INVESTIGADORES
WALD Miriam Ruth
artículos
Título:
Effects of chronic mild stress on lymphocyte proliferative response. Participation of serum thyroid hormones and corticosterone
Autor/es:
SILBERMAN DM; WALD MR; GENARO AM
Revista:
INTERNATIONAL IMMUNOPHARMACOLOGY
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2002 vol. 2 p. 487 - 497
ISSN:
1567-5769
Resumen:
There is
increasing evidence that stress produces changes in various immune processes.
Some of these changes may be due to neurochemical and hormonal alterations
including thyroid hormones levels. This work was carried out to study the impact
of chronic mild stress (CMS) exposure on proliferative responses and its
correlation with serum thyroid hormone levels. In addition, the influence of
serum corticosterone levels on these responses was also studied. For this
purpose, mice were submitted from 1 to 6 weeks to a CMS model. After undergoing
the stress schedule for 4 weeks, an alteration in the proliferative response
was observed. Lymphocytes from exposed animals showed a decrease in T-cell
response to con- canavalin-A (Con A) and phytohemagglutinin (PHA) and an
increase in B-cell proliferation to lipopolysaccharides (LPS). In parallel, a
reduction in T3 and T4 serum levels was observed. On the contrary, serum
corticosterone levels increased in animals exposed to CMS for 1 or 2 weeks and
then return to normal values. Lowering serum thyroid hormone levels by propylthiouracil
(PTU) treatment negatively modulates T-cell response without affecting B-cell
response. On the other hand, the substitutive T4 treatment in stressed animals
improved significantly the proliferative T-cell response. Non-significative changes
in CD4/CD8 ratio were observed neither in stressed, PTU- or T4-treated animals.
Taken together, our results suggest an impact of chronic stress on thyroid
function that in turn alters T-cell response. These findings may help to
elucidate the physiological mechanisms through which stress plays a roll in the
etiology of many diseases.