cytellin and Stroke

The lymphatic recovery of radiolabeled sitosterol administered in various amounts to the stomach was almost the same between stroke-prone spontaneously hypertensive rats (SHRSPs), a strain having a missense mutation in ATP binding cassette transporter g5 (Abcg5), and Wistar rats, a normal strain. The results suggest that the mutation of Abcg5 in SHRSPs, compared with Wistar rats, did not influence the ability for intestinal sitosterol absorption regardless of the dose.

Topics: Absorption; Animals; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP-Binding Cassette Transporters; Dose-Response Relationship, Drug; Gastric Mucosa; Hypertension; Lipoproteins; Lymphatic System; Male; Mutation, Missense; Rats; Rats, Inbred SHR; Rats, Wistar; Sitosterols; Stroke

Analysis of sterol composition in serum, liver, adipose tissue, adrenals, and abdominal aorta demonstrated that the contents of plant sterols, campesterol and sitosterol, were evidently higher in WKY and stroke-prone spontaneously hypertensive (SHRSP) rats than in Wistar and WKA rats fed a diet containing a 0.5% plant sterol mixture. Lymphatic 24-hour recovery of 3H-sitosterol was about 2-fold higher in the WKY and SHRSP rats than in the WKA rats. Lymphatic absorption of 14C-cholesterol was also higher in WKY and SHRSP rats compared with WKA rats, but the difference was smaller than in the case of sitosterol. The remarkable increase of sitosterol absorption in WKY and SHRSP rats was observed between 9 and 24 hours after the administration. In SHRSP rats, lymphatic absorption of sitosterol between 0 and 3 hours was also higher than those in the other rat strains. Markedly less esterified 3H-sitosterol was detected in lymph than 14C-cholesterol in all strains, and in WKY and SHRSP rats, only a small increase in the esterified forms of sitosterol and cholesterol was observed. Although the incorporation of micellar 3H-sitosterol and 14C-cholesterol into intestinal brush border membranes was higher in SHRSP rats than in WKA rats, no difference was observed between WKY and WKA rats. These observations suggest that the incorporation into the brush border membranes and the esterification of sterols are not the major determinants for the hyperabsorption of sitosterol and cholesterol in SHRSP and WKY rats. Secretion of sitosterol and cholesterol in the bile of rats fed a plant sterol mixture was lower in SHRSP than in WKA rats. These results suggest that WKY and SHRSP strains deposit plant sterols in the body by enhancing the absorption and lowering the excretion of plant sterols. These strains of rats may be suitable models for studying mechanisms of differential absorption of various sterols.

Topics: Adipose Tissue; Adrenal Glands; Animals; Aorta, Abdominal; Bile; Cholesterol; Dietary Supplements; Genetic Predisposition to Disease; Hypolipidemic Agents; Intestinal Mucosa; Liver; Lymphatic System; Male; Microvilli; Organ Specificity; Phytosterols; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Rats, Wistar; Sitosterols; Species Specificity; Stroke

In recent studies, the life span of stroke-prone spontaneously hypertensive (SHRSP) rats was altered by a variety of dietary fats. It was relatively shorter in rats fed canola oil as the sole source of fat. The present study was performed to find out whether the fatty acid profile and the high content of sulfur compounds in canola oil could modulate the life span of SHRSP rats. SHRSP rats (47 d old, n = 23/group) were matched by body weight and systolic blood pressure and fed semipurified diets containing 10% canola oil, high-palmitic canola oil, low-sulfur canola oil, soybean oil, high-oleic safflower oil, a fat blend that mimicked the fatty acid composition of canola oil, or a fat blend high in saturated fatty acids. A 1% sodium chloride solution was used as drinking water to induce hypertension. After consuming the diets for 37 d, five rats from each dietary group were killed for collection of blood and tissue samples for biochemical analysis. The 18 remaining animals from each group were used for determining their life span. The mean survival time of SHRSP rats fed canola oil (87.4+/-4.0 d) was not significantly different (P > 0.05) from those fed low-sulfur canola oil (89.7+/-8.5 d), suggesting that content of sulfur in canola oil has no effect on the life span of SHRSP rats. The SHRSP rats fed the noncanola oil-based diets lived longer (mean survival time difference was 6-13 d, P < 0.05) than those fed canola and low-sulfur canola oils. No marked differences in the survival times were observed among the noncanola oil-based groups. The fatty acid composition of the dietary oils and of red blood cells and liver of SHRSP rats killed after 37 d of treatment showed no relationship with the survival times. These results suggest that the fatty acid profile of vegetable oils plays no important role on the life span of SHRSP rat. However, phytosterols in the dietary oils and in liver and brain were inversely correlated with the mean survival times,indicating that the differential effects of vegetable oils might be ascribed, at least partly, to their different phytosterol contents.

Topics: Animals; Brain Chemistry; Cholesterol; Dietary Fats, Unsaturated; Fatty Acids; Fatty Acids, Monounsaturated; Hypertension; Liver; Phytosterols; Rapeseed Oil; Rats; Rats, Inbred SHR; Sitosterols; Stroke; Survival Rate; Thiobarbituric Acid Reactive Substances; Vitamin E