• Upregulation of heat shock proteins 70 and 90 induced by transient scrotal hyperthermia in mice
  • Azar Afshar,1 Mohammad-amin Abdollahi-far,2,*
    1. Department of Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
    2. Department of Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran


  • Introduction: It is now accepted that scrotal heat stress could adversely affect spermatogenesis. This high thermal condition can cause a reduced male fertility potential. Nowadays, there is limited data regarding the effect of transient scrotal hyperthermia on heat shock proteins 70 and 90 in mice. In the current study, we investigated the effects of scrotal hyperthermia on the expression of heat shock proteins, stereological parameters and semen quality in mice.
  • Methods: In this examination, a total of 18 healthy adult male NMRI mice were divided equally into two groups: control and scrotal hyperthermia. Scrotal heat stress was induced by placing the lower parts of mice bodies into the water bath for three consecutive days (43°C, 20 min/day)‎. Then, epididymis and testicular samples were collected for evaluation of sperm parameters, stereological study, mRNA, and protein expression of HSP70 and HSP90.
  • Results: Our results revealed that scrotal hyperthermia could strikingly increase the level of mRNA and protein expression of HSP70 and HSP90 in the samples. In addition, stereological parameters and semen quality significantly decreased in transient scrotal hyperthermia-induced mice compared to the control group.
  • Conclusion: The results of this study indicate that seminiferous tubules exhibit strong expression of heat shock proteins in response to hyperthermia, serving as a protective mechanism against cell apoptosis caused by thermal stress. Nevertheless, the observed decrease in sperm parameters and stereological measurements showing reduced cell numbers and tissue volume suggest that this protective factor was ineffective when hyperthermia occurred before puberty. Ultimately, such high temperatures experienced prior to puberty may lead to fertility issues during the postpubertal period.
  • Keywords: Hyperthermia, Heat Shock Protein, Testis, Male fertility, Heat stress