Diets rich in n-9, n-6 and n-3 fatty acids differentially affect the generation of inositol phosphates and of thromboxane by stimulated platelets, in the rabbit.
We have studied the effects of semi-synthetic diets rich in either n-9 (olive oil, OO) or n-6 (corn oil, CO), or n-3 (fish oil, FO, as MaxEPA) fatty acids on the levels of major PUFA in platelet lipids, on the generation of inositol phosphates by [3H]inositol labelled platelets after stimulation with thrombin and of thromboxane B2 (TxB2) by platelet rich plasma (PRP) after stimulation with collagen. The predicted elevations of oleic (OA), linoleic (LA) and eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids were observed in platelet lipids of each animal group, but in the MaxEPA fed group accumulation of EPA was associated with depletion of linoleic acid (LA) rather than of arachidonic acid (AA). Basal levels of inositol-tris-phosphate (IP3) in platelets were lowest in the OO group and highest in the CO group, whereas the increment after thrombin stimulation (1 unit/ml NIH) was maximal in the OO group and minimal in the FO group. Instead, when generation of TxB2 by stimulated platelets was evaluated, no appreciable difference among the various groups could be detected, in accordance with the limited modifications of platelet AA content induced by the diets. The overall data indicate that dietary fatty acids modulate the pathway of inositol phosphate generation in rabbit platelets, independently of modifications of TxB2 production.
Medini
L
L
Institute of Pharmacological Sciences, University of Milan, Italy.
Colli
S
S
Mosconi
C
C
Tremoli
E
E
Galli
C
C
D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000097:blood; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D003314:Corn Oil / Q000494:pharmacology; D004041:Dietary Fats / Q000008:administration & dosage / Q000494:pharmacology*; D015118:Eicosapentaenoic Acid / Q000097:blood; D005227:Fatty Acids / Q000008:administration & dosage / Q000494:pharmacology*; D005395:Fish Oils / Q000494:pharmacology; D007295:Inositol Phosphates / Q000097:blood*; D007700:Kinetics; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000097:blood; D008297:Male; D000069463:Olive Oil; D010938:Plant Oils / Q000494:pharmacology; D011817:Rabbits; D013917:Thrombin / Q000494:pharmacology; D013929:Thromboxane B2 / Q000097:blood*
D001095:Arachidonic Acids; D004041:Dietary Fats; D005227:Fatty Acids; D005395:Fish Oils; D007295:Inositol Phosphates; D008041:Linoleic Acids; D000069463:Olive Oil; D010938:Plant Oils; D016718:Arachidonic Acid; D013929:Thromboxane B2; D003314:Corn Oil; D019787:Linoleic Acid; D015118:Eicosapentaenoic Acid; D013917:Thrombin