Cytidine (5') diphosphocholine-induced decrease in cerebral platelet activating factor is due to inactivation of its synthesizing enzyme cholinephosphotransferase in aged rats.
Levels of cerebral platelet activating factor (PAF) result from the balance between the activities of its synthesizing enzyme dithiothreitol (DTT)- insensitive cholinephosphotransferase and its degradative enzyme PAF acetylhydrolase. Cerebral fractions of aged rats (19 months) displayed higher levels of PAF acetylhydrolase isoenzymes (P<0.05; n=4), unaltered levels of DTT-insensitive cholinephosphotransferase and lower PAF levels than young animals (2 months). Cerebral fractions of aged rats treated with cytidine (5') diphosphocholine displayed lower DTT-insensitive cholinephosphotransferase (55% after 8 days of treatment with 350 mg/kg per day, P<0.05; n=4), unaltered levels of PAF acetylhydrolase and lower PAF levels than untreated control animals. Thus our data would indicate that decrease of cerebral PAF may be attributed to an activation of PAF acetylhydrolase in ageing, and to an inactivation of DTT-insensitive cholinephosphotransferase in cytidine (5') diphosphocholine treated animals.
Giménez
R
R
Department of Biochemistry, School of Pharmacy, University of Barcelona, Avenida Diagonal 643, 08028, Barcelona, Spain.
Aguilar
J
J
D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase; D000375:Aging / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology; D002540:Cerebral Cortex / Q000187:drug effects / Q000201:enzymology*; D003566:Cytidine Diphosphate Choline / Q000378:metabolism* / Q000494:pharmacology; D002798:Diacylglycerol Cholinephosphotransferase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D005526:Food, Formulated; D007527:Isoenzymes / Q000187:drug effects / Q000378:metabolism; D008297:Male; D018697:Nootropic Agents / Q000378:metabolism* / Q000494:pharmacology; D010741:Phospholipases A / Q000378:metabolism; D010972:Platelet Activating Factor / Q000096:biosynthesis* / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D020521:Stroke / Q000201:enzymology / Q000503:physiopathology; D013347:Subcellular Fractions / Q000187:drug effects / Q000201:enzymology
D007527:Isoenzymes; D018697:Nootropic Agents; D010972:Platelet Activating Factor; D003566:Cytidine Diphosphate Choline; D002798:Diacylglycerol Cholinephosphotransferase; D010741:Phospholipases A; D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase