation increases blood flow, resulting in redness and warmth. Simultaneously, increased...
01:23Antihypertensive Drugs: Vasodilators
Vasodilators, primarily affecting the smooth muscles within arterial and venous walls, are commonly used for hypertension treatment. Medications such as minoxidil and hydralazine primarily target arteries and arterioles, while sodium nitroprusside acts on arterioles and venules. Minoxidil, functioning as a prodrug, is metabolized by hepatic sulfotransferase into its active form, minoxidil sulfate, after oral administration. This metabolite binds to the sulfonylurea receptor (SUR) component of...
01:23Antimicrobial Proteins
Antimicrobial proteins are important components of the immune system. They aid the body in combating pathogens by either killing them directly or hindering their replication processes. Four main types of antimicrobial substances are interferons, the complement system, iron-binding proteins, and antimicrobial proteins.
Interferons
Interferons (IFNs) are proteins produced by lymphocytes, macrophages, and fibroblasts infected with viruses. While IFNs cannot prevent viruses from entering and...
Interferons
Interferons (IFNs) are proteins produced by lymphocytes, macrophages, and fibroblasts infected with viruses. While IFNs cannot prevent viruses from entering and...
01:26Acute Inflammation I: Inflammatory Response
Acute inflammation is a rapid, short-lived physiological response to tissue injury or infection, designed to eliminate harmful agents and initiate repair. This tightly regulated process typically lasts from minutes to several days and is triggered by factors such as microbial invasion, physical trauma, or chemical injury.Recognition and Mediator ReleaseThe inflammatory response begins when resident immune cells—such as mast cells, macrophages, and dendritic cells—detect damage-associated...