Vampires, Pasteur and reactive oxygen species

FEBS Letters

Oliveira, Pedro L.¹  Oliveira, Marcus F.¹ 

[1] Departamento de Bioquı́mica Médica, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Av. Brigadeiro Trompowsky, s/n, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ 21941-590, Brazil

关键词: Hemoglobin;    Energy metabolism;    Free radical;    Parasite;    Antioxidant;   

DOI  :  10.1016/S0014-5793(02)03026-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Several species of parasites show a reduction of their respiratory activity along their developmental cycles after they start to feed on vertebrate blood, relying on anaerobic degradation of carbohydrates to achieve their energy requirements. Usually, these parasites choose not to breathe despite of living in an environment of high oxygen availability such as vertebrate blood. Absence of the ‘Pasteur effect’ in most of these parasites has been well documented. Interestingly, together with the switch from aerobic to anaerobic metabolism in these parasites, there is clear evidence pointing to an increase in their antioxidant defences. As the respiratory chain in mitochondria is a major site of production of reactive oxygen species (ROS), we propose here that the arrest of respiration constitutes an adaptation to avoid the toxic effects of ROS. This situation would be especially critical for blood-feeding parasites because ROS produced in mitochondria would interact with pro-oxidant products of blood digestion, such as haem and/or iron, and increase the oxidative damage to the parasite's cells.

【 授权许可】

Unknown