| RE:
WET HEAT EXPOSURE: A POTENTIALLY REVERSIBLE CAUSE OF LOW SEMEN QUALITY
IN INFERTILE MEN
(
Download pdf )
SHAI SHEFI, PHIROZ
E. TARAPORE, THOMAS J. WALSH, MARY CROUGHAN, PAUL J. TUREK
Departments
of Urology, Obstetrics, Gynecology and Reproductive Science, and Epidemiology
and Biostatistics, University of California San Francisco, San Francisco,
California, USA
Int
Braz J Urol, 33: 50-57, 2007
To the Editor:
Dry
and wet heat differ mainly in the speed of energy transfer, as heat transfer
by convection and contact in water is increased than in air, and because
heat dissipation by sweat evaporation is blocked into the water (1), thus
this study express the concern of recreational immersion in hot water
over male reproductive health.
The current article by Shefi and colleagues
proves the reversible effect of this spermatogenic harm through the comparison
of total motile count during wet heat exposure and after cessation. Heat
effects over sperm quality are like to happen within 3 days of exposure
(2) and it seems to be reversible as in heat injury from other sources
(3).
In spite of the important results demonstrated,
this study does not privileges some issues as sperm DNA fragmentation,
and other molecular pathways, like heat shock proteins (Hsp) expression.
Heat stress produced by cryptorchidism and varicocele is well characterized
as a DNA fragmentation inducer (4,5) even when normal morphology is observed
(5), and may affect ART outcomes (4). Also, Hsps reestablish a homeostatic
mechanism and equilibrium between protein synthesis and degradation in
the cells (6) and differential expression of HSP70 and HSP90 was shown
in the heat-induced stress (7).
Investigation of these underlying factors
process should be considered in further studies intending to elucidate
the mechanisms and differences of wet heat gonadotoxicity and induced
infertility.
References
1. Schimidt-Nielsen K: Temperature regulation. In: Schimidt-Nielse K (ed.).
Animal Physiology: Adaptation and Environment. Cambridge, University Press,
1997, pp.607.
2. Ren L, Medan M, Ozu M, Li C, Watanabe G, Taya K: Effects of experimental
cryptorchidism on sperm motility and testicular endocrinology in adult
male rats. J Reprod Develop. 2006; 52: 219-28.
3. Pasqualotto FF, Lucon AM, Goes PM, Sobreiro BP, Hallak J, Pasqualotto
EB, et al.: Semen profile, testicular volume, and hormonal levels in infertile
patients with varicoceles compared with fertile men with and without varicoceles.
Fertil Steril. 2005; 83: 74-7.
4. Banks S, King AS, Irvine DS, Saunders PTK: Impact of a mild scrotal
heat stress on DNA integrity in murine spermatozoa. Reproduction. 2005;
129: 505-514.
5. Bertolla RP, Cedenho AP, Hassun Filho PA, Lima SB, Ortiz V, Srougi
M: Sperm nuclear DNA fragmentation in adolescents with varicocele. Fertil
Steril. 2006; 85: 625-8.
6. Shi Y, Mosser DD, Morimoto RI: Molecular chaperones as HSF1-specific
transcriptional repressors. Genes Dev. 1998; 12: 654-66.
7. Lima SB, Cenedeze MA, Bertolla RP, Hassun Filho PA, Oehninger S, Cedenho
AP: Expression of the HSPA2 gene in ejaculated spermatozoa from adolescents
with and without varicocele. Fertil Steril. 2006; 86: 1659-63.
Dr.
Pericles A. Hassun Filho
Department of Obstetrics & Gynecology
1150 W. Medical Center Drive
University of Michigan
Ann Arbor, Michigan, 48109-0617, USA
E-mail: pericles.hassun@gmail.com
REPLY BY THE AUTHORS
We
agree that the functional capacity of sperm should be evaluated after
wet heat exposure to understand if the mechanisms of impairment are similar
to that described for other forms of heat stress.
|