Nitric oxide and inflammatory joint diseases

Area of Science:

• Biochemistry
• Immunology
• Rheumatology

Background:

• Nitric oxide (NO) is synthesized from L-arginine by NO synthases.
• Three main NO synthase isoenzyme groups exist: two constitutive and one inducible.
• The inducible NO synthase produces large amounts of NO with cytotoxic effects upon induction by cytokines or endotoxin.

Purpose of the Study:

• To investigate the role of nitric oxide in inflammatory joint diseases.
• To evaluate the therapeutic potential of NO synthase inhibition in arthritis.

Main Methods:

• Review of animal models of arthritis and human studies (rheumatoid arthritis, spondyloarthropathies).
• Analysis of the effects of NO synthase inhibitors in experimental arthritis.
• Inference of therapeutic benefits from glucocorticoid treatment, which inhibits inducible NO synthase.

Main Results:

• High levels of NO are implicated in inflammatory joint diseases.
• NO synthase inhibitors significantly reduced disease activity in experimental arthritis.
• Glucocorticoids reduce NO synthesis and disease activity in humans, suggesting indirect NO inhibition benefits.

Conclusions:

• Pathologically enhanced NO synthesis is a significant factor in inflammatory joint diseases.
• Selective inhibition of inducible NO synthase represents a novel therapeutic strategy for inflammatory joint diseases.
• Further research into NO synthase inhibitors could lead to new treatments for arthritis.