Studies on cerebral sphingomyelin

Section: Methodsmentioning

confidence: 99%

Analysis of lipids from fresh and preserved adult human brains

Davison¹,

Wajda²

1962

“…Alkyl ether phospholipids have been recognized as constituents of the mammalian central nervous system, where they comprise about 2% of the total lipid P (Svennerholm & Thorin, 1960;Ansell & Spanner, 1961Dawson et al 1962). This content is of the same order as that found in the various sciatic nerves as well as the splenic nerve examined in the present study.…”

Section: Present Papermentioning

confidence: 99%

The polyphosphoinositides and other lipids of peripheral nerves

Sheltawy¹,

Dawson²

1966

103

1. A detailed lipid analysis of the peripheral nerves of the crab (claw, leg), lobster (claw, leg), cow (splenic), hen, rabbit, sheep and monkey (sciatic) is presented. 2. The so-called ;myelinic lipids', cholesterol, sphingomyelin, ethanolamine plasmalogen and phosphatidylserine, occurred in the highest proportion in the lipids of vertebrate myelinated nerves, whereas the percentage of lecithin was greatest in the lipids of non-myelinated nerve fibres of both vertebrates and invertebrates. 3. Triphosphoinositide was found in all nerves examined and its concentration in the extracted lipids supports the concept that it is predominantly localized in the myelin sheath. 4. In crustacean nerve 12-14% of the phospholipids was in the form of alkyl ether phospholipids, which in the lobster were approximately half choline-containing and half ethanolamine-containing.

“…This soyabean lipid fraction was homogenized and dialysed as described by Doery et al (1965) and kept at -20°C. Small batches were sonicated (see below) immediately before use in the phospholipase C assay.Phosphatidylinositol and sphingomyelin were purified from pig liver (Lapetina & Michell, 1973) and bovine brain (Ansell & Spanner, 1961) respectively. Lipid extracts from tissues and membrane preparations were also used as substrates, and these were prepared as described by Bramley et al (1971).…”

mentioning

confidence: 99%

“…Phosphatidylinositol and sphingomyelin were purified from pig liver (Lapetina & Michell, 1973) and bovine brain (Ansell & Spanner, 1961) respectively. Lipid extracts from tissues and membrane preparations were also used as substrates, and these were prepared as described by Bramley et al (1971).…”

mentioning

confidence: 99%

The action of phosphatidylinositol-specific phospholipases C on membranes

Low

Finean

1976

A phospholipase C prepared from lymphocytes readily hydrolysed pure phosphatidyl-inositol but was relatively ineffective against phosphatidylinositol in erythrocyte "ghosts" and rat liver microsomal fraction and also against sonicated lipid extracts from these membranes. In contrast, a phospholipase C prepared from Staphylcoccus aureus readily hydrolysed phosphatidylinositol in sonicated lipid extracts but had only low activity against purified phosphatidylinositol. Unlike the enzyme from lymphocytes, the S. aureus phospholipase C did not require Ca2+ for its activity and was inhibited by cations. The previously reported specificity of this enzyme was confirmed by our observation of hydrolysis of approx. 75% of the phosphatidylinositol in ox, sheep and cat erythrocyte "ghosts" together with no detectable effect on the major erythrocyte membrane phospholipids. The phosphatidylinositol of rat liver microsomal fraction was hydrolysed only to a maximum of 15%. Some preliminary experiments showed that approx. 60% of the phosphatidylinositol of ox or sheep erythrocytes could be hydrolysed without causing substantial haemolysis.