The SHR has an atrophied thymus and suppressed indices of immune function with extensive lymphocyte apoptosis. Adrenalectomy in the SHR reduces apoptotic death rates of lymphocytes in the thymus. Supplementation with a glucocorticoid enhances the apoptosis in the thymus and several other organs. The process may involve DNA binding of the glucocorticoid receptor. Glucocorticoids disrupt mitochondrial transmembrane potentials, deplete nonoxidized glutathione levels, increase the production of reactive oxygen species, elevate cytosolic free Ca2+ levels and produce nuclear and cytoplasmic shape changes. There is evidence for oxygen free radical involvement in early apoptosis of dexamethasone-treated splenocytes and SHR smooth muscle cells.
Was this article helpful?
This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.