Rapeseed oil ingestion and exacerbation of hypertension-related conditions in stroke prone spontaneously hypertensive rats.
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.
Naito
Yukiko
Y
Laboratory of Pharmacology, Hatano Research Institute, Food and Drug Safety Center, Ochiai 729-5, Hadano, Kanagawa 257-8523, Japan.
Nagata
Tomoko
T
Takano
Yuko
Y
Nagatsu
Takashi
T
Ohara
Naoki
N
D000284:Administration, Oral; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001921:Brain / Q000201:enzymology / Q000473:pathology; D004910:Erythrocyte Membrane / Q000737:chemistry / Q000378:metabolism; D005229:Fatty Acids, Monounsaturated / Q000008:administration & dosage / Q000494:pharmacology*; D006973:Hypertension / Q000150:complications* / Q000401:mortality / Q000503:physiopathology; D015994:Incidence; D007668:Kidney / Q000201:enzymology / Q000473:pathology; D008136:Longevity / Q000187:drug effects; D008297:Male; D009206:Myocardium / Q000201:enzymology / Q000473:pathology; D010840:Phytosterols / Q000097:blood; D010938:Plant Oils / Q000008:administration & dosage / Q000494:pharmacology*; D000074262:Rapeseed Oil; D051381:Rats; D011918:Rats, Inbred SHR; D000254:Sodium-Potassium-Exchanging ATPase / Q000187:drug effects / Q000378:metabolism; D013024:Soybean Oil / Q000008:administration & dosage / Q000494:pharmacology; D020521:Stroke / Q000209:etiology*
D005229:Fatty Acids, Monounsaturated; D010840:Phytosterols; D010938:Plant Oils; D000074262:Rapeseed Oil; D013024:Soybean Oil; D000254:Sodium-Potassium-Exchanging ATPase