37 research outputs found
A novel functional estrogen receptor on human sperm membrane interferes with progesterone effects.
Identification and characterization of a novel functional estrogen receptor on human sperm membrane that interferes with progesterone effects..
Extracellular calcium negatively modulates tyrosine phosphorylation and tyrosine kinase activity during capacitation of human spermatozoa.
Increased phosphorylation of AKAP by inhibition of phosphatidylinositol 3-kinase enhances human sperm motility through tail recruitment of protein kinase A
Tyrosine phosphorylation of the a kinase anchoring protein 3 (AKAP3) and soluble adenylate cyclase are involved in the increase of human sperm motility by bicarbonate
Nongenomic activation of spermatozoa by steroid hormones: facts and fictions.
International audienceThe rapid effects of steroids on spermatozoa have been demonstrated for the first time two decades ago. Progesterone (P), which is present throughout the female genital tract with peaks of levels in the cumulus matrix surrounding the oocyte, stimulates several sperm functions, including hyperactivation and acrosome reaction. These effects are mediated by an extranuclear pathway, as P stimulates an influx of calcium, the tyrosine phosphorylation of sperm proteins and other signalling cascades in a rapid manner. Whether these effects are receptor mediated and which receptors mediate these effects are still a matter of discussion despite all the efforts of the scientific community aimed at identifying them during the last 20 years. Although responsiveness to P is related to sperm fertilizing ability, the physiological role of P during the process of fertilization is discussed, and recent evidence points for a role of the steroid as a chemotactic agent for sperm. A similar situation applies for estrogens (E), which have been shown to induce direct effects on sperm by an extranuclear pathway. In particular, E appear to decrease acrosome reaction in response to P, exerting a role in ensuring an appropriate timing for sperm exocytosis during the process of fertilization