Dietary fat and cholesterol modification of rat abdominal aorta prostacyclin and leukotriene production (in vitro).

Groups of weanling male Sprague-Dawley rats fed formulated diets containing 15% by weight of corn oil (CO), linseed oil (LNO), or corn oil plus 1% cholesterol and 0.25% cholic acid (CH-CH) were sacrificed after 8 weeks and the aortas removed. Three mm length cross-sectional rings were cut from the distal abdominal aorta segment and incubated in either Tris buffer (pH 7.4, 37 degrees, 10 min.) for measurements of prostacyclin as 6-Keto-prostaglandin in F1 alpha (6-Keto-PGF1 alpha) or Tris buffer plus 10 microM ionophore A23187 for measurement of leukotriene C4 (LTC4) production using radioimmunoassay (RIA) procedures. 6-Keto-PGF1 alpha production was greater (p less than 0.01) in the CO than in the LNO and CH-CH fed rats by 54% and 40% respectively. LNO diets significantly lowered LTC4 production when compared to tissues from CO-fed rats (p less than 0.05). LTC4 production by tissues from the CH-CH-fed animals was lower than tissues from CO-fed animals, however, the difference failed to reach levels of significance because of data spread and the number of tissues. Tissues from the CH-CH-fed and LNO-fed rats were significantly different than those of the CO since LTC4 formation was high relative to 6-Keto-PGF1 alpha production (LTC4/6-Keto-PGF1 alpha). These results suggest distinctive effects of dietary fat and cholesterol on the syntheses of vasoactive eicosanoids that may be relevant to arterial tissue physiology and pathology.