Studies with inhibitors showed that both human ZP3- and ZP4-induced acrosome reactions were protein kinase-C, protein
tyrosine kinase, T-type Ca(2+) channels, and extracellular Ca(2+) dependent. G-protein also participated in human ZP3- but not in ZP4-induced acrosome reaction. On the other hand, protein kinase-A and L-type Ca(2+) channels took part only in human ZP4-induced acrosome reaction. This manuscript describes for the first time the actions of purified native human ZP3 and ZP4 on acrosome reaction and spermatozoa-ZP binding.”
“Objective: Activated platelets release serotonin at sites of inflammation where it acts Buparlisib ic50 as inflammatory mediator and enhances recruitment of neutrophils. Chronic treatment with selective serotonin reuptake inhibitors (SSRI) depletes the serotonin storage ML323 pool in platelets, leading to reduced leukocyte recruitment in murine experiments. Here, we examined the direct and acute effects of SSRI on leukocyte recruitment in murine peritonitis.\n\nMethods: C57Bl/6 and Tph1-/- (Tryptophan hydroxylase1) mice underwent acute treatment with the SSRI fluoxetine or vehicle. Serotonin concentrations were measured by ELISA. Leukocyte rolling
and adhesion on endothelium was analyzed by intravital microscopy in mesentery venules with and without lipopolysaccharide challenge. Leukocyte extravasation in sterile peritonitis was measured by flow cytometry of abdominal lavage fluid.\n\nResults: Plasma serotonin levels were elevated 2 hours after fluoxetine treatment (0.70 +/- 0.1 mu g/ml versus 0.27 +/- 0.1, p = 0.03, n = 14), while serum serotonin did not change. Without further stimulation, acute fluoxetine treatment increased the number of rolling leukocytes (63 +/- 8 versus 165 +/- 17/0.04 mm(2)min(-1)) and decreased their velocity (61 +/- 6 versus 28 +/- 1 mu m/s, both p<0.0001, n = 10). In Tph1-/- mice leukocyte rolling was not significantly
influenced by acute fluoxetine treatment. Stimulation with lipopolysaccharide decreased rolling velocity and induced leukocyte adhesion, which was enhanced after fluoxetine pretreatment (27 +/- 3 versus 36 +/- 2/0.04 mm(2), click here p = 0.008, n = 10). Leukocyte extravasation in sterile peritonitis, however, was not affected by acute fluoxetine treatment.\n\nConclusions: Acute fluoxetine treatment increased plasma serotonin concentrations and promoted leukocyte-endothelial interactions in-vivo, suggesting that serotonin is a promoter of acute inflammation. E-selectin was upregulated on endothelial cells in the presence of serotonin, possibly explaining the observed increase in leukocyte-endothelial interactions. However transmigration of neutrophils in sterile peritonitis was not affected by higher serotonin concentrations, indicating that the effect of fluoxetine was restricted to early steps in the leukocyte recruitment. Whether SSRI use in humans alters leukocyte recruitment remains to be investigated.