The rate of @entity27376 reduction by electrons originating from @entity12931 in intact @entity95 spermatozoa was observed for control, high ionic strength (HIS) medium-treated, and HIS-seminal plasma-treated (HIS-SP) samples. The presence of @entity27376 in the incubation medium had no effect on @entity26 consumption, demonstrating the utility of @entity27376 as a nonperturbing probe of the @entity15401 redox state. The rate of @entity27376 reduction was significantly increased over control levels for sperm incubated in hypertonic medium and was correlated to a decrease in @entity26 consumption and a relative increase in @entity855 in the total @entity1708 pool. This increase in @entity27376 reduction in HIS sperm was reversed by treatment of sperm with seminal plasma, but seminal plasma had no effect on @entity26 consumption or relative amounts of @entity855 in the @entity1708 pool. These observations are consistent with state 3 respiration in control sperm and state 4 respiration in HIS- and HIS-SP-treated sperm. Arrhenius data were obtained for ejaculated and epididymal sperm subjected to a variety of treatments. Lines fitted to plots of Arrhenius data revealed that each treatment affected the activation energy and intercept relative to controls. Evidence is presented for a phase transition occurring at 13 degrees C based on changes in the rate of @entity27376 reduction by @entity15401 . It was noted that, above the phase transition, rate constants for the reaction were dependent upon both treatment and temperature, but below the transition the differential effects of treatment were no longer apparent. The present study has demonstrated that events taking place in the respiratory chain can be closely monitored by measuring @entity26 uptake and @entity27376 reduction, and that these events are affected by alterations in the sperm environment.

Alterations of @entity26 uptake and the redox state of XXXX in @entity95 sperm exposed to a variety of physiologic treatments.

@entity1708 :: ('CHEBI:61293', 'Chemical') :: ['adenine nucleotide'] @entity12931 :: ('MESH:D014451', 'Chemical') :: ['ubiquinone'] @entity15401 :: ('MESH:C003741', 'Chemical') :: ['ubiquinol'] @entity26 :: ('MESH:D010100', 'Chemical') :: ['oxygen'] @entity95 :: ('9986', 'Species') :: ['rabbit'] @entity27376 :: ('MESH:D014216', 'Chemical') :: ['TEMPONE'] @entity855 :: ('MESH:D000255', 'Chemical') :: ['ATP']
@entity12931 :: (MESH:D014451,Chemical) :: ['ubiquinone']
