首页 | 本学科首页   官方微博 | 高级检索  
     


Sex differences in blood pressure response to intermittent hypoxia in rats
Authors:Hinojosa-Laborde Carmen  Mifflin Steven W
Affiliation:Department of Anesthesiology, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA. laborde@uthscsa.edu
Abstract:
Intermittent hypoxia is used to mimic the arterial hypoxemia that occurs during sleep apnea. The present study examined the blood pressure and heart rate responses to exposure to intermittent hypoxia in male rats and in female rats before and after ovariectomy. Rats were instrumented with telemetry transmitters and blood pressure, heart rate, and activity measured during 7 days of exposure to intermittent hypoxia (3 minutes of normoxia [21% oxygen] alternating with 3 minutes 10% oxygen between 8 am and 4 pm, remainder of day at normoxia). Blood pressure increased in males, females, and ovariectomized females in response to 7 days of intermittent hypoxia during the hours of exposure to hypoxia. Blood pressure increased less in intact females (average change in blood pressure 1.6+/-0.6 mm Hg, n=11) than in females studied after ovariectomy (5.1+/-1.1 mm Hg, n=6) or males (5.4+/-1.0 mm Hg, n=10). This elevated blood pressure persisted throughout the remainder of the day when the animals were not exposed to intermittent hypoxia and remained significantly attenuated in female rats. Ovariectomy abolished the protection against the elevated blood pressure response to intermittent hypoxia in females. Heart rate increased only in males, and only during the period of the day associated with intermittent hypoxia. Female rats were protected against this tachycardia independent of the ovarian hormones. These results indicate that females are protected from the hypertensive and tachycardia effects of intermittent hypoxia.
Keywords:
本文献已被 PubMed 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号