Women at Altitude: Effects of Menstrual Cycle Phase and Alpha-Adrenergic Blockade on High Altitude Acclimatization
Final rept. 22 Sep 1995-21 Sep 1999
COLORADO UNIV HEALTH SCIENCES CENTER DENVER
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Three field studies were conducted under the award. The purpose of the first years studies was to examine the effect of the menstrual cycle on acclimatization to high altitude 4300 m in healthy, normally menstruating women. Twenty women were studied in the follicular and luteal phases of the menstrual cycle while residing at sea level and again in either the follicular or the luteal phase during the course of a sojourn in the US Army Research institute of Environmental Medicine USARIEM laboratory on the summit of Pikes Peak, CO 4300 m. The second years studies were conducted at USARIEM to determine the role of alpha-I adrenergic activity and its interaction with menstrual cycle phase in early altitude acclimatization. Fifteen women were exposed to an effective altitude of 4300 m in a hypobaric chamber for 52 hr on two occasions, once while being treated with an alpha -1 blocker prazosin and once while taking a placebo. Cycle phase was the same follicular or luteal during the blocked and unblocked studies for each subject. Sea level studies were performed prior to the altitude exposure. In year three, the purpose of the study was to determine the role of alpha-I adrenergic activity and its interaction with cycle phase during altitude acclimatization. Sixteen women were divided into two groups, half treated with an alpha-I blocker prazosin and the remaining half with placebo.
- Anatomy and Physiology
- Stress Physiology