Sulfatide reduces leucocyte accumulation and reverts vascular failure in splanchnic artery occlusion shock

Studies on sulfatides by quadrupole ion-trap mass spectrometry with electrospray ionization: structural characterization and the fragmentation processes that include an unusual internal galactose residue loss and the classical charge-remote fragmentation

The structural characterization of sulfatides by collisional-activated dissociation (CAD) quadrupole ion-trap tandem mass spectrometric methods with electrospray ionization is described. When subjected to CAD in the negative-ion mode, the [M - H]- ions of sulfatides yield abundant structurally informative ions that permit unequivocal assignments of the long-chain base, and fatty acid constituent including the location of double bond. The identification of the position of the double bond on the fatty acyl substituent is based on the observation of the series of the ions arising from classical charge-remote fragmentation processes similar to those observed by high-energy CAD and by tandem quadrupole mass spectrometry. An unusual internal galactose residue loss due to a rearrangement process was also observed. The [M - H]- ions of sulfatides also dissociates to a ceramide anion, which undergoes consecutive fragmentation processes to yield ions informative for identification of the ceramide moiety and permits distinction the sulfatide with a sphingosine subclass from that with a sphinganine long-chain base subclass. The MS(2)-spectra of the sulfatide subclass with a sphingosine LCB and a alpha-hydroxy fatty acyl substituent (d18:1/hFA-sulfatide) are featured by the prominent ion sets of m/z 568, 550, 540, and 522, originated from a primary cleavage of the fatty acyl CO-CH(OH) bond, and are readily differentiable from those arising from the non-hydroxy sulfatide subclass (d18:1/nFA-sulfatide), in which the ion sets are of low abundance. The fragmentation pathways of sulfatides under low-energy CAD are proposed. The pathways are supported by the MS(2)- and MS(3)-spectra of various compounds, and of their H-D exchanged analogs.

Effect of sulfatide on acute lung injury during endotoxemia in rats

Experimental studies have shown that intrapulmonary leukocyte sequestration and activation is implicated in the pathogenesis of acute lung injury during endotoxemia. Selectins are involved in the adhesion of leukocyte to the endothelium. Sulfatide is recognized by P selectin and blocks this adhesion molecule. We studied the effects of sulfatide on endotoxin-induced lung damage in rats. Endotoxin shock was produced in male rats by a single intravenous (i.v.) injection of 20 mg/kg of Salmonella enteritidis lipopolysaccharide (LPS). LPS administration reduced survival rate (0%, 72 h after endotoxin challenge) decreased mean arterial blood pressure (MAP), produced leukopenia (Controls = 11,234+/-231 cells/mL, LPS = 4,567+/-123 cells/mL) and increased lung myeloperoxidase activity (MPO; a marker of leukocyte accumulation) in the lung (Controls = 0.35+/-0.1 U/g/tissue; LPS = 10+/-1.2 U/g/tissue). Furthermore LPS administration markedly impaired the concentration-response curves for acetylcholine and sodium nitroprusside in isolated pulmonary arterial rings. There was also an increased staining for P-selectin in the pulmonary arteries. Sulfatide treatment (10 mg/kg, 30 min. after LPS challenge), significantly protected against LPS-induced lethality (90% survival rate and 70% survival rate 24 h and 72 h after LPS injection), reduced LPS induced hypotension, reverted leukopenia (8,895+/-234 cells/ml) and lowered lung MPO activity (1.7+/-0.9 U/g/tissue). Furthermore sulfatide restored to control values the LPS-induced impairment in arterial pulmonary vasorelaxation and reduced P-selectin immunostaining. Our data indicate that sulfatide attenuates LPS-induced lung injury and protects against endotoxin shock.