Effects of hypoxia on epididymal sperm parameters and protective role of ibuprofen and melatonin

Abstract

Hypobaric hypoxia is of interest due to an increase of human populations working at high altitude. Testicular damage is related to the physiological response (neoangiogenesis) to increased intrascrotal blood fl ow as temperature rises. Hypoxia is a stress factor with overproduction of reactive oxygen species (ROS). The effect of hypoxia in mice reproductive parameters is analyzed. Animals were exposed to simulated hypoxia of 4,200 meters above sea level (m.a.s.l.) in a chamber for 33.2 days, both to continuous (HH) or intermittent hypoxia (HI) with an intermittency period of 4 days hypoxia /4 days normoxia (500 m.a.s.l.). The anti-infl ammatory drug Ibuprofen was administered to a group of mice to control vasodilation and increased blood fl ow. Melatonin was administered to another group of mice as a potent ROS scavenger. Animals in both HH and HI exposure were compared to normoxic nontreated controls. There was a hematological response in hypoxia, with an increase in hematocrit and reticulocytosis. There was also increased teratozoospermia. This damage was more pronounced in HH than HI, suggesting that alternating normoxic periods permits compensation for the effects of hypoxia. In both hypoxia systems, the level of lipoperoxidation and the instability of DNA increased. In HH, there was a reduction of teratozoospermia in melatonin-treated mice. Ibuprofen presented a protective effect on the same parameters as melatonin with both HI and HH. The quality of sperm DNA, fragmentation, unpacking and DNA stability diminished. In conclusion, reproductive damage elicited by HH or HI was partially ameliorated by simultaneous treatment with antifl ogistic and/or antioxidant agents.

Melatonin Protects the Heart, Lungs and Kidneys from Oxidative Stress under Intermittent Hypobaric Hypoxia in Rats

“…The present study demonstrated that intermittent hypobaric hypoxia induces lipid peroxidation in testis and epididymis, as previously reported (Farias et al, 2010;Vargas et al, 2011). However, in the aforementioned studies melatonin did not have any effect with the doses used in contrary to other reports where melatonin had a protective role in testis and spermatogenesis of rats subjected to intermittent hypobaric hypoxia (Hartley et al, 2009;Bustos-Obregón et al, 2010;Vargas et al, 2011);Ahmad & Haldar (2010) as well as hamsters and rats, where melatonin seems to act directly on Leydig cells to suppress testosterone release in vitro.…”

“…However, in the aforementioned studies melatonin did not have any effect with the doses used in contrary to other reports where melatonin had a protective role in testis and spermatogenesis of rats subjected to intermittent hypobaric hypoxia (Hartley et al, 2009;Bustos-Obregón et al, 2010;Vargas et al, 2011);Ahmad & Haldar (2010) as well as hamsters and rats, where melatonin seems to act directly on Leydig cells to suppress testosterone release in vitro. When administered orally at 10 mg/kg bodyweight, melatonin has been described as a counteracting substance for testis and spermatogenesis damage in rats subjected to intermittent hypobaric hypoxia (Vargas et al, 2011). The present results showed that melatonin, with the doses given via intraperitoneal, had no protective effect in testis and epididymis.…”

“…Oxidative stress can be triggered by a series of endogenous and exogenous factors, exposure to intermittent hypobaric hypoxia being one of them (Farias et al, 2010;Vargas et al, 2011). Exposure to high altitudes is associated with an increase in the production of reactive oxygen species, which are generated during the phase of reoxygenation of intermittent hypobaric hypoxia and contributes to the physiological responses (Nanduri et al, 2008).…”

Juan Eduardo Bustos-Obregón (1937-2014)

“…Como también la evaluación del rol protector de distintas sustancias, tanto químicas como naturales sobre la función reproductiva de los organismos expuestos a los contaminantes descritos anteriormente. (Contreras et al, 1996., Bustos-Obregón et al, 1998., ., , 2010, 2013., Vargas et al, 2011, Bustos Obregón & Olivares 2012., Valenzuela et al, 2014.…”

The potential role of mesenchymal stem cells in a hypoxia model induced by sodium nitrite in testes of male albino rats

“…Greater testicular damage have been observed under continuous hypoxia. With intermittent hypoxia, lesions are less essential, suggesting that cycles of normoxia compensate the effects on the testicle (Vargas et al, 2011).…”