Measurements of bovine sperm velocities under true anaerobic and aerobic conditions

Determination of optimal glucose concentration for microcalorimetric metabolic evaluation of equine spermatozoa

“…This effect was also reported for Leishmania (Mares-Guia et al, 1990) and mammalian cells (Wadsö, 1988). It induces the anaerobic metabolism by spermatozoa due to a low oxygen concentration (Gnaiger and Kemp, 1990;Krzyzoiak et al, 1999). Thus, the low energy production observed could reflect the change in the metabolic route from aerobic to anaerobic, when the cells were in the presence of a large substrate concentration (Fig 2).…”

“…Nevertheless, there are different conditions for the metabolism pathways among spermatozoa of various species. Boar and guinea pig spermatozoa can maintain motility only in the presence of O 2 , whilst human and bovine spermatozoa maintain their motility under aerobic and anaerobic conditions (Krzyzoiak et al, 1999). Thus, the metabolic efficiency of a system could be assessed from the ratio of oxygen consumed to the heat produced, in which the more efficient system displays the higher ratio (Gnaiger and Kemp, 1990;Bäckman et al, 1992).…”

“…Isothermal heat rates have been measured for the intact cells by both batch and flow calorimetry and relate to such properties as growth rates, thermodynamic parameters and effects of activators (Kemp, 1991;Krzyzoiak et al, 1999;Wadsö et al, 2001). As an alternative, the characterization of cellular metabolism microcalorimetry has been studied by the determination of the total sum of metabolic events in a cell population.…”

New insights into the nanometer-scaled cell-surface interspace by cell-sensor measurements

“…In summary, these experiments show that such a device not only allows direct interspace measurements but also an active manipulation of the interspace. c) ATP, which results from glycolysis, is used by cells as the energy source for the adhesion/morphology and mobility of cells, bacteria, and viruses [20][21][22][23][24][25]. Therefore, the IDESexperiment indicates that the adhesion/morphology is reduced for 1 h (C par increases).…”

Effects of Some Respiratory and Glycolytic Inhibitors on Mitochondrial Functionality in Bovine Semen

“…One example is 2-deoxy-D-glucose (DOG), a competitive inhibitor of glycolysis that targets hexokinase within the reaction glucose glucose 6-phosphate by competing with glucose during phosphorylation: the resulting product is DOG-6-phosphate which cannot be metabolized further [14,15]. When bovine sperm are re-suspended in a medium containing DOG and pyruvate and incubated at 37°C for 10 minutes, at least 70% of sperm cells remain motile, demonstrating that spermatozoa maintain motility utilizing mitochondrial ATP without employing the glycolytic pathway at this level [16] . By comparison, mouse sperm incubated similarly show a significant reduction in their motility, even in the presence of pyruvate and lactate [12,15]: this suggests that glycolytic ATP is crucial for sperm motility, or the decrease in motility might be due to utilization of mitochondrial ATP by DOG when phosphorylated with hexokinase.…”