%0 Journal Article
%T Rat Spermatogenesis Damage in Intermittent Hypobaric Hypoxia and the Protective Role of Melatonin. II: Testicular Parameters Da o de la Espermatog¨¦nesis en Rata en la Hipoxia Hipob¨¢rica Intermitente y Rol Protector de la Melatonina. II: Par¨¢metros Testiculares
%A Eduardo Bustos-Obreg¨®n
%A Rodrigo Castro-S¨¢nchez
%A Benito Ramos-Gonz¨¢lez
%A Leandro Torres-D¨ªaz
%J International Journal of Morphology
%D 2010
%I Sociedad Chilena de Anatom¨ªa
%X At present it is not clear if male fertility is affected by intermittent hypobaric hypoxia (IHH). This is an important issue since a large human population works over 3000 masl. This study analyzes testicular changes in adult Sprague Dawley rats after five cycles of IHH (7 day exposure to 4200 masl in a hypobaric chamber / 7 day at 500 masl). The animals were separated into groups of 8, one group was exposed to hypoxia (7 days), and the others to IHH for one to five cycles. Controls (500 masl) were examined at the beginning and at the end of the 70 experimental days. A duplicate set of rats treated with melatonin (supposedly protecting from hypoxia) was also examined, as were their controls, injected with 0,03% ethanol (melatonin solvent).Immunohistochemical and histometric analysis of testicular tissue were performed. Damage caused by IHH increases with time. Morphometry reveals an increase in tubular and luminal diameters and a reduction in epithelial height. Inmunohistochemistry for HIF-1alpha shows an increase with time, however the opposite happens with HSP-70. Spermatogenic cells submitted to comet assay present an increase of (+) cells. Melatonin counteracts all this damage, possibly due to its high efficiency as a reactive oxygen species scavenger. In conclusion, IHH exposure damages male reproductive function. Actualmente no se conoce claramente si la fertilidad masculina se afecta por la hipoxia hipobarica intermitente (IHH). Esto es de importancia porque una gran poblaci¨®n humana trabaja sobre 3000 metros sobre el nivel del mar (sml). Este trabajo analiza los cambios testiculares en ratas adultas Sprague Dawley luego de cinco ciclos de IHH (7 d¨ªas a 4.200 sml) en una camara hipobarica/7d¨ªas a 500 metros: Normoxia). Los animales de dividieron en grupos de 8; un grupo expuesto a hipoxia (7 d¨ªas ) y los otros a IHH por uno y hasta cinco ciclos. Los controles ( 500 sml) se analizaron al inicio y al final de los 70 d¨ªas experimentales. Un set duplicado de ratas tratadas con melatonina (considerada protectora de la Hipoxia) se examin¨® tambi¨¦n, asi como sus controles, inyectados con etanol 0,03% (solvente de la melatonina).Se realiz¨® an¨¢lisis histom¨¦trico e inmunohistoqu¨ªmico del tejido testicular. El da o causado por IHH aumenta con el tiempo. La morfometr¨ªa revel¨® un aumento de los di¨¢metros del t¨²bulo y lumen y una reducci¨®n de la altura del epitelio. La inmunohistoqu¨ªmica de HIF-1 alpha muestra aumento del n¨²mero de t¨²bulos positivos con el tiempo aunque lo opuesto ocurre para HSP-70. El ensayo de cometa muestra un aumento del n¨²mero de c¨¦lulas
%K Espermatog¨¦nesis
%K Hipoxia Hipob¨¢rica Intermitente
%K Protecci¨®n por melatonina
%K Spermatogenesis
%K intermittent hypobaric hypoxia
%K melatonin protection
%U http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022010000200034