Effects of experimental Mycoplasma pulmonis infection on sensory neuropeptides and airway mucosa in the rat

Abstract

The effect of airway infection on neurogenic inflammation is not known. The present study examines the effect of Mycoplasma pulmonis infection on the sensory neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP) in the trigeminal ganglion and in the mucosa of the nose and trachea in rats. We compared germ-free (GF), conventionally raised (CV) and specific pathogenfree (SPF) rats.The concentrations of SP and CGRP in the nasal mucosa were assessed with immunohistochemistry, and their prohormonal transcripts in the trigeminal ganglion were assessed with Northern blot. Mucosa was also processed for light microscopy and electron microscopy.SP-like immunoreactivity was greater in the nasal mucosa of infected animals than in uninfected controls. CGRP-like immunoreactivity was greater in the nasal septum, but not in the nasal turbinate, of infected than uninfected animals. In contrast, no change was evident in the expression levels of the prohormonal transcripts in the trigeminal ganglion. Infected nasal and tracheal mucosa was oedematous and locally infiltrated with inflammatory cells. In the nose of uninfected GF rats, subepithelial lymphoid aggregations were scarce and appeared inactive.We conclude that Mycoplasma pulmonis infection results in increased immunoreactivity of substance P, probably within nerves. There was no clear evidence of increased synthesis of the precursors of substance P and calcitonin gene-related peptide.

Management of chronic pain in whiplash injury

“…The plasma levels of SP are also raised in other painful conditions, [17][18][19][20] and those of CGRP are altered in soft-tissue injuries, 21 in chronic pain 22 and infection. 23 Carpal tunnel decompression is indicated in patients who have chronic neck, shoulder and arm pain after a whiplash injury. Changes in the plasma levels of neurotransmitter peptides and independent clinical and functional outcomes confirm the benefits of this treatment.…”

Mycoplasma infection and inflammatory effects on laboratory rats bred for experimental research

“…Furthermore, the most important consequence of M. pulmonis infection, beyond its direct pathogenic effects to the animal, can be the consequence of its presence in the analysis of experimental data. For instance, it may affect ciliary cell function, cellular kinetics 3 , neurogenic inflammation 4,5 , natural killer cell activity 6,7 , local and systemic immune response 2,8 , and induction of the production of several cytokines 9 . Immune system activation by mollicutes induces the liberation of preinflammatory substances and polyclonal proliferation of B and T lymphocytes 10 .…”

INFECÇÃO POR Mycoplasma pulmonis EM RATOS WISTAR PROVENIENTES DE BIOTÉRIO

“…Entretanto, o impacto mais significante da infecção por M. pulmonis pode dever-se à sua interferência na interpretação dos resultados experimentais obtidos com animais infectados. Estes microrganismos podem, por exemplo, alterar a função ciliar e a cinética celular (11), a inflamação neurogênica (14,15), a ativação das células NK (9,22) e a resposta imune local e sistêmica (20,21), com indução da produção de várias interleucinas (5). Já M. arthritidis induz uma doença aguda limitada, que pode ser sistêmica e passível de autoinfecção em ratos, e inclui a poliartrite séptica como uma manifestação primária (24).…”