Ghrelin attenuates heat-induced degenerative effects in the rat testis
ABSTRACT This study was conducted to examine the efficacy of ghrelin in prevention of deleterious effects of heat stress in rat testicular tissue. Forty five adult male rats were scheduled for this study and were divided equally into three groups: heat-saline, heat-ghrelin and control-saline. The scrota of heated-designed rats were immersed once in water bath at 43 °C for 15 min. Immediately upon heating, 2 nmol of ghrelin were given subcutaneously to heat-ghrelin animals every other day up to day 60 and physiological saline to the other two groups using the same method. The animals were sacrificed at 10, 30 and 60 days after heat treatment and their testes were taken for later photomicrograph and immunohistochemical analysis. Testicular histopathology revealed a significant reduction in the means of seminiferous tubules and Sertoli cell nucleus diameters as well as germinal epithelium height on day 10 in both heated groups. Furthermore, other testicular components including miotic index, spermatogenesis rate, presence of spermatocytes and volume densities were dramatically decreased following heat exposure. Notably, ghrelin caused a partial recovery in all of the above-mentioned parameters and accelerated testicular regeneration process by day 30 compared to the heat-saline group (P<0.05). Because of testicular progressive recovery, these indices were similar among groups on day 60 (P>0.05). However, immunohistochemistry evaluation for in situ detection of Bcl-2 protein did not exhibit any germ cells-positive of this factor among groups at different experimental days. In conclusion, the results of the present study indicate for the first time the novel evidences of ghrelin ability in attenuation of heat-induced testicular damage and also that ghrelin therapy may be useful as a suppressor of degenerative effects following testicular hyperthermia.
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ABSTRACT: This study was set to investigate whether the adverse effects of long-term copper (Cu) consumption on testicular tissue could be prevented by zinc (Zn) administration. Forty-five mature male rats were randomly divided into one control and two treatment groups. The first treatment group received copper sulfate (Cu experimental group). The second treatment group was given combined treatment of copper sulfate and zinc sulfate (ZC experimental group). Control animals received normal saline using the same volume. Five rats from each group were sacrificed on day 14, 28 and 56 from the beginning of treatments. Left testes were removed for histopathological and histomorphometrical evaluations. Morphometrically, diameter of seminiferous tubules and sertoli cells nuclei, epithelial height, meiotic index and the percentage of spermatogenesis in Cu groups showed significant decrease than those of the control groups (P < 0.05). A partial improvement was seen about the percentage of spermatogenesis and meiotic index (P < 0.05) in ZC groups, whereas a complete recovery was observed in the rest of parameters in ZC group after 56 days compared to the control group (P > 0.05). Results showed that long-term administration of Cu leads to histological impairments of testis and zinc supplementation might offset these damaging effects.Andrologia 11/2012; 46(2). DOI:10.1111/and.12047 · 1.17 Impact Factor
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ABSTRACT: Germ cell apoptosis have been recognized as an important event in order to regulate daily sperm production in humans and in animal models as well. Several studies in rat, mouse and monkeys have shown that testicular mild heat stress (43°C for 15 min) induces a massive increase in germ cell apoptosis along with oxidative damage and activation of diverse signaling pathways. In addition, heat stress produces a decrease in sperm viability, increase sperm damage and decrease embryo quality. In human, testis exposure to heat stress may result from occupational exposure, life style or clinical disorders including cryptorchidism or varicocele. Thus, in the past years researchers have focused on two major areas; the first is to find the molecular signaling pathway trigger by heat stress, and 2) to seek for new molecules with antioxidant abilities which may prevent germ cell apoptosis and/or to improve sperm performance. However, the link between heat stress and male infertility in humans still remains controversial. Here we critically review the available literature in human and animal models, and we propose a new modelTestis Anatomy, Physiology and Pathology, first edited by Yoshi, N and Norio I, 08/2012: chapter MOLECULAR BASIS OF HEAT STRESS DAMAGE IN MAMMALIAN TESTIS: pages 29; Nova., ISBN: 978-1-61942-739-6
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ABSTRACT: The effects of chronic heat stress on the reproductive system of rabbits have not been thoroughly examined. Therefore, we investigated the effects of heat stress on the reproductive performance of male Rex rabbits and documented the recovery process after stress withdrawal. Thirty age-matched, male Rex rabbits were placed into artificial climate chambers and randomly divided into three groups: control, heat stress, and recovery. Our results indicate that both libido of rabbit and sperm density were decreased significantly during the 9 weeks exposure to heat stress. Semen volume was mildly affected. Histomorphological and TUNEL assay results showed that chronic heat treatment adversely affected microscopic structure of the testes, and elevated the apoptosis of germ cells in the seminiferous tubules distinctly. However, these adverse effects induced by heat were transient as all measured parameters returned to control levels following the recovery period.Livestock Science 06/2012; 146(1):13–21. DOI:10.1016/j.livsci.2012.02.015 · 1.10 Impact Factor