Premium
Follicular fluid proteins stimulate nitric oxide (NO) synthesis in human sperm: A possible role for NO in acrosomal reaction
Author(s) -
Revelli Alberto,
Soldati Gianni,
Costamagna Costanzo,
Pellerey Ombretta,
Aldieri Elisabetta,
Massobrio Marco,
Bosia Amalia,
Ghigo Dario
Publication year - 1999
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/(sici)1097-4652(199901)178:1<85::aid-jcp11>3.0.co;2-y
Subject(s) - nitric oxide , sperm , sodium nitroprusside , acrosome reaction , follicular fluid , chemistry , nitric oxide synthase , citrulline , andrology , sperm motility , medicine , biochemistry , arginine , endocrinology , biology , microbiology and biotechnology , embryo , oocyte , amino acid
Nitric oxide (NO) is a free radical involved in the regulation of several functions of the male genitourinary system. It is produced by neurons and the endothelium and epithelia of reproductive system; it mediates penile erection and regulates sperm motility, viability, and metabolism. Here we show that human spermatozoa exhibit a detectable NO synthase (NOS) activity, measured both as ability of the intact sperm and cell lysate to convert L‐[ 3 H]arginine into L‐[ 3 H]citrulline and as 24 h accumulation of extracellular nitrite in intact sperm suspensions. NOS activity (identified as an endothelial isoform) was inhibited by L‐canavanine and N G ‐monomethyl‐L‐arginine, and nitrite accumulation was inhibited by the NO scavenger hemoglobin; both enzyme activity and nitrite production were increased by a 24 h incubation of spermatozoa with protein‐enriched extracts of human follicular fluid (PFF); a significant increase of citrulline synthesis was observed only after a 4 h incubation with 40% PFF, a time period during which acrosomal reactivity was significantly increased. PFF‐induced acrosomal reaction was inhibited by L‐canavanine and hemoglobin, and the NO donors sodium nitroprusside (SNP), S‐nitroso‐N‐acetyl‐penicillamine (SNAP), and DETA NONOate were able to increase the percentage of reacted spermatozoa. Our results suggest that NO synthesized by human sperm may play a role in follicular fluid–induced acrosomal reaction. J Cell Physiol 178:85–92, 1999. © 1999 Wiley‐Liss, Inc.