Carotid Body HIF-1α, VEGF and NOS Expression during Aging and Hypoxia

Carotid body (CB) undergoes several morphological, physiological and biochemical changes during aging, hypoxia and hyperoxia (Di Giulioet al., 1998; Lahiriet al., 1990; Lahiri et al.,2000). CB releases several substances like dopamine, acetilcholine, nerpinephrine, erythropoietin, substance P, and it detects pO2 and pCO2 levels in the blood, it regulates ventilation according to oxygen needs and body requirements for homeostasis maintenence (Bunnet al., 1996). The ventilatory response to hypoxia is characterised by increase in volume and ventilatory frequency in relation to the degree of hypoxia. This response is attenuated with aging (Fukuda 1992) and it is related to the age-dependent structures and function modifications (Guenard 1998), including the basal reduction of oxygen requirements (Sohalet.al,1986, Gunnarsson et al, 1996).