Chronic varied stress modulates experimental autoimmune encephalomyelitis in Wistar rats

CORREA SG; RODRIGUEZ GALAN MC,; RIVERO VE; RIERA CM

BRAIN BEHAVIOR AND IMMUNITY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 1998 vol. 12 p. 134 - 148

0889-1591

Stress disturbs homeostasis by altering the equilibrium of various hormones which havea significant impact on immune responses. Few studies have examined the influence ofstressors on autoimmune disease in animal models. In our work, we studied the effects oflong-term exposure (14 days) to chronic varied stress (CVS) in a model of experimentalautoimmune encephalomyelitis (EAE) in Wistar rats. We studied whether the exposure toCVS before or after the immune challenge would correlate with differences in the clinicalcourse of the disease. We also examined whether the CVS would modulate the magnitudeof the cellular or the humoral immune response. We observed opposite effects on theclinical signs in animals stressed before or after the immune challenge. The clinical signs ofthe disease were attenuated in animals stressed before but not after the immune challenge.Relationships were found in the modulation of the clinical severity related to the time ofexposure to the CVS, the histological alterations and the proliferative results. Stressedanimals with milder clinical signs presented an exacerbated humoral response against myelinantigens while stressed animals with more severe clinical symptoms exhibited a significantlydiminished one. Besides, we detected the presence of specific IgG1 associatedwith the exposure to CVS before the induction of EAE. Our results show that, dependingon the timing of the exposure of Wistar rats to the CVS, the neuroendocrine disbalancefavors a more pronounced humoral or cellular profile of the response.