LETTER TO THE EDITOR
Re: Wet heat exposure: a potentially reversible cause of low semen quality in infertile men
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.
Publication Dates
-
Publication in this collection
02 July 2007 -
Date of issue
Apr 2007
