title: Effects of hyaluronic acid on Ca(2+) influx, lactate dehydrogenase activity, and cyclic AMP synthesis in canine ejaculated sperm during In Vitro capacitation.
abstract: The effects of hyaluronic acid, which comprises the cumulus intercellular matrix, on Ca(2+) influx, lactate dehydrogenase (LDH) activity, and cyclic AMP synthesis in canine sperm during capacitation was investigated. Ejaculated sperm were collected from 10 Beagle dogs and the sperm were incubated for 4 hr in Eagle's MEM containing 10 microg/ml of hyaluronic acid. The percentages of actively motile sperm, hyperactivated sperm (HA-sperm), acrosome-reacted sperm (AR-sperm), and sperm labeled with fluoresceinated Ca(2+) indicator (Ca(2+)-labeled sperm) were evaluated to assess Ca(2+) influx into the sperm. LDH activity and cAMP concentration were measured in homogenized sperm. The mean percentages of motile sperm, HA-sperm, and Ca(2+)-labeled sperm in the MEM containing hyaluronic acid were higher than in the control medium (P<0.05, 0.05, and 0.01, respectively), but there was no difference between the percentages of AR-sperm. Mean LDH activity and mean cAMP concentration were also significantly higher than the control values (P<0.05). The percentages of HA-sperm correlated with those of Ca(2+)-labeled sperm (r(2)=0.810). The results indicate that hyaluronic acid increases Ca(2+) influx, LDH activity, and cAMP synthesis in canine ejaculated sperm during capacitation in vitro.
authors.affiliation: Department of Reproduction, Nippon Veterinary and Animal Science University, Musashino-shi, Tokyo 180-8602, Japan.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Kawakami
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Nishizono
authors.forename: Chihiro
authors.initials: C
authors.lastname: Miyata
authors.forename: Taichi
authors.initials: T
authors.lastname: Hirano
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Hori
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Tsutsui
mesh_terms: D020101:Acrosome Reaction / Q000187:drug effects; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D000242:Cyclic AMP / Q000096:biosynthesis*; D004285:Dogs / Q000502:physiology*; D006820:Hyaluronic Acid / Q000494:pharmacology*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D008297:Male; D008856:Microscopy, Fluorescence / Q000662:veterinary; D013075:Sperm Capacitation / Q000187:drug effects*; D013081:Sperm Motility / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism / Q000502:physiology
chemical_list: D006820:Hyaluronic Acid; D000242:Cyclic AMP; D007770:L-Lactate Dehydrogenase; D002118:Calcium