DOES THE RHEUMATOID ARTHRITIS AFFECT THE ENTERIC NERVOUS SYSTEM?

Area of Science:

• Gastroenterology
• Neuroscience
• Immunology

Background:

• Rheumatoid arthritis (RA) is linked to oxidative stress and systemic effects, yet its impact on the enteric nervous system (ENS) remains understudied.
• Investigating neurodegeneration in arthritic diseases is crucial for understanding systemic disease manifestations.
• The gastrointestinal tract's role in RA's systemic effects warrants further exploration.

Purpose of the Study:

• To assess the effects of rheumatoid arthritis on nitrergic neuron density and somatic area in the myenteric neurons of the ileum.
• To evaluate changes in the morphometric areas of CGRP-IR and VIP-IR varicosities in the ileum of arthritic rats.
• To determine the impact of arthritis on the enteric nervous system (ENS) using a rat model.

Main Methods:

• Arthritis was induced in male Holtzmann rats using Freund's Complete Adjuvant.
• Ileum whole-mount preparations were analyzed using immunohistochemistry for nNOS, CGRP, and VIP.
• Quantification of nitrergic neurons and morphometric analysis of varicosities were performed.

Main Results:

• Arthritic rats showed a 6% reduction in ileal area compared to controls.
• No significant difference in nitrergic neuron density was observed between groups.
• Arthritic rats exhibited reduced nitrergic neuronal somatic area and VIP-IR varicosity areas, alongside an increase in CGRP-IR varicosity areas.

Conclusions:

• Arthritis did not alter the number of nitrergic neurons in the rat ileum.
• Reduced ileal area and nitrergic somatic/VIP-IR varicosity areas suggest a detrimental effect of arthritis on the ENS.
• Further research is needed to fully elucidate the complex interactions between rheumatoid arthritis and the gastrointestinal nervous system.