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Monserrato, Italy

Eberhard M.,Messina University | Ferlinz K.,Messina University | Alizzi K.,Section of General Physiology | Cacciato P.M.,Section of General Physiology | And 4 more authors.
Cellular Physiology and Biochemistry | Year: 2010

FTY720 is a potent anti-inflammatory drug known to trigger suicidal death or apoptosis of a variety of nucleated cells. Erythrocytes may similarly undergo suicidal erythrocyte death or eryptosis. Hallmarks of eryptosis include cell membrane scrambling and cell shrinkage, which are triggered by increase in cytosolic Ca2+ concentration and ceramide. The present study explored whether FTY720 stimulates eryptosis. Cell membrane scrambling was determined from annexin V-binding, cell shrinkage from forward scatter in FACS analysis, cytosolic Ca2+ concentration from Fluo3 fluorescence, ceramide formation from fluorescence-labeled antibody binding and hemolysis from the hemoglobin concentration in the supernatant. Within 48 hours exposure to FTY720 (10 μM) significantly increased annexin V-binding, decreased forward scatter and increased cytosolic Ca2+ concentration but did not significantly modify ceramide formation. The effects of FTY720 were significantly blunted in the nominal absence of extracelluar Ca2+. In conclusion, at toxic concentrations, FTY720 stimulates suicidal cell death, an effect at least partially due to stimulation of Ca2+ entry. © 2010 S. Karger AG Basel.

Muroni P.,Section of General Physiology | Crnjar R.,Section of General Physiology | Barbarossa I.T.,Section of General Physiology
Chemosensory Perception | Year: 2011

The hedonic valence of taste perception plays a crucial role in the control of responses related to feeding behaviour. Taste and olfaction perception can induce autonomic responses, such as heart rate variability (HRV), which are involved in the evoked emotional reactions. Analysis of HRV can help distinguish sympathetic from parasympathetic regulation of the sinoatrial node. In this work, we analysed the HRV associated with oral flavour stimuli with opposite hedonic dimension and assessed their sympathovagal balance. ECGs were recorded continuously on 11 men and 12 women before and after stimulations. Experiments were performed in two sessions for comparison. ANOVA highlighted the decreases and increases of sinusal rhythm associated with pleasant and unpleasant flavour stimulations, respectively. Time and frequency domain analysis of HRV indicates that bradycardia induced by the pleasant stimulus can be attributed to an increase in the vagal tone, whilst tachycardia evoked by the unpleasant stimulus denotes a reduction of the vagal tone in women and an increase of the sympathetic tone in men. In conclusion, our data suggest that the HRV analysis may represent a valuable tool for autonomic nervous system response characterization associated to the hedonic dimension of the complex flavour sensations induced by food and/or beverages. © Springer Science+Business Media, LLC 2011.

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