NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Long-term (6-wk) hindlimb suspension inhibits spermatogenesis in adult male ratsThe International Space Station will allow extended habitation in space and long-term exposure to microgravity (microG). A concern is the impact of long-term microG exposure on the ability of species to reproduce. The model often used to simulate microG is rat hindlimb suspension (HLS), where the hindlimbs are elevated above the cage floor with a tail harness. Experiments described here are the first to examine the effect of long-term HLS on testicular function in adult male rats. Free-roaming (controls), animals with only the tail harnessed but hindlimbs in contact with the cage floor (TO), and HLS animals were tested for 6 wk. Cryptorchidism was prevented in TO and HLS animals by partial constriction of the inguinal canal with sutures. All parameters were compared at the end of the 6-wk experiment. Testicular weights and spermatogenesis were significantly reduced by HLS, such that no spermatogenic cells beyond round spermatids were present and epididymides were devoid of mature sperm. In many tubules, loss of all germ cells, except a few spermatogonia, resulting in histopathology similar to the Sertoli cell, was observed. Spermatogenesis appeared unaffected in control and TO animals. Sertoli and Leydig cell appearance, testosterone, luteinizing hormone, and follicle-stimulating hormone levels, and epididymal and seminal vesicle weight were unchanged by HLS. Cortisone was not elevated by HLS; thus stress may not be a factor. These results demonstrate that spermatogenesis is severely inhibited by long-term HLS, whereas testicular androgen production is not. These results have significant implications regarding serious effects of long-term exposure to microG on the reproductive capability of scrotal mammals, including humans.
Document ID
20040088473
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Tash, Joseph S.
(University of Kansas Medical Center Kansas City, Kansas 66160, United States)
Johnson, Donald C.
Enders, George C.
Date Acquired
August 21, 2013
Publication Date
March 1, 2002
Publication Information
Publication: Journal of applied physiology (Bethesda, Md. : 1985)
Volume: 92
Issue: 3
ISSN: 8750-7587
Subject Category
Aerospace Medicine
Funding Number(s)
CONTRACT_GRANT: U54 HD-33994
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Cell Biology
short duration
Flight Experiment
unmanned
Cosmos Project
Non-NASA Center

Available Downloads

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