Dietary modulation of fatty acid composition of mast cell phospholipids does not affect histamine release induced by compound 48/80.

OBJECTIVE AND DESIGN

In the present study we determined the extent to which the degranulation process in mast cells was related to the fatty acid composition of membrane phospholipids.

MATERIAL

Peritoneal mast cells were isolated from Wistar rats (3 groups of 18 animals each), fed for 6 weeks diets which differed in their fatty acid compositions: (i) genuine salmon oil, abundant in (n-3) fatty acids, (ii) sunflower seed oil, rich in (n-6) fatty acids, particularly linoleic acid, and (iii) hydrogenated coconut oil, rich in saturated fatty acids.

METHODS

Mast cells (10(6)/ml) were stimulated with various concentrations of the mast cell-degranulating agent, compound 48/80 (0.1-10 micrograms/ml). The extent of mast cell degranulation was quantified by determination of histamine in the supernatants using HPLC techniques.

RESULTS

No differences in compound 48/80-induced histamine release between the three dietary groups for any of the concentrations of compound 48/80 tested were found. Analysis of variance followed by Tukey's method for multiple comparisons was used to evaluate the effect of changes in the dietary fat type.

CONCLUSION

These findings strongly suggest that in contrast to the formation of eicosanoids, the process of mast cell degranulation by a receptor-independent pathway is not controlled by the fatty acid composition of membrane phospholipids.