Sources of diacylglycerols for phospholipid synthesis in rat liver

• The biosynthesis of molecular species of phosphatidylethanolamine and phosphatidylcholine in isolated rat liver parenchymal cells was studied with [32P]phosphate and [3H]glycerol as precursors. Addition to the cells of albumin-bound oleic or linoleic acid resulted in the synthesis of high proportions of dioleoyl- or dilinoleoyl-phospholipids, especially from labeled glycerol. The fact that these species contained a lower proportion of 32P than of 3H indicated that other diacylglycerols than those newly synthesized via phosphatidic acids took part in phospholipid synthesis. The composition of such diacylglycerols could be calculated and was found (a) to be essentially unaffected by the presence of oleic or linoleic acid during incubation, and (b) to be very similar to the mass composition of diacylglycerol units in the phosphatidyl-cholines. This suggests that they had been formed from the phosphatidylcholines, probably by the reversal of the cholinephosphotransferase (EC 2.7.8.2) reaction. These diacylglycerols contributed about 26 and 13 % of the total diacylglycerols incorporated into phosphatidylethanolamines and phosphatidylcholines, respectively.

Ämnesord

NATURVETENSKAP  -- Kemi -- Organisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Organic Chemistry (hsv//eng)

Nyckelord

Animals

Choline

Chromatography, Thin Layer

Diglycerides/metabolism

Fatty Acids/analysis

Fatty Acids, Unsaturated/analysis

Glycerides/metabolism

Glycerol/metabolism

Linoleic Acids/pharmacology

Liver/cytology

Male

Oleic Acids/pharmacology

Phosphatidic Acids/metabolism

Phosphatidylcholines/biosynthesis

Phosphatidylethanolamines/biosynthesis

Phospholipids/biosynthesis

Phosphotransferases/metabolism

Rats

Tritium

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)