Prostaglandin-3 (PG-3)

: Any of various oxygenated unsaturated cyclic fatty acids of animals that are formed as cyclooxygenase metabolites especially from unsaturated fatty acids (as arachidonic acid) composed of a chain of 20 carbon atoms and that perform a variety of hormone-like actions (as in controlling blood pressure or smooth muscle contraction)

Prostaglandins are one of the three classes of eicosanoids. The other two are thromboxanes and leukotrienes. It is one of a number of hormone-like substances that participate in a wide range of body functions such as the contraction and relaxation of smooth muscle, the dilation and constriction of blood vessels, control of blood pressure, and modulation of inflammation. Prostaglandins are derived from a chemical called arachidonic acid, or AA.

Prostaglandin-3 is derived from the other essential fatty acid, linolenic acid, which can also be supplemented in the diet. But in order to complete the process of PG-3 production, linolenic acid must first be converted to two important intermediate fatty acids, EPA and DHA. The conversion of linolenic acid to EPA and then to DHA is actually a fairly inefficient process. It has been estimated that under the best of circumstances humans convert only about 2.7% of administered linolenic acid to EPA. Dietary saturated fat and cholesterol reduce this conversion. In addition, the final step, converting EPA to DHA, requires a specific enzyme that may not function appropriately in a large segment of the population.

Various fish oil products are available which are rich in preformed EPA and DHA eliminating the concern about the effectiveness of linolenic acid conversion.

Nov. 6 2005. ___________________
text provided by megan