Recreational scuba diving: negative or positive effects of oxidative and cardiovascular stress?

Abstract

Environmental conditions and increased physical activity during scuba diving are followed by increased production of free radicals and disturbed redox balance. Redox balance disorder is associated with damage of cellular components, changes of cellular signaling pathways and alterations of gene expression. Oxidative stress leads to increased expression of sirtuins (SIRTs), molecules which play an important role in the antioxidant defense, due to their sensitivity to the changes in the redox status and their ability to regulate redox homeostasis. These facts make SIRTs interesting to be considered as molecules affected by scuba diving and in that sense, as potential biomarkers of oxidative status or possible drug targets in reduction of reactive oxygen species (ROS) accumulation. In addition, SIRTs effects through currently known targets make them intriguing molecules which can act positively on health in general and whose expression can be induced by scuba diving.A demanding physical activity, as well as other circumstances present in scuba diving, has the greatest load on the cardiovascular function (CV). The mechanisms of CV response during scuba diving are still unclear, but diving-induced oxidative stress and the increase in SIRTs expression could be an important factor in CV adaptation. This review summarizes current knowledge on scuba diving-induced oxidative and CV stress and describes the important roles of SIRTs in the (patho)physiological processes caused by the redox balance disorder.

Figure 1

Calorie restriction, cold exposure and exercise induce SIRT3 expression and activity in tissues and organs with high oxidative capacity such as heart, liver, skeletal muscle and brown adipose tissue (BAT). Increased expression and activity of SIRT3 is important for the adaptation of different physiological processes in these tissues and organs.

Figure 2

Biological functions of SIRT1. Resveratrol, caloric restriction and exercise (scuba diving?) can induce SIRT1, leading to changes of many biological functions in different organs and tissues. CV – cardiovascular.

Figure 3

Schematic presentation of the potential connection between the increase in ROS production during dives and an increase of expression or activation of sirtuins, along with many age-related diseases linked to the activity of sirtuins.