Rapeseed oil ingestion and exacerbation of hypertension-related conditions in stroke prone spontaneously hypertensive rats

• Published in: Toxicology (Amsterdam) Vol. 187; no. 2; pp. 205 - 216
• Main Authors: Naito, Yukiko, Nagata, Tomoko, Takano, Yuko, Nagatsu, Takashi, Ohara, Naoki
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 03.05.2003; Amsterdam Elsevier Science
• Subjects: Administration, Oral; Animals; Biological and medical sciences; Blood Pressure - drug effects; Brain - enzymology; Brain - pathology; Brassica napus oleifera; Erythrocyte Membrane - chemistry; Erythrocyte Membrane - metabolism; Fatty Acids, Monounsaturated - administration & dosage; Fatty Acids, Monounsaturated - pharmacology; Food toxicology; Glycine max; Hypertension - complications; Hypertension - mortality; Hypertension - physiopathology; Incidence; Kidney - enzymology; Kidney - pathology; Life span; Longevity - drug effects; Male; Medical sciences; Myocardium - enzymology; Myocardium - pathology; Na +, K +-ATPase; Phytosterols - blood; Plant Oils - administration & dosage; Plant Oils - pharmacology; Rapeseed (canola) oil; Rapeseed Oil; Rats; Rats, Inbred SHR; Sodium-Potassium-Exchanging ATPase - drug effects; Sodium-Potassium-Exchanging ATPase - metabolism; Soybean oil; Soybean Oil - administration & dosage; Soybean Oil - pharmacology; Stroke - etiology; Stroke prone spontaneously hypertensive rat (SHRSP); Toxicology; Rapeseed (canola) oil; Na +, K +-ATPase; Life span; Soybean oil; Stroke prone spontaneously hypertensive rat (SHRSP); Na+, K+-ATPase; Rat; Toxicity; Cardiovascular disease; Vegetable oil; K; Vascular disease; Na; Phytosterol; Mechanism of action; Cerebrovascular disease; Hypertension; Nervous system diseases; Stroke; Enzyme; Rodentia; Cerebral disorder; Rapeseed oil; Vertebrata; Mammalia; Animal; Central nervous system disease; Hydrolases; exchanging ATPase; Comparative study
• ISSN: 0300-483X; 1879-3185
• DOI: 10.1016/S0300-483X(03)00052-0

Two groups of 20 stroke prone spontaneously hypertensive rats (SHRSP) at 5 weeks old were fed a diet containing 10 w/w% rapeseed (canola) oil or soybean oil as the only dietary fat, and given drinking water containing 1% NaCl. Life span of the canola oil group (62±2 days) was shorter than that of the soybean oil group (68±3 days). Stroke-related symptoms were observed in every animal, but the onset of those in the canola oil group, at 47±1 days after starting the administration was earlier than that in the soybean oil group, 52±2 days. Incidence of cerebral hemorrhage was similar in these groups, and no differences were found between lesions of organs in the groups. In another experiment, two groups of ten SHRSP at 5 weeks of age were fed the defatted diet and given canola oil or soybean oil by gavage at 10 w/w% of consumed food for 4 weeks without NaCl loading. After the 4-week administration, mean systolic blood pressure in the canola oil group and the soybean oil group were 233±2 and 223±0.3 mmHg, respectively. Phytosterol levels in both plasma and erythrocyte membranes reflected those contained in the oils ingested. Na +, K +-ATPase activities in the brain, heart and kidney were enhanced in the canola oil group. These results indicate that promotion of hypertension-related deterioration in organs is likely to have relevance to the short life span in the canola oil group. Enhanced Na +, K +-ATPase activity by phytosterols in the oil ingested may play a role in these changes.