Uniqueness of dietary olive oil in stimulating aortic prostacyclin production in post-weanling rats

Abstract

Groups of weanling Sprague-Dawley rats developed from conception through gestation, and weanling periods on a formulated diet fed to the dams were continued on the same diet until sacrificed at 30 days of age. The diet groups consisted of control (5% corn oil, w w ) and experimental (15%, w w ) olive, safflower (hi-oleic and hi-linoleic), soy oil, and lard. The object of the study was to identify the effect of high and low fat content and differing proportions of polyunsaturated:saturated (P:S) and mono:polyunsaturated (M:P) fatty acids on arachidonate stimulated aortic prostacyclin (PGl 2) production (measured as 6-keto-PGF 1α). Neither the amounts of dietary fat or wide ranging P:S or M:P fatty acid ratio levels (P:S or M:P) affected PGl 2 production. PGl 2 production was, however, markedly enhanced (2×) in aortic segments from rats raised on diets containing olive oil. The unique stimulation of aortic PGl 2 production by the olive oil diet suggests an effect of the extraordinarily high M:P fatty acid ratio or, alternatively, of a still-to-be identified substance(s) in this ancient food.