The respiratory function of blood in elderly and old age and the factors that determine it.

Autor: Korkushko, O. V., Ivanov, L. A., Pisaruk, A. V., Chebotarev, N. D.
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Zdroj: Human Physiology; Mar2009, Vol. 35 Issue 2, p163-169, 7p, 1 Diagram, 3 Charts, 3 Graphs
Abstrakt: Indices of pulmonary gas exchange, blood gases, the oxyhemoglobin dissociation curve, and intraerythrocytic metabolic parameters were analyzed in 62 apparently healthy elderly and senile subjects (60–92 years old) and 18 young healthy subjects (19–30 years old). PaO2 was found to decrease in elderly and senile subjects. Arterial hypoxemia in old age is caused by an increase in the alveoloarterial PO2 gradient, primarily as a result of the malcoordination of pulmonary ventilation and blood flow. A rightward compensatory shift of the oxyhemoglobin dissociation curve was observed, which was due to facilitated oxygen release in tissues owing to a pH decrease in erythrocytes (the Bohr effect). However, the facilitated oxygen release by oxyhemoglobin cannot compensate for the effect of factors deteriorating oxygen supply delivery to tissues, observed with aging, which is confirmed by the decrease in the partial pressure of oxygen in the venous blood of elderly and senile people, reflecting PO2 in tissues. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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