title: Cyclical changes in sperm volume during in vitro incubation under capacitating conditions: a novel boar semen characteristic.
abstract: The osmotic reactivity of boar spermatozoa during incubation in vitro was studied using a hypo-osmotic swelling test in conjunction with electronic measurement of cell volume. Sperm populations showed fluctuations in both iso-osmotic cell volume and hypo-osmotic volume response that fitted mathematical models for periodicity. Significant differences of frequency and amplitude were observed during sperm incubation under capacitating conditions as compared with those under non-capacitating conditions. In addition, different boars showed specific differences in their fluctuation characteristics under capacitating conditions. During incubation under capacitating conditions, a decrease in osmotic reactivity was observed that correlated with a decrease in motility, while the absolute value of the earliest maximum of the osmotic-induced response correlated with an increase in the proportion of discharged acrosomes. The time course of the cyclical behaviour of osmotic reactivity may be a useful parameter for assessing boar sperm response to capacitating conditions.
authors.affiliation: Institute for Reproductive Medicine, School of Veterinary Medicine Hannover, Buenteweg 15, 30559 Hannover, Germany.
authors.forename: A M
authors.initials: AM
authors.lastname: Petrounkina
authors.forename: R A
authors.initials: RA
authors.lastname: Harrison
authors.forename: R
authors.initials: R
authors.lastname: Petzoldt
authors.forename: K F
authors.initials: KF
authors.lastname: Weitze
authors.forename: E
authors.initials: E
authors.lastname: Töpfer-Petersen
mesh_terms: D000818:Animals; D048429:Cell Size; D002478:Cells, Cultured; D008297:Male; D009995:Osmosis; D010507:Periodicity; D012662:Semen Preservation / Q000379:methods* / Q000662:veterinary; D013075:Sperm Capacitation; D013094:Spermatozoa / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D013552:Swine / Q000502:physiology*