Chronic Stress Induces Structural Alterations in Splenic Lymphoid Tissue That Are Associated with Changes in Corticosterone Levels in Wistar-Kyoto Rats

Abstract

Major depressive disorder patients present chronic stress and decreased immunity. The Wistar-Kyoto rat (WKY) is a strain in which the hypothalamic-pituitary-adrenal axis is overactivated. To determine whether chronic stress induces changes in corticosterone levels and splenic lymphoid tissue, 9-week-old male rats were subject to restraint stress (3 h daily), chemical stress (hydrocortisone treatment, 50 mg/Kg weight), mixed stress (restraint plus hydrocortisone), or control treatment (without stress) for 1, 4, and 7 weeks. The serum corticosterone levels by RIA and spleens morphology were analyzed. Corticosterone levels as did the structure, size of the follicles and morphology of the parenchyma (increase in red pulp) in the spleen, varied depending on time and type of stressor. These changes indicate that chronic stress alters the immune response in the spleen in WKY rats by inducing morphological changes, explaining in part the impaired immunity that develops in organisms that are exposed to chronic stress.

Effect of breeder age and lighting regimen on growth performance, organ weights, villus development, and bursa of fabricius histological structure in broiler chickens

“…Spleen comprises two principal compartments: red pulp, which filters the blood of foreign material and damages old erythrocytes, and white pulp, which initiates immune reactions to blood-borne antigens (Mebius and Kraal 2005). In rodents, Hernandez et al (2013) found that red pulp expanded at the expense of white pulp due to strained stress exposure, while the histological structure of spleen of the groups in this study did not show a clear difference. Duve et al (2011) stated that to split dark period into two periods per 4 h may not confer considerable welfare benefits to the young chicks and may affect the quality of rest, which could be related to the interruption in the melatonin rhythm (Yamada et al 1988).…”

The protective effect of the Vacha rhizome extract on chronic stress-induced immunodeficiency in rat

“… 1998 ), reduction in the germinal center of lymphoid follicle and loss of islands of white pulp of the spleen and decrease in size of the follicles and the marginal zone of the spleen (Hernandez et al. 2013 ). Similar to the earlier reports, in the present study chronic stress resulted in shrinkage of white pulp and germinal center and loss of islands of white pulp of the spleen, thymic involution and shrinkage of germinal center of axillary lymph node.…”

Protective Effect of Sphaerococcus coronopifolius Crude Extract in Combination with Bacillus Calmette-Guerin on Ligature-Induced Depression in Female Wistar Rats

“…Supplementary, the repeat restraint and exogenous corticosterone have low adrenal gland weight. 66 In summary, the present study examined the mechanisms of the potential antidepressant-like actions for S. coronopifolius extract in combination with low dose of BCG. This study elicited algae extract as the principal drug for the treatment, whereas BCG served as an adjuvant.…”

“…65 Chronic stress has been described to induce structural alterations in splenic lymphoid tissue in rats. 66 Granulomatous inflammation, which is a distinctive pattern of chronic inflammatory reaction characterized by focal accumulation of activated macrophages, can generally develop an epitheloid appearance. 67 Epitheloid cells can fuse to form giant cells with diameter of 40-50 µm.…”