Sphingomyelin, SPM

The experimental procedure below describes the uptake of ciprofloxacin into sphingomyelin (SPM)/Chol LUVs. Drug delivery vehicles prepared from SPM/Chol often exhibit greater efficacy than those prepared from DSPC/Chol (13). Included is a description of the Bligh-Dyer extraction procedure (78), which involves partitioning the lipid and water-soluble drug into organic solvent and aqueous layers, respectively. This is necessary because lipid interferes with the ciprofloxacin assay. 

Most of the lipids of the neutral fraction were eluted at the solvent front when the chloroform/methanol/water solvent system, which is suitable for the separation of the acidic fraction, was used. We then tried solvent systems which can separate more hydrophobic lipids. Using the hexane/ ethyl acetate/ethanol/0.1% aqueous ammonia solvent system, we could separate phospholipids (Fig. 2B) and glycolipids (data not shown). A 5-mg amount of a neutral fraction from human brain lipids was applied to TC-CCC by using hexane/ethyl acetate/ethanol/0.1% aqueous ammonia (5 5 5 4). Phosphatidylcholine (PC), sphingomyelin (SPM), and lysophosphatidylcholine (lysoPC) were successively eluted. Phosphatidylethanolamine (PE) and lyso-phosphatidylethanolamine (lysoPE) and other minor phospholipid components were retained as the column contents with this solvent system. Cerebroside (fr. 28/36) and some... 

It should be emphasized that the SPM was completely separated into at least two groups (SPM 1 and SPM 11). It was reported that there are two forms of dihydrosphingomyelin (DHS) and sphingomyelin (SPM) in commercially available bovine brain SPM " SPM 1 and SPM 11 may correspond to these. TC-CCC is still in the prototype stage because there are many factors that still need to be improved, e.g., the flow volume, the flow rate, and the tube length, as previously described. In addition, the injection system and the detection system could be improved. If these elements can be enhanced, resolution may dramatically improve. 

The methods presented here describe the ability to characterize phosphatidylcholines (PCs), sphingomyelins (SPMs), phos-phatidylserines (PSs), and phosphatidylethanolamines (PEs) in the positive ion mode from rat brain tissue sections using imaging tandem MS and the creation of compound-specific images from full-scan MS and MS, while using MS for the final identification. The use of MS images for the separation of isobaric ions coupled with the ability to perform MS provides the means to identify isobaric species present in the tissue section. 

FIGURE 12.4 (A) Diagrammatic representation of the separation of major simple lipid classes on silica gel TLC — solvent system hexane diethylether formic acid (80 20 2) (CE = cholesteryl esters, WE = wax esters, HC = hydrocarbon, EEA = free fatty acids, TG = triacylglycerol, CHO = cholesterol, DG = diacylglycerol, PL = phospholipids and other complex lipids). (B) Diagrammatic representation of the separation of major phospholipids on silica gel TLC — solvent sytem chloroform methanol water (70 30 3) (PA = phosphatidic acid, PE = phosphatidylethanolamine, PS = phosphatidylserine, PC = phosphatidylcholine, SPM = sphingomyelin, LPC = Lysophosphatidylcholine). 

Figure 2 Coenzyme QIO (CoQiO) concentrations (CoQlO pgfg tissue) in various rat tissues at 6 and 12 h following the intravenous administration of 0.6 mg/kg of I C] CoQlO in emulsion prepared with either PC (phosphatidylcholine). PC + HCO-60 (hydrogenated castor oil), or SPM (sphingomyeline). Values at 6 h represent the mean of three to six rats. Values at 12 h represent the mean of two rats deviation from the mean was less than 20% in all cases.

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