[Significance and motivation of the clinical use of essential fatty acid derivatives, especially gamma-linolenic acid].

Although they were discovered in the first half of our century, essential fatty acids have started commanding clinical interest only during the last few years. Their vast possibilities for therapeutic use make basic knowledge of their chemical nature and physiologic significance a necessity. Essential fatty acids (linoleic and alpha-linolenic acid) are important not only in themselves but also as precursors of other polyunsaturated fatty acids. Besides, from some of these compounds an important series of substances is derived, such as prostaglandins, thromboxanes, prostacyclins, and leukotrienes. The sequence of enzymatic reactions on which the biosynthesis of these substances depends is altered in certain human pathologies. The key to the mechanism of action of some oils, such as evening primrose oil, is the fact that it contains as active principle the product of the blocked enzymatic reaction.