Abstract
Polyunsaturated fatty acid compositions were analyzed using gas liquid chromatograph (Shimazu, GC-R1A with solventless injector) equipped with a hydrogen flame ionization detector. A standard mixture of fatty acid was purchased from Applied Science, Inc. Two types of columns were used for the present measurement. One was a 300cm glass coiled column, 3mm i. d., packed with liquid of 5% Advance-DS, 5% Shinchrom E71, 5% or 10% Thermon 3000, the other was a glass capillary column (Shinwa Kako Co.) coated with films of DEGS (BCL type) or Thermon 3000 (WCOT type). Packed type column chromatography could not separate the fatty acid compositions of C20:0, C20:1, C20:3 and C20:4, whereas the glass capillary type column chromatography could clearly identify the individual compositions in the fatty acid. Especially, by means of the glass capillary column with Thermon 3000, the Δ8, 11, 14 C20:3 was separated from Δ11, 14, 17 C20:3. This indicates a possible usage of the latter composition as the internal standard in the gas liquid chromatography. Therefore, the glass capillary column chromatography seems to be more appropriate to qualitative and quantitative analysis of fatty acid compositions.
The above technique was applied to analyze blood samples of a healthy young man who was leaded with daily ingestion of canned mackerel meat rich in eicosapentaenoic acid (EPA) for 8 consecutive days. During the ingestion of mackerel meat, cholesterol, phospholipid, triglyceride and β-lipoprotein in the plasma showed a progessive decrease, while plasma HDL-cholesterol remained unchanged. Plasma arachidonic acid did not exhibit any significant change during. and after the meat ingestion. Platelet arachidonic acid, on the other hand, tended to increase for the second half of the ingestion period with its maximum value on the 2nd postingestion day. Plasma EPA reached its peak concentration on the 4th ingestion day.
A sharp increase in platelet EPA was observed during the ingestion period. Collagen induced platelet aggregation was reduced with the ingestion of mackerel meat. However, ADP induced platelet aggregation was not affected by mackerel meat.
These results lead us to the conclusion that EPA rich fish meat seems to play some roles in reducing the plasma lipid levels and in preventing the platelet aggregation.
