stearates and Body-Weight

The toxicity of sodium stearoyl lactylate (SSL) was examined in Wistar rats fed diets containing 0, 1.25, 2.5, and 5% SSL for one year, equivalent to mean daily intakes of 558, 1115, and 2214 mg/kg/day in males and 670, 1339, and 2641 mg/kg/day in females, respectively. SSL was well tolerated at these dietary levels as evidenced by the absence of toxicologically significant changes in the general condition and appearance of the rats, survival, neurobehavioral endpoints, growth, feed and water intake, ophthalmoscopic examinations, hematology and clinical chemistry parameters, urinalysis, or necropsy findings. The occurrence of uterine endometrial stromal polyps was the only finding of potential significance. Given the frequent occurrence of these benign tumors in rats, wide variability in the reported incidence of this type of polyps in rats, the lack of statistical significance and lack of biological evidence to suggest a mechanism for the slightly greater incidence in the groups fed 2.5 and 5% SSL, it was concluded that the endometrial stromal polyps observed in females fed SSL were not related to treatment. The no observed adverse effect level (NOAEL) of SSL was placed at 5%, the highest dietary level tested (equivalent to 2214 mg/kg/day for males and 2641 mg/kg/day for females).

Topics: Animals; Body Weight; Carcinogenicity Tests; Dose-Response Relationship, Drug; Drinking; Eating; Emulsions; Endometrial Stromal Tumors; Female; Leukocyte Count; Male; Neoplasms; No-Observed-Adverse-Effect Level; Rats; Rats, Inbred F344; Sex Characteristics; Stearates; Survival; Urinalysis

We present here a study on the role of leptin in the regulation of lipogenesis by examining the effect of dietary macronutrient composition on lipogenesis in the leptin receptor-defective Zucker diabetic fatty rat (ZDF) and its lean litter mate (ZL). Animals were pair fed two isocaloric diets differing in their fat-to-carbohydrate ratio providing 10 and 30% energy as fat. Lipogenesis was measured in the rats using deuterated water and isotopomer analysis. From the deuterium incorporation into plasma palmitate, stearate, and oleate, we determined de novo synthesis of palmitate and synthesis of stearate by chain elongation and of oleate by desaturation. Because the macronutrient composition and the caloric density were controlled, changes in de novo lipogenesis under these dietary conditions represent adaptation to changes in the fat-to-carbohydrate ratio of the diet. De novo lipogenesis was normally suppressed in response to the high-fat diet in the ZL rat to maintain a relatively constant amount of lipids transported. The ZDF rat had a higher rate of lipogenesis, which was not suppressed by the high-fat diet. The results suggest an important hormonal role of leptin in the feedback regulation of lipogenesis.

Topics: Animals; Blood Glucose; Body Weight; Cholesterol; Deuterium; Diabetes Mellitus, Experimental; Dietary Carbohydrates; Dietary Fats; Energy Intake; Insulin; Leptin; Lipids; Male; Oleic Acid; Palmitates; Rats; Rats, Zucker; Stearates; Triglycerides

Male Sprague-Dawley rats were fed semipurified diets containing 12% fat and 0.4% cholesterol for 4 wk. The fats were palm oil, a high-stearate fat and canola oil; each of the latter two fat sources was substituted for palm oil in 4% (w/w) increments (i.e, 4, 8 and 12%) thus yielding 3 stearate-containing, 3 canola-containing, and a 12% palm oil diet. Stearate-fed animals exhibited significantly decreased food efficiency ratios, plasma total cholesterol, and liver cholesterol whereas the substitution of canola for palm oil did not consistently alter these parameters. Liver fatty acids generally reflected the composition of the dietary fat sources with the exception of significantly higher arachidonate observed in the stearate-fed rats.

Topics: Animals; Body Weight; Cholesterol; Dietary Fats; Eating; Fatty Acids, Monounsaturated; Lipids; Liver; Male; Palm Oil; Plant Oils; Rapeseed Oil; Rats; Rats, Sprague-Dawley; Stearates; Triglycerides

Topics: Animals; Body Weight; Chlorohydrins; Chromatography, High Pressure Liquid; Ethylene Chlorohydrin; In Vitro Techniques; Liver; Magnetic Resonance Spectroscopy; Male; Mass Spectrometry; Microsomes, Liver; Rats; Rats, Inbred Strains; Stearates; Stearic Acids; Time Factors

Magnesium stearate was fed to groups of 20 male and 20 female rats at levels of 0, 5, 10 and 20% in a semisynthetic diet for 3 months. Decreased weight gain was found in males in the 20% group. Urolithiasis was found in 8 males and in 7 females in the same group. Reduced relative liver weight was seen in males in the 10% and in the 20% groups, and an increased amount of iron was found in the livers of the 20% group. Nephrocalcinosis was reduced in females in the 20% group. In this experiment the no-effect-level is estimated to be 5% magnesium stearate in the diet, corresponding to 2500 mg/kg body wt/day.

Topics: Animals; Body Weight; Female; Kidney; Liver; Male; Nephrocalcinosis; Organ Size; Rats; Sex Factors; Stearates; Stearic Acids; Urinary Calculi

Eight saturated fatty acid esters were fed to male white rats for 30 days in a 1/81 fractional factorial experiment in which diets contained 12-38% of their total energy as lipid. Marked increases in food intake, feed efficiency, and weight gain were achieved when lipid provided 36% of diet energy, and when that lipid was more than half caproate, caprate, myristate, and/or stearate. Caproate was the only saturated fatty acid to increase plasma glucose levels. The feeding of stearate or caprylate decreased plasma and liver cholesterol. Caprate increased liver fat. The short-chain fatty acids (butyrate to myristate) increased the concentration of fat in the carcass.

Topics: Animal Nutritional Physiological Phenomena; Animals; Blood Glucose; Body Composition; Body Weight; Butyrates; Caproates; Caprylates; Cholesterol; Decanoates; Dietary Fats; Fatty Acids; Laurates; Lipid Metabolism; Liver; Male; Myristates; Palmitates; Rats; Stearates; Structure-Activity Relationship

Topics: Animals; Body Weight; Choline; Digestion; Fasting; Liver; Nitrogen; Proteins; Rats; Stearates