Increase of reactive oxygen (ROS) and nitrogen (RNS) species generated by phagocyting granulocytes related to age.

In this present paper the age-induced effect on reactive oxidizing species generated by oxygen (ROS) and nitrogen (RNS) was studied using human phagocyting granulocytes. The ROS and RNS were quantified, respectively, in a chemiluminescence assay and by the measurement of nitrite production. The age-induced reactive oxidizing species generation was studied in healthy subjects ranging from 20 to 80 years old, divided into six age groups: group I, 20-29 years old; group II, 30-39 years old; group III, 40-49 years old; group IV, 50-59 years old; group V, 60-69 years old; and group VI, 70-80 years old. Our results demonstrate a parallelism between generation of the ROS and RNS induced by the age. A significant increase of ROS production was observed from 40 years old (age groups III, IV, V and VI while for RNS this increase was observed only from 50 years old (groups IV, V and VI). These data suggest an increase of oxidizing species generation (ROS/RNS) related to age. The increased generation of ROS (40-49 years old) was induced before the increasing of RNS (50-59 years old) and it may have consequences on inflammation and host defences.

Host defenses in the aged: evaluation of the balance between oxidizing species generation and reducing power in phagocyting human granulocytes.

The respiratory burst reaction has been studied in human granulocytes from normal subjects divided in four age groups: (I) 20-29, (II) 30-39, (III) 40-49, and (IV) 50-59 years old. Zimosan opsonized particles (OZ) were used to evaluate, simultaneously, the reducing power and the oxidizing species generation. Our results showed a strong parallelism and a direct correlation between oxidizing species generation and reducing power in the groups (I) and (II), in presence or in the absence of opsonized zimosan. However, the age groups (III) and (IV) showed an increase in the free radicals generation and a significant decrease in the cellular reducing power. This inverse correlation observed between oxidizing/reducing power in the (III) and (IV) age groups may suggest a metabolic cellular disequilibrium.