NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Effects of hypergravity on ovarian-hypophyseal function in antepartum and postpartum ratsBACKGROUND: Rats exposed to microgravity during the post-implantation phase of pregnancy had minimal alterations in ovarian and hypophyseal parameters during the antepartum and postpartum periods. In the current study, a similar parallel experimental design was employed to ascertain the effects of hypergravity on ovarian and hypophyseal function. HYPOTHESIS: We hypothesized that hypergravity exposure during the post-implantation stage of pregnancy would not alter antepartum and postpartum ovarian and hypophyseal function. METHODS: Pregnant rats were assigned to hypergravity (1.5 G, 1.75 G, or 2.0 G), rotational control, or stationary control groups (n = 10 each group) beginning on gestation day 11 and ending on day 20. Hypophyseal and ovarian analyses were conducted on 5 of the animals from each group at day 20. The remaining animals in each group were allowed to go to term and the same analyses were conducted 3 h postpartum. RESULTS: Hypergravity at all levels decreased the percent body mass gain from gestation day 11 to 20 (p < 0.05); however, the wet weight of the pituitaries and ovaries was not changed. There was no effect of hypergravity on the number of healthy or atretic antral follicles of any size at gestation day 20 or postpartum. The number of corpora lutea of pregnancy was decreased in all hypergravity groups, but the number of live fetuses at gestation day 20 or pups at term was not altered. Plasma concentrations of luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin, and progesterone were not changed at gestation day 20 or postpartum. Pituitary content of LH, FSH, and prolactin was not altered by hypergravity at gestation day 20, but LH content was significantly increased (p < 0.05) at 1.5 and 1.75 G postpartum. CONCLUSIONS: We conclude that hypergravity, up to and including 2.0 G, is compatible with maintenance of pregnancy and has minimal effects on hypophyseal parameters. Ovarian follicles are not altered by hypergravity, but corpora lutea may regress at a more rapid rate.
Document ID
20040087821
Acquisition Source
Ames Research Center
Document Type
Reprint (Version printed in journal)
Authors
Burden, Hubert W.
(Brody School of Medicine, East Carolina University Greenville, NC 27858, United States)
Zary, Joan T.
Hodson, Charles A.
Gregory, Heather L.
Baer, Lisa A.
Ronca, April E.
Date Acquired
August 21, 2013
Publication Date
February 1, 2003
Publication Information
Publication: Aviation, space, and environmental medicine
Volume: 74
Issue: 2
ISSN: 0095-6562
Subject Category
Aerospace Medicine
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Developmental Biology
NASA Center ARC

Available Downloads

There are no available downloads for this record.
No Preview Available