Inhibition of in vitro capacitation of hamster spermatozoa by nitric oxide synthase inhibitors.
In an attempt to understand the role of nitric oxide(NO) in sperm capacitation, in the present study, hamster spermatozoa were used to evaluate the effects of NO on motility, viability, hyperactivation, capacitation and protein tyrosine and serine phosphorylation using specific inhibitors of nitric oxide synthase (NOS); namely L-NAME (N-nito-L-aginine methyl ester) and 7-Ni (7-nitroindazole). The results indicated that L-NAME inhibits sperm motility, hyperactivation and acrosome reaction where as 7-Ni inhibits only hyperactivation and acrosome reaction thus implying that NOS inhibitors exhibit subtle differences with respect to their effects on sperm functions. This study also provides evidence that NOS inhibitors inhibit sperm capacitation by their ability to modulate protein tyrosine phosphorylation. However, the inhibitors had no effect on the protein serine phosphorylation of hamster spermatozoa during capacitation. Thus, these results indicate that NO is required
Kameshwari
D B
DB
Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India.
Siva
A B
AB
Shivaji
S
S
D020101:Acrosome Reaction / Q000187:drug effects; D000818:Animals; D006224:Cricetinae; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007191:Indazoles / Q000494:pharmacology*; D008297:Male; D008647:Mesocricetus; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D010766:Phosphorylation; D011506:Proteins / Q000378:metabolism; D013075:Sperm Capacitation / Q000187:drug effects*; D013081:Sperm Motility; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000187:drug effects / Q000502:physiology*
D004791:Enzyme Inhibitors; D007191:Indazoles; D011506:Proteins; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; C080122:7-nitroindazole; D019331:NG-Nitroarginine Methyl Ester