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Experiment K-7-16: Effects of Microgravity or Simulated Launch on Testicular Function in RatsFixed or frozen testicular tissues from five rats per group were analyzed by: subjective and quantitative evaluations of spermatogenesis; Northern-blot analysis for expression of selected genes; quantification of testosterone and receptors for LH; and morphometric analysis of Leydig cells. Based on observations of fixed tissue, it was evident that some rats in the flight and vivarium groups had testicular abnormalities unassociated with treatment, and probably existing when they were assigned randomly to the four treatment groups; the simulated-launch group contained no abnormal rat. Lesions induced in testes of caudal-elevation rats precluded discernment of any pre-existing abnormality. Considering rats without pre-existing abnormalities, diameter of seminiferous tubules and numbers of germ cells per tubule cross section were lower (E less than 0.05) in flight rats than in simulated-launch or vivarium rats. However, ratios of germ cells to each other, or to Sertoli cells, and number of homogenization-resistant spermatids did not differ from values for simulated-launch or vivarium controls. There was no effect of flight on normal expression of testis-specific hsp gene products, or evidence for production of stress-inducible transcripts of the hsp70 or hsp90 genes. Concentration of receptors for rLH in testicular tissue, and surface densities of smooth endoplasmic reticulum and peroxisomes in Leydig cells, were similar in flight and simulated-launch rats. However, concentrations of testosterone in testicular tissue or peripheral blood plasma were reduced (P less than 0.05) in flight rats to less than 20 percent of values for simulated-launch or vivarium controls. Thus, spermatogenesis was essentially normal in flight rats, but production of testosterone was severely depressed. Sequela of reduced androgen production on turnover of muscle and bone should be considered when interpreting data from mammals exposed to microgravity.
Document ID
19960028990
Acquisition Source
Ames Research Center
Document Type
Other
Authors
Amann, R. P.
(Colorado State Univ. Fort Collins, CO United States)
Clemens, J. W.
(Pennsylvania State Univ. University Park, PA United States)
Deaver, D.
(Pennsylvania State Univ. University Park, PA United States)
Folmer, J.
(Johns Hopkins Univ. Baltimore, MD United States)
Zirkin, B.
(Johns Hopkins Univ. Baltimore, MD United States)
Veeramachaneni, D. N. R.
(Colorado State Univ. Fort Collins, CO United States)
Grills, G. S.
(Columbia Univ. New York, NY United States)
Gruppi, C. M.
(Columbia Univ. New York, NY United States)
Wolgemuth, D.
(Columbia Univ. New York, NY United States)
Serova, L. V.
(Institute of Biomedical Problems Moscow, USSR)
Sapp, W. J.
(Tuskegee Inst. AL United States)
Williams, C. S.
(Tuskegee Inst. AL United States)
Date Acquired
August 17, 2013
Publication Date
September 1, 1994
Publication Information
Publication: US Experiments Flown on the Soviet Biosatellite Cosmos 2044
Subject Category
Life Sciences (General)
Accession Number
96N29585
Funding Number(s)
CONTRACT_GRANT: NCC2-12
CONTRACT_GRANT: NAG2-597
CONTRACT_GRANT: NAGw-1579
CONTRACT_GRANT: NIH-G12-RR-03059-01A1
CONTRACT_GRANT: NAG2-613
CONTRACT_GRANT: NAG2-612
CONTRACT_GRANT: NCC2-455
CONTRACT_GRANT: NGT-50315
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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