Circulation system in life processes and aging

ABSTRACT

The Dehydration Theory of Aging has been extended to the circulation system which has to transport as mush fluid daily as two to three times the weight of the body. The fluid quality and volume has to be precisely controlled. The system is put to tremendous strain in order to overcome the resistance from arterioles and micro-capillaries in the body which carry the fluids and from the glomeruli of the kidney. The latter provide a mechanism for ultrafiltration as well as reabsorption of 99% of the glomerular fluid to pass as urine. The resistance in transportation has been suggested to be due to cross-links formed between hydrophobic materials such as cholesterol and the muscle fibres, an example being the age pigment lipofuscin. Such cross-links introduced by small but significant quantities of aldehydes among collagen of blood vessels are suggested to be responsible for the rigidity of old blood vessels for the 60% reduction in the blood flow in the kidneys and for the reduction in flow in the peripheral vascular system during the aging process. The oxidative dehydration process of aging strike a balance in the circulation system just as much as in the respiratory system. This balance does not allow the accumulation of hydrogen ions which otherwise could give rise to acidosis, and this condition does not allow cross-link formation as is observed in the case of tanning the hide or dyeing the leathers. Excretion of surplus water, non-metabolized solutes in the diet and nitrogenous end products is a function of the kidney. It thus controls the osmolality of solutes and the hydration and dehydration processes. The carbonic anhydrase enzyme which plays a major role in catalyzing the absorption of carbon dioxide to form carbonic acid and its conversion to bicarbonate would lose its activity in the event of reduction of hydration level. This is suggested to be the major reason for the 60% reduction of kidney function during aging. Imbalance in the citrate and calcium ion transportation makes the cells more alkaline and favours calcium deposition. The crystalloids of calcium, magnesium, phosphate, oxalate and urates are present in the urine in supersaturated state. The presence of sequestering agents inhibits the growth and deposition of the crystalloids but their inhibitory effect is reduced in the acidic environment of the kidney or in stress situations and causes the deposition of renal calculi. The acidification of urine has also been considered in terms of the hydration and dehydration process and the circulation system in life processes has been suggested to support the hypothesis: