Nitric oxide production in living neurons is modulated by sphingosine: a fluorescence microscopy study.
An investigation was carried out into the possible effect of sphingosine (Sph) on nitric oxide (NO) production in living neurons. Differentiated granule cells were used in a dynamic videoimaging analysis of single cells labeled, simultaneously, with FURA-2 and the NO indicator 4,5-diaminofluorescein. The results demonstrate that Sph exerts a potent inhibitory effect on the Ca2+-dependent production of NO, without modifying the [Ca2+]i. The effect appears to be specific as neither ceramide nor Sph-1-phosphate had any effect on the NO and [Ca2+]i levels. The data demonstrate that Ca2+-dependent NO production is a specific Sph target in living granule cells, suggesting that this bioactive sphingoid plays a relevant role in neuronal NO signaling.
Viani
P
P
Department of Medical Chemistry and Biochemistry, Study Center for the Functional Biochemistry of Brain Lipids, University of Milan, via F.lli Cervi 93, LITA 20090 Segrate, Milan, Italy. paola.viani@unimi.it
Giussani
P
P
Ferraretto
A
A
Signorile
A
A
Riboni
L
L
Tettamanti
G
G
D000818:Animals; D019793:Fluorescein; D016257:Fura-2; D008856:Microscopy, Fluorescence / Q000379:methods*; D009474:Neurons / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013110:Sphingosine / Q000502:physiology*
C111205:4,5-diaminofluorescein; D009569:Nitric Oxide; D013110:Sphingosine; D019793:Fluorescein; D016257:Fura-2