title: The Impact of Sperm Metabolism during In Vitro Storage: The Stallion as a Model.
abstract: In vitro sperm storage is a necessary part of many artificial insemination or in vitro fertilization regimes for many species, including the human and the horse. In many situations spermatozoa are chilled to temperatures between 4 and 10°C for the purpose of restricting the metabolic rate during storage, in turn, reducing the depletion of ATP and the production of detrimental by-products such as reactive oxygen species (ROS). Another result of lowering the temperature is that spermatozoa may be "cold shocked" due to lipid membrane phase separation, resulting in reduced fertility. To overcome this, a method of sperm storage must be developed that will preclude the need to chill spermatozoa. If a thermally induced restriction-of-metabolic-rate strategy is not employed, ATP production must be supported while ameliorating the deleterious effects of ROS. To achieve this end, an understanding of the nature of energy production by the spermatozoa of the species of interest is essential. Human spermatozoa depend predominantly on glycolytic ATP production, producing significantly less ROS than oxidative phosphorylation, with the more efficient pathway predominantly employed by stallion spermatozoa. This review provides an overview of the implications of sperm metabolism for in vitro sperm storage, with a focus on ambient temperature storage in the stallion.
authors.affiliation: Priority Research Centre for Reproductive Science, Discipline of Biological Sciences, Faculty of Science and IT, University of Newcastle, Callaghan, NSW 2308, Australia.
authors.forename: Zamira
authors.initials: Z
authors.lastname: Gibb
authors.affiliation: Priority Research Centre for Reproductive Science, Discipline of Biological Sciences, Faculty of Science and IT, University of Newcastle, Callaghan, NSW 2308, Australia.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Aitken
mesh_terms: D000818:Animals; D003080:Cold Temperature; D005307:Fertilization in Vitro; D006736:Horses; D006801:Humans; D008297:Male; D017382:Reactive Oxygen Species / Q000378:metabolism; D012662:Semen Preservation; D013081:Sperm Motility / Q000502:physiology*; D013094:Spermatozoa / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species