Myocardial lesions in rats fed rapeseed oil. I. Influence of strain of rats

1977 ◽  
Vol 55 (2) ◽  
pp. 258-264 ◽  
Author(s):  
H. W. Hulan ◽  
J. K. G. Kramer ◽  
A. H. Corner
Keyword(s):  
Fatty Acid Composition ◽  
Rapeseed Oil ◽  
Corn Oil ◽  
The Other ◽  
Sprague Dawley ◽  
High Incidence ◽  
Two Factors ◽  
Ad Libitum ◽  
Different Strains ◽  
Myocardial Lesions

The influence of strain of rat on the development of myocardial lesions was investigated in an experiment which included two factors: strain (Wistar, Sherman, Chester Beatty (Hooded), and Sprague–Dawley from two sources designated Sprague–Dawley A, Sprague–Dawley C) and diet (5% corn oil, 20% corn oil, and 20% Brassica napus var. Zephyr rapeseed oil). Groups of 30 rats, housed 2 per cage, from each of three different strains of rats and groups of 10 rats, housed 2 per cage, from one strain of rats (Hooded) were fed semisynthetic diets containing the test oils for 16 weeks on an ad libitum basis. Rats of the Hooded strain consumed considerably less feed and grew at a significantly (P < 0.01) slower rate than did rats of the Sprague–Dawley C strain, which in turn ate less and grew significantly (P < 0.01) slower than rats of the other three strains. No marked differences were observed in the fatty acid composition of total cardiac lipids among strains. Rats from all strains except Hooded fed the diet containing 20% Zephyr RSO had a significantly (P < 0.001) higher incidence of myocardial lesions than rats fed the 20% corn oil diet which in turn had a significantly (P < 0.001) higher incidence than rats fed 5% corn oil. Similarly, significantly (P < 0.05) more Sprague–Dawley C rats had myocardial lesions than Sprague–Dawley A rats regardless of diet. None of the Hooded rats fed the diet containing 20% Zephyr RSO developed myocardial lesions whereas all other strains fed this diet developed a high incidence of myocardial lesions.

Myocardial lesions in rats fed rapeseed oil. II. Effects of castration

1977 ◽  
Vol 55 (2) ◽  
pp. 265-271 ◽  
Author(s):  
H. W. Hulan ◽  
J. K. G. Kramer ◽  
A. H. Corner ◽  
B. Thompson
Keyword(s):  
Rapeseed Oil ◽  
Corn Oil ◽  
Sprague Dawley ◽  
Semisynthetic Diet ◽  
Sprague Dawley Rats ◽  
Body Weights ◽  
Two Factors ◽  
The Mean ◽  
Heart Lesions ◽  
Myocardial Lesions

The effects of castration on the incidence of myocardial lesions in rats were investigated in an experiment which included two factors: sex (entire males, castrated males, entire females and castrated (ovariohysterectomized) females) and diets (5% corn oil, 20% corn oil, and 20% Brassica napus var. Zephyr rapeseed oil). For 16 weeks, each of the 12 groups of 30 Sprague–Dawley rats, housed 2 per cage, were fed ad libitum the test oils incorporated in a semisynthetic diet. At each weighing, the mean body weights for each diet were highest in entire males followed by castrated males, castrated females, and entire females with all differences significant (P < 0.05). The results indicated that castration did not influence cardiac fatty acid composition. The incidence of myocardial lesions in entire and castrated females and in castrated males was similar while significantly more entire males developed lesions (P < 0.001). Rats fed a diet containing 20% Zephyr rapeseed oil showed a significantly (P < 0.001) higher incidence of heart lesions than did rats fed diets containing 5% or 20% corn oil. Similarly, significantly (P < 0.05) more rats fed the 20% corn oil diet had lesions than rats fed the 5% corn oil diet. The involvement of androgens in the formation of myocardial lesions is suggested, since castration significantly lowered the incidence in males but not in females.

A COMPARISON OF THE UTILIZATION OF RAPESEED OIL AND CORN OIL BY THE RAT

1959 ◽  
Vol 37 (5) ◽  
pp. 613-621 ◽  
Author(s):  
Joyce L. Beare ◽  
T. K. Murray ◽  
H. C. Grice ◽  
J. A. Campbell
Keyword(s):  
Body Weight ◽  
Vitamin A ◽  
Rapeseed Oil ◽  
Wistar Rats ◽  
Corn Oil ◽  
Weekly Interval ◽  
Organ Weights ◽  
Weight Gains ◽  
Ad Libitum ◽  
Liver Storage

The effects of Golden rapeseed oil and corn oil on weekly weight gains, food consumptions, liver storage of vitamin A, plasma and adrenal cholesterol concentrations, organ weights, and testes histology were determined in Wistar rats for 5 weeks after weaning. At each weekly interval, animals fed rapeseed oil showed lesser weight gains and food consumptions, but, when body weight gains were adjusted for food consumptions by covariance analyses, differences largely disappeared. Liver storage of vitamin A was similar with both oils. Testes of animals fed rapeseed oil exhibited no alteration in cellular characteristics, but a reduction in tubular size. When fed to older rats, rapeseed oil again produced smaller weight gains which were accounted for at 4 weeks' time by a depressed appetite.Similar weight gains were obtained with corn oil and rapeseed oil when the oils were paired fed and when adjustments for food consumption were made by covariance analyses of weight gains of animals receiving the oils ad libitum. With corn oil supplied on a restricted basis the testicular tubules were smaller than those obtained with unrestricted feeding of corn oil. The absorption of corn oil and rapeseed oil fed ad libitum was 95 and 92% respectively. It was concluded that the two oils were not very differently utilized.

Electrocardiograms of male rats fed rapeseed oil

1977 ◽  
Vol 55 (5) ◽  
pp. 1116-1121 ◽  
Author(s):  
W. G. Hunsaker ◽  
H. W. Hulan ◽  
J. K. G. Kramer ◽  
A. H. Corner
Keyword(s):  
Rapeseed Oil ◽  
Corn Oil ◽  
Frontal Plane ◽  
P Wave ◽  
Male Rats ◽  
Qrs Complex ◽  
Sprague Dawley ◽  
Cardiac Rate ◽  
Sprague Dawley Rats ◽  
Wave Forms

Frontal plane electrocardiograms (standard limb leads) were recorded on male Sprague–Dawley rats fed for 14 weeks on semisynthetic diets containing 20% (by weight) of Brassica napus cv. Tower or B. campestris cv. Span rapeseed oil or fractions isolated from Span rapeseed oil. Control diets were rat Chow or semisynthetic diets containing 20% (by weight) of either safflower oil or corn oil. The amplitude of the P, Q, R, S, and T waves, the duration of the P wave, QRS complex, and P–R interval, and the cardiac rate were measured in the electrocardiograms and differences between groups compared statistically. While there were statistically significant differences in the amplitude of some of the wave forms, there were no consistent differences which could be attributed to the feeding of rapeseed oil or its fractions. The duration of the P wave and the QRS complex were significantly longer in some of the control groups than those in most of the treated groups. There was no correlation between the presence of a Q wave and the incidence of myocardial lesions in any group. Cardiac rate was essentially the same in all groups.

scholarly journals Ventilatory phenotypes among four strains of adult rats

2002 ◽  
Vol 93 (3) ◽  
pp. 974-983 ◽  
Author(s):  
Matthew R. Hodges ◽  
Hubert V. Forster ◽  
Paula E. Papanek ◽  
Melinda R. Dwinell ◽  
Genevieve E. Hogan
Keyword(s):  
Ventilatory Response ◽  
Strain Difference ◽  
Strain Differences ◽  
Inbred Strains ◽  
The Other ◽  
Brown Norway ◽  
Control Mechanisms ◽  
Sprague Dawley ◽  
Adult Rats ◽  
Different Strains

Our purpose in this study was to identify different ventilatory phenotypes among four different strains of rats. We examined 114 rats from three in-house, inbred strains and one outbred strain: Brown Norway (BN; n = 26), Dahl salt-sensitive ( n = 24), Fawn-hooded Hypertensive (FHH: n = 27), and outbred Sprague-Dawley rats (SD; n = 37). We measured eupneic (room air) breathing and the ventilatory responses to hypoxia (12% O2-88% N2), hypercapnia (7% CO2), and two levels of submaximal exercise. Primary strain differences were between BN and the other strains. BN rats had a relatively attenuated ventilatory response to CO2 ( P < 0.001), an accentuated ventilatory response to exercise ( P < 0.05), and an accentuated ventilatory roll-off during hypoxia ( P < 0.05). Ventilation during hypoxia was lower than other strains, but hyperventilation during hypoxia was equal to the other strains ( P > 0.05), indicating that the metabolic rate during hypoxia decreased more in BN rats than in other strains. Another strain difference was in the frequency and timing components of augmented breaths, where FHH rats frequently differed from the other strains, and the BN rats had the longest expiratory time of the augmented breaths (probably secondary to the blunted CO2 sensitivity). These strain differences not only provide insight into physiological mechanisms but also indicate traits (such as CO2 sensitivity) that are genetically regulated. Finally, the data establish a foundation for physiological genomic studies aimed at elucidating the genetics of these ventilatory control mechanisms.

THE INFLUENCE OF DIETARY FAT ON THE FATTY ACID COMPOSITION OF LIVER, CARCASS, AND MILK OF RATS

1961 ◽  
Vol 39 (12) ◽  
pp. 1855-1863 ◽  
Author(s):  
Joyce L. Beare
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Liquid Chromatography ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Dietary Fat ◽  
Rapeseed Oil ◽  
Corn Oil ◽  
Gas Liquid Chromatography ◽  
Long Chain

Fatty acids of liver, carcass, and milk of rats fed corn oil, rapeseed oil, partially hydrogenated herring oil, or margarine were examined by gas–liquid chromatography. Appreciable quantities of linoleic acid were maintained in the tissues and milk, even when the hydrogenated herring oil with a low level of linoleic acid was fed. The proportion of C20and C22acids deposited or secreted was related to that of the diet, and was highest with rapeseed oil. In the livers of rats fed each diet, long-chain, polyunsaturated acids were observed. The fatty acids of milk more closely reflected the dietary pattern than did those of the tissues.

THE EFFECT OF GLUCAGON ON PREGNANCY IN THE RAT

1965 ◽  
Vol 43 (4) ◽  
pp. 473-490 ◽  
Author(s):  
S. A. Holloway ◽  
J. A. F. Stevenson
Keyword(s):  
Late Pregnancy ◽  
Fetal Weight ◽  
Stillbirth Rate ◽  
Protein Catabolism ◽  
Sprague Dawley ◽  
Fetal Physiology ◽  
Sprague Dawley Rats ◽  
High Incidence ◽  
Ad Libitum ◽  
Dose Levels

Pregnant Sprague–Dawley rats were given glucagon during the first, second, or third week of gestation. The effects on maternal and fetal physiology were studied and were compared with those of adrenaline. At all dose levels (0.5–2.0 mg/kg twice daily), glucagon significantly reduced maternal and fetal weights when given from day 13 to day 20 of gestation. Placenta weights were reduced, and there was a high incidence of premature and postmature deliveries, the latter associated with a high stillbirth rate. Glucagon (1.0 mg/kg twice daily) had little or no effect on maternal nitrogen balance or on fetal weight when given from day 0 to day 7 or from day 7 to day 13 of gestation. When administered from day 13 to day 20 there was a significant reduction in fetal weight compared with that of the controls, pair fed or fed ad libitum. Less nitrogen and probably more water were retained than in the controls. No significant increase in resting oxygen consumption was detected after injection of glucagon. The results indicate that the effect of excess glucagon on the fetus is mediated partly by a reduction in maternal food intake and partly by increased maternal protein catabolism. It seems unlikely to be due to an increase in resting expenditure of maternal energy or to the liberation of endogenous adrenaline. The increase in glucagon sensitivity in late pregnancy may be related to an increase in insulin resistance, known to occur at this time.

RESPONSES OF TWO STRAINS OF RATS TO RAPESEED OIL AND CORN OIL

1960 ◽  
Vol 38 (3) ◽  
pp. 187-192 ◽  
Author(s):  
Joyce L. Beare ◽  
T. K. Murray ◽  
J. A. Campbell
Keyword(s):  
Vitamin A ◽  
Rapeseed Oil ◽  
Wistar Rats ◽  
Corn Oil ◽  
Strain Differences ◽  
Basal Diet ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Significant Difference ◽  
Dietary Oil

Wistar and Sprague–Dawley rats were compared in their response to 20% rapeseed oil or corn oil in a basal diet of ground fox cubes. Apparent coefficients of digestibility were significantly lower for rapeseed oil than for corn oil in the Sprague–Dawley, but not in the Wistar rats. After 6 weeks the adrenals of Sprague–Dawley rats were larger in the animals fed rapeseed oil than in those fed corn oil, while the adrenals of Wistar rats were not influenced by the dietary oil. These strain differences explain some discrepancies appearing in the literature concerning the effects of rapeseed oil in the rat.In another experiment, Wistar and Sprague–Dawley rats deprived of vitamin A for 18 days were fed a purified basal diet with 20% rapeseed oil or corn oil and dosed with 75 or 150 I.U. of vitamin A per day. After 14 days there was no significant effect of the strain of rat or the type of dietary oil on the liver storage of vitamin A. The rate of depletion of vitamin A from the liver following a single dose of 1200 I.U. of vitamin A was also studied and indicated no significant difference attributable to the dietary oils.

A COMPARISON OF THE UTILIZATION OF RAPESEED OIL AND CORN OIL BY THE RAT

1959 ◽  
Vol 37 (1) ◽  
pp. 613-621 ◽  
Author(s):  
Joyce L. Beare ◽  
T. K. Murray ◽  
H. C. Grice ◽  
J. A. Campbell
Keyword(s):  
Body Weight ◽  
Vitamin A ◽  
Rapeseed Oil ◽  
Wistar Rats ◽  
Corn Oil ◽  
Weekly Interval ◽  
Organ Weights ◽  
Weight Gains ◽  
Ad Libitum ◽  
Liver Storage

The effects of Golden rapeseed oil and corn oil on weekly weight gains, food consumptions, liver storage of vitamin A, plasma and adrenal cholesterol concentrations, organ weights, and testes histology were determined in Wistar rats for 5 weeks after weaning. At each weekly interval, animals fed rapeseed oil showed lesser weight gains and food consumptions, but, when body weight gains were adjusted for food consumptions by covariance analyses, differences largely disappeared. Liver storage of vitamin A was similar with both oils. Testes of animals fed rapeseed oil exhibited no alteration in cellular characteristics, but a reduction in tubular size. When fed to older rats, rapeseed oil again produced smaller weight gains which were accounted for at 4 weeks' time by a depressed appetite.Similar weight gains were obtained with corn oil and rapeseed oil when the oils were paired fed and when adjustments for food consumption were made by covariance analyses of weight gains of animals receiving the oils ad libitum. With corn oil supplied on a restricted basis the testicular tubules were smaller than those obtained with unrestricted feeding of corn oil. The absorption of corn oil and rapeseed oil fed ad libitum was 95 and 92% respectively. It was concluded that the two oils were not very differently utilized.

RESPONSES OF TWO STRAINS OF RATS TO RAPESEED OIL AND CORN OIL

1960 ◽  
Vol 38 (1) ◽  
pp. 187-192 ◽  
Author(s):  
Joyce L. Beare ◽  
T. K. Murray ◽  
J. A. Campbell
Keyword(s):  
Vitamin A ◽  
Rapeseed Oil ◽  
Wistar Rats ◽  
Corn Oil ◽  
Strain Differences ◽  
Basal Diet ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Significant Difference ◽  
Dietary Oil

Wistar and Sprague–Dawley rats were compared in their response to 20% rapeseed oil or corn oil in a basal diet of ground fox cubes. Apparent coefficients of digestibility were significantly lower for rapeseed oil than for corn oil in the Sprague–Dawley, but not in the Wistar rats. After 6 weeks the adrenals of Sprague–Dawley rats were larger in the animals fed rapeseed oil than in those fed corn oil, while the adrenals of Wistar rats were not influenced by the dietary oil. These strain differences explain some discrepancies appearing in the literature concerning the effects of rapeseed oil in the rat.In another experiment, Wistar and Sprague–Dawley rats deprived of vitamin A for 18 days were fed a purified basal diet with 20% rapeseed oil or corn oil and dosed with 75 or 150 I.U. of vitamin A per day. After 14 days there was no significant effect of the strain of rat or the type of dietary oil on the liver storage of vitamin A. The rate of depletion of vitamin A from the liver following a single dose of 1200 I.U. of vitamin A was also studied and indicated no significant difference attributable to the dietary oils.

The development of dermal lesions and alopecia in male rats fed rapeseed oil

1976 ◽  
Vol 54 (1) ◽  
pp. 1-6 ◽  
Author(s):  
H. W. Hulan ◽  
W. G. Hunsaker ◽  
J. K. G. Kramer ◽  
S. Mahadevan
Keyword(s):  
Fatty Acid ◽  
Rapeseed Oil ◽  
Corn Oil ◽  
Fatty Acid Analysis ◽  
Male Rats ◽  
Sprague Dawley ◽  
Semisynthetic Diet ◽  
Prostaglandin Biosynthesis ◽  
Sprague Dawley Rats ◽  
Dermal Lesions

For 8 weeks 10 male weanling Sprague–Dawley rats were fed a semisynthetic diet containing by weight either 20% corn oil or rapeseed oils containing different amounts of erucic acid (Brassica napus var. Zephyr, 0.6%; B. napus var. Oro, 1.8%; B. campestris var. Span, 4.8%; or B. campestris var. Echo and Arlo, i.e., regular rapeseed oil, 23.6%). At 4–5 weeks after the experiment began, rats receiving the diets containing rapeseed oil showed evidence of alopecia and developed scaly, hemorrhagic, and necrotic tails, as well as scaliness of the feet, similar to the lesions described in essential fatty acid (EFA) deficiency. This condition became most severe between 5 and 8 weeks and had disappeared by 14 weeks. Fatty acid analysis of the diets and tissues of the animals did not reveal any evidence of EFA deficiency. It is suggested that these symptoms observed might be related to a possible inhibition of prostaglandin biosynthesis in rats fed rapeseed oils.

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