Testosterone and dihydrotestosterone modulate the redox homeostasis of endothelium

The concept that inflammation participates pivotally in the pathogenesis of atherosclerosis and its complications has gained considerable attention, but has not yet entered clinical practice. Experimental work has elucidated molecular and cellular pathways of inflammation that promote atherosclerosis. The recognition of atherogenesis as an active process rather than a cholesterol storage disease or a repository of calcium has highlighted some key inflammatory mechanisms. For example, mononuclear phagocytes contribute to all stages of this disease, illustrating the link between inflammation and atherosclerosis. From a clinical perspective, harnessing inflammation may now help target therapeutics, change guidelines, and enter daily practice. Multiple lines of incontrovertible evidence have proven a causal role for low-density lipoprotein (LDL) cholesterol in atherosclerosis, and we have highly effective tools for lowering LDL, consequently reducing events. Yet, even with intense LDL reduction, events still occur. Inflammation can explain some of this residual risk. An anti-inflammatory intervention has now proven capable of improving outcomes in individuals well treated with LDL-lowering agents. A suite of trials are now pursuing anti-inflammatory therapies in this context. Assessment and treatment of residual inflammatory risk are poised to provide new inroads into preventive cardiology. This brief review aims to explore the potential mechanisms underlying the association of inflammation and atherogenesis, and their clinical consequences.

Oxidative stress, defined as a disturbance in the balance between the production of reactive oxygen species (free radicals) and antioxidant defenses, is discussed in relation to its possible role in the production of tissue damage in diabetes mellitus. Important free radicals are described and biological sources of origin discussed, together with the major antioxidant defense mechanisms. Examples of the possible consequences of free radical damage are provided with special emphasis on lipid peroxidation. Finally, the question of whether oxidative stress is increased in diabetes mellitus is discussed.