Phosphatidylcholine metabolism for energy production in sea urchin spermatozoa.
Sea urchin spermatozoa use endogenous phosphatidylcholine (PC) to produce energy for swimming. The catabolism of PC was studied in Hemicentrotus pulcherrimus spermatozoa. Following incubation in sea water, the content of PC decreased and that of choline increased gradually, whereas phosphocholine maintained a constant level. Measurement of the radioactivity in metabolites converted from 1-palmitoyl-2-[1-14C]linoleoyl-PC, [choline-methyl-14C]dipalmitoyl-PC and 1-[1-14C]palmitoyl-lysophosphatidylcholine (LysoPC) showed that the major degradative pathway is PC----LysoPC----glycerophosphocholine----choline. 1-Palmitoyl-2-[1-14C]linoleoyl-PC and [1-14C]oleic acid were oxidized to 14CO2 in a cell-free system of spermatozoa. Sea urchin spermatozoa thus appear to quite likely obtain energy through the oxidation of fatty acid(s) from PC.
Mita
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Department of Biochemistry, Teikyo University School of Medicine, Tokyo, Japan.
Ueta
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D000818:Animals; D002474:Cell-Free System; D002794:Choline / Q000378:metabolism; D004734:Energy Metabolism; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D005997:Glycerylphosphorylcholine / Q000378:metabolism; D008244:Lysophosphatidylcholines / Q000378:metabolism; D008297:Male; D019301:Oleic Acid; D009829:Oleic Acids / Q000378:metabolism; D010084:Oxidation-Reduction; D010713:Phosphatidylcholines / Q000378:metabolism*; D010741:Phospholipases A / Q000378:metabolism; D010767:Phosphorylcholine / Q000378:metabolism; D012617:Sea Urchins / Q000378:metabolism*; D013094:Spermatozoa / Q000378:metabolism*
D005230:Fatty Acids, Nonesterified; D008244:Lysophosphatidylcholines; D009829:Oleic Acids; D010713:Phosphatidylcholines; D010767:Phosphorylcholine; D019301:Oleic Acid; D005997:Glycerylphosphorylcholine; D010741:Phospholipases A; D002794:Choline