ALMA, Mich. - Dr. John Davis, Alma College professor of exercise and health science, has conducted classes on some of the highest peaks in North America. In doing research on altitude physiology, Davis has taken Alma College students on several research trips to the Rocky Mountains in Colorado to study the acute and chronic effects of moderate altitude exposure on exercise and cardiovascular responses. In May he took another class to the mountains to research the effects of Ginko Biloba on acute mountain sickness and the physiological responses to a mini-hyperbaric chamber.

 

Effect of Ginkgo Biloba on Acute Mountain Sickness and Moderate Altitude Exercise

Many people experience lightheadedness, dizziness , and sickness in the stomach on ascent to high altitude. Described in the medical literature as acute mountain sickness (AMS), current approaches include a variety of prescription medications including acetylzolamide. Recently, a natural supplement (Ginkgo biloba) has been reported to improve symptoms in laboratory rats. Few studies have examined these responses in humans. In those studies, the results have been inconclusive.

Faculty and students from Alma College will be looking at the effects of ginkgo biloba on acute mountain sickness and exercise responses at high altitude using a double- blind controlled study. Results from this study will be used to determine the effectiveness of this supplement on AMS and subsequent exercise responses.

Physiological Responses to a Mini-hyperbaric Chamber

Upon ascent to high altitude, the barometric pressure decreases which sets off a cascade of effects including a decrease in the partial pressure of oxygen in the inspired air, a subsequent decrease in the partial pressure of oxygen in the arterial blood and impaired oxygen transport. In many instances, these changes leave an individual unable to function effectively at high altitudes. One of the severe consequences of these changes and the pulmonary vasoconstriction in the lungs that frequently occurs in some individuals is an accumulation of fluid in the lungs (pulmonary edema).

The most effective treatment is to get the individual back to a lower altitude. In some cases, this is not possible. An alternative is to use a mini-hyperbaric chamber like the Gamow bag. Clinically, the Gamow bag has been documented to be effective in treating high altitude disorders. However, few if any studies have looked at the physiological mechanisms involved with its use. The purpose of this research project will be to examine the physiological responses to hyperbaria induced by the Gamow bag. These responses will include a variety of cardiovascular and respiratory variables.