Cell death in the rat thymus: a minireview.

During the last decades, the literature has clearly established the fundamental role of the thymus in the development of an effective immune system. During thymocyte development and maturation, potentially autoreactive thymocytes are eliminated by a process known as apoptosis or programmed cell death responsible for the negative selection occurring within the thymus. This process is in sharp contrast to other types of cell death referred to as necrosis. Actually, three different types of cell death have been recently observed morphologically in the rat thymus, i.e. necrosis, apoptosis and clustered cell death. Moreover, among the numerous factors influencing thymocyte cell death, particular attention has been paid to hormones, chemicals, biological compounds and physical agents that may influence the type and/or the extent of cell death. Finally, a brief overview has been devoted to the contribution of mitochondria, nitric oxide, glutathione and intracellular levels of cations in addition to the activity of genes as cdk2, p53, Fas and members' of the Bcl2 family in modulating rat thymus cell death.