Plasticity of the responses to chronic hypoxia and dietary restriction in an aged organism: evidence from the Drosophila model.

Major cardiovascular diseases arise as consequences of a reduced blood flow to oxygen consuming organs such as the brain and the heart. Their incidence and consequences increase with ageing and inappropriate nutrition conditions. In this study we compared the responses of young (1 day old) or aged (1 month old) Drosophila to dietary restriction and chronic hypoxia. Changing the two major diet components (sucrose and yeast) had complex and non linear consequences on longevity. Ageing and hypoxia completely remodelled the longevity/nutrient reaction norm. Aged flies required more sucrose and less yeast than young flies and became insensitive to dietary restriction by food dilution. The responses to chronic hypoxia were largely age independent and strongly diet dependent. For instance rich diets sensitized Drosophila to chronic hypoxia and hypoxia increased the life span of starving flies (aged or young). The results highlight the importance of nutrition conditions when assessing ageing and hypoxic tolerance in the Drosophila system.