Altered responses of isolated aortic smooth muscle following chronic ingestion of palm oil diets in rats.
The responsiveness of the rat aorta after chronic consumption of 15% (wt/wt) fresh and thermally oxidized palm oil diets was studied under standard organ bath procedures. Aortic rings from the oxidized oil-fed group showed significantly (P < 0.05) enhanced vascular responses to noradrenaline and potassium chloride when compared with the control and fresh palm oil-fed groups. The maximum tensions were 285.10 +/- 30 mg/mg tissue weight for the oxidized oil-fed group and 148.98 +/- 36 mg/mg for the control in response to noradrenaline. The fresh oil-fed group produced maximum tension of 133.9 +/- 20 mg/mg which was not significantly different from the control. The trend was similar with potassium chloride. The maximum tensions were 206.31 +/- 25 mg/mg for the oxidized oil-fed group and 93.33 +/- 13 mg/mg for the control group. The fresh oil-fed group produced maximum tension of 109.31 +/- 7.8 mg/mg which was not significantly different from the control. Relaxation to acetylcholine was significantly (P < 0.01) attenuated in the aortic rings obtained from the oxidized palm oil-fed group when compared with the control and fresh palm oil-fed groups. The percentage maximum relaxations to acetylcholine were 28.1 +/- 6.7% in the oxidized oil-fed group, 71.4 +/- 6.0% in control and 78.2 +/- 6.0% in the fresh oil-fed groups. The relaxation in the fresh oil-fed group was not significantly different from control. These results suggest that functional changes occur in rat blood vessels after chronic consumption of thermally oxidized palm oil.
Owu
D U
DU
Department of Physiology, College of Medical Sciences, University of Calabar, Nigeria.
Orie
N N
NN
Osim
E E
EE
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects*; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects; D005224:Fats, Unsaturated / Q000737:chemistry; D006358:Hot Temperature; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D010084:Oxidation-Reduction; D000073878:Palm Oil; D010938:Plant Oils / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D014665:Vasodilator Agents / Q000494:pharmacology*
D004042:Dietary Fats, Unsaturated; D005224:Fats, Unsaturated; D010938:Plant Oils; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D000073878:Palm Oil; D011189:Potassium Chloride; D000109:Acetylcholine; D009638:Norepinephrine