Oleic acid versus linoleic and α-linolenic acid. different effects on Ca2+ signaling in rat thymocytes.

Background: Oleic acid is the principal fatty acid of olive oil composition and is reported to play a crucial role in its healthy aspects. However, the detailed mechanism of action is poorly understood.
Aims: This study aims to elucidate the role of oleic acid in calcium signaling in rat thymocytes, in comparison to linoleic and linolenic acid.
Methods: Fatty acids were applied to thymocytes isolated from wistar rats and loaded with Fura-2 to measure calcium signals.
Results: The main results showed a concentration-dependent increase in [Ca(2+)](i) induced by the 3 fatty acids. Raising the number of unsaturations resulted in greater increases. Two different pathways contributed to the increase induced by the polyunsaturated fatty acids: an IP(3)- independent release from the thapsigargin-sensitive stores and an extracellular calcium entry by econazole and nifedipine-insensitive channels. However, the OA-induced increases in [Ca(2+)](i) seemed to be due mostly to the Ca(2+) recruited from the intracellular stores.
Conclusion: This study demonstrates that the fatty acids tested induce increases in [Ca(2+)](i) in rat thymocytes, with differences in close relation to the degree of unsaturation. Such differences could be responsible for their different physiological action.
(Copyright © 2011 S. Karger AG, Basel.)