Journal ArticleDOI
Variation in the cholesterol/phospholipid ratio in human spermatozoa and its relationship with capacitation
TLDR
The cholesterol/phospholipid ratio was determined for spermatozoa from eight men with normal semen parameters and shows a close correlation between the C/PL ratio and the rate of sperm capacitation as assessed by the hamster egg penetration test, supporting the notion that the loss or reduction of membrane cholesterol constitutes an important step of capacitation in human spermatoza.Abstract:
The cholesterol/phospholipid (C/PL) ratio was determined for spermatozoa from eight men with normal semen parameters. There was a close correlation between the C/PL ratio and the rate of sperm capacitation as assessed by the hamster egg penetration test. A lower C/PL ratio correlated with a faster capacitation time. This supports the notion that the loss or reduction of membrane cholesterol constitutes an important step of capacitation in human spermatozoa.read more
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Journal ArticleDOI
Current status of sperm cryopreservation: why isn't it better?
TL;DR: In this article, the authors reviewed aspects of sperm cryopreservation paralleled by events of capacitation and evaluated the possible roles of sperm membrane cholesterol, reactive oxygen species, and seminal plasma as mediators of sperm function.
Journal ArticleDOI
Novel signaling pathways involved in sperm acquisition of fertilizing capacity.
Pablo E. Visconti,V.A. Westbrook,Olga Chertihin,Ignacio A. Demarco,Susan B. Sleight,Alan B. Diekman +5 more
TL;DR: Recent progress is discussed in elucidating mechanisms which regulate sperm capacitation, which correlates with cholesterol efflux from the sperm plasma membrane, increased membrane fluidity, modulations in intracellular ion concentrations, hyperpolarization of the sperm Plasma membrane and increased protein tyrosine phosphorylation.
Journal ArticleDOI
Cholesterol efflux-mediated signal transduction in mammalian sperm: cholesterol release signals an increase in protein tyrosine phosphorylation during mouse sperm capacitation.
Pablo E. Visconti,XiaoPing Ning,Miguel W. Fornés,Juan G. Alvarez,Paula Stein,Stephanie A. Connors,Gregory S. Kopf +6 more
TL;DR: It is demonstrated that cholesterol release is associated with the activation of a transmembrane signal transduction pathway involving PK-A and protein tyrosine phosphorylation, leading to functional maturation of the sperm.
Journal ArticleDOI
Regulation of human sperm capacitation by a cholesterol efflux-stimulated signal transduction pathway leading to protein kinase A-mediated up-regulation of protein tyrosine phosphorylation
Joseph E. Osheroff,Pablo E. Visconti,Juan Pablo Valenzuela,Alexander J. Travis,Juan G. Alvarez,Gregory S. Kopf +5 more
TL;DR: It is demonstrated that bovine serum albumin (BSA) and NaHCO(3) are required for protein tyrosine phosphorylation in ejaculated human spermatozoa, and cholesterol release is associated with the activation of a signal transduction pathway involving protein kinase A and tyosine kinase second messenger systems, resulting in protein tyrosephosphorylation and capacitation.