1.- Maximum human life span reaches its utmost in populations living in high altitude and mountain areas.  Until now there have been no reasonable scientific explanations to this longevity phenomena. The hypothesis on ageing presented here  intends to prove that the exceptional long life-span found in  mountain areas is mainly due to the low atmospheric oxygen pressure found at higher altitudes.

2.- Atmospheric oxygen is represented mainly by molecular oxygen, a stable free radical, and superoxide, a highly reactive free radical. The superoxide in brain cells, induces auto-oxidation of dopamine, and the lethal compound 6-hydroxydopamine, is formed with release of toxic hydrogen peroxide. In defense, brain cells absorb the hydrogen peroxide by producing melanin, a black pigment observed in the substantia nigra. Damage to the dopaminergic system is an established cause of Parkinson's disease and many of the symptoms that characterize old age.

3- Surplus of oxygen in the brain, specifically superoxide, is lethal to cells secreting the neurotransmitter dopamine. The fact that 13% of  dopaminergic cells die each decade after age 45, clearly means that  detrimental oxidations occur in the dopaminergic system, I propose that this is caused by high oxygen pressure.

4.- Secretion of growth hormone is dependent on cells secreting dopamine.  Oxygen deleterious effects on the dopaminergic system will reduce the secretion of  human growth hormone. In humans, cessation of the period  of growth is directly related to the secretions of growth hormone. Consequently, high atmospheric oxygen concentrations cause  damage to cells secreting dopamine, which cause decrease in growth hormone secretion and cessation of growth. In other words, cessation of growth is   directly related to the concentration of oxygen in the atmosphere. (Color Plate 5, Page 66)

5.- Ageing in accordance with the second law of thermodynamics is characterized by increases in entropy. Cessation of growth is equivalent to an increase in entropy, which is an unfavorable situation  that signals the initiation of senescence.

6.- The main conclusion of this dissertation is that the process of ageing could be  modulated by alterations in atmospheric oxygen.   The arguments presented in this hypothesis clearly  prove that the process of human ageing although irreversible, could be significantly delayed through  correct manipulations of the atmospheric oxygen pressure.

The above mentioned facts and ideas have been presented to encourage  new trials in gerontology, in which experimentation animals be tested for  life span, when living in artificially created  environments, with differing chemical air composition. 

My hypothesis intends to prove that oxygen plays a fundamental role.

Higher oxygen pressure should shorten life span.

Low  oxygen pressure should increase  maximum  life  span.

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