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Effects of Simulated Hypogravity and Diet on Estrous Cycling in RatsEnvironmental factors can disrupt ovulatory cycles. The study objective was to determine the effect of diet and simulated hypogravity on rat estrous cycles. Age 50 d Sprague-Dawley rats were randomly assigned to he fed either a purified or chow diet. Only normal cycling rats were used. Experimental rats (n=9-10/group) were kept as ambulatory controls (AC) or subjected to 40 d simulated hypogravity using a disuse atrophy hindlimb suspension (HLS) model. There was no effect on estrous cycles of AC fed either diet. At day 18, HLS rats fed either diet, had lengthened estrous cycles due to prolonged diestrus. HLS rats fed purified diet also had reduced time in estrus. Plasma estradiol was reduced in HLS rats fed purified diet but there was no effect on progesterone. This may have occurred because blood was collected from rats in estrus. Urinary progesterone collected during initial HLS was elevated in rats fed purified diet. In AC, corticosterone was elevated in chow vs purified diet fed rats. Differences were particularly striking following the application of a stressor with HLS/chow-fed rats displaying an enhanced stress response. Results emphasize the importance of diet selection when measuring endocrine-sensitive endpoints. HLS is a useful model for investigating the effects of environment on reproduction and providing insight about the impact extreme environment such as spaceflight on female reproductive health.
Document ID
20030018914
Document Type
Conference Paper
Authors
Tou, Janet C. (NASA Ames Research Center Moffett Field, CA United States)
Grindeland, Richard E. (NASA Ames Research Center Moffett Field, CA United States)
Baer, Lisa A. (NASA Ames Research Center Moffett Field, CA United States)
Wade, Charles E. (NASA Ames Research Center Moffett Field, CA United States)
Date Acquired
August 21, 2013
Publication Date
January 1, 2003
Subject Category
Life Sciences (General)
Meeting Information
FASEB 2003(San Diego, CA)
Funding Number(s)
PROJECT: RTOP 121-10-30
PROJECT: RTOP 121-10-50
PROJECT: RTOP 121-10-40
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.