Age-related changes of the pituitary folliculo-stellate cells in rats in chronic stress

Abstract

Folliculo-stellate cells are known as S-100 protein immunopositive cells of the anterior lobe of pituitary gland which are not secreting hormones and are presumed to be organ specific stem cells of the adenohypophys. Their role in adaptation of the body to stress remains unclear. Aim: to evaluate dynamics of folliculo-stellate and hormone-producing cells in rats of different age in chronic stress exposure. Materials and methods; sprague-Dawley rats aged 1, 3, 6 and 12 months were exposed to chronic immersion immobilization stress. Histological section of the pituitary glands were stained immunohistochemically with subsequent image analysis. Results: in control rats S-100 protein-immunopositive cells increased in number with age and negatively correlated with the number of ACTH-positive cells. In experimental animals aged 1 and 3 months volume density of S-100 protein-immunoreactive cells significantly decreased and negatively correlated with ACTH-positive cells, while in 6 month old rats it was only slightly decreased and in 12 months old animals showed tendency to increase. Conclusions: results of the study demonstrating capacity of the folliculo-stellate cells to contribute to the plasticity of the hypothalamo-hypophyseo-adrenal axis in chronic stress exposure at different age.