Open AccessRegulation of hyperactivation of hamster spermatozoa by progesterone
Author(s) -
NOGUCHI TAKAO,
FUJINOKI MASAKATSU,
KITAZAWA MASAFUMI,
INABA NORIYUKI
Publication year - 2008
Publication title -
reproductive medicine and biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.005
H-Index - 22
eISSN - 1447-0578
pISSN - 1445-5781
DOI - 10.1111/j.1447-0578.2008.00202.x
Subject(s) - hyperactivation , sperm , tyrosine phosphorylation , capacitation , sperm motility , phosphorylation , hamster , andrology , biology , motility , acrosome reaction , microbiology and biotechnology , medicine , endocrinology , chemistry
Aim: Although it is accepted that progesterone (P) induces acrosome reaction through non‐genomic regulation, it is not well known if P also affects hyperactivation of sperm. Methods: Hamster spermatozoa were hyperactivated by incubation for 4 h on modified Tyrode's albumin lactate pyruvate medium and recorded on a DVD via a charge‐coupled device camera attached to a microscope with phase‐contrast illumination and a small CO 2 incubator. Phosphorylation of proteins was detected by western blotting using antiphosphotyrosine antibodies. Results: Sperm hyperactivation was significantly increased and accelerated by a non‐genomic signal of P. Although acceleration of motility of hyperactivated sperm occurred with 10, 20 and 40 ng/mL P, the most effective concentration was 20 ng/mL. Progesterone also significantly increased 80‐kDa tyrosine phosphorylation of sperm proteins. Both extracellular Ca 2+ and albumin were essential for sperm hyperactivation, and the former was also essential for maintaining sperm flagellar movement. Moreover, phospholipase C (PLC) was associated with the regulation of hyperactivation by P. Conclusion: It is likely that P regulates sperm hyperactivation by a non‐genomic signal in relation to tyrosine phosphorylation and PLC. (Reprod Med Biol 2008; 7 : 63–74)