In this five-week feeding study male New Zealand rabbits were fed diets containing cyclopropene fatty acids (CPFA), diets containing cholesterol, and diets with both CPFA and cholesterol added to test the effect of CPFA on cholesterol metabolism and atherosclerosis induction. When CPFA-fed animals were compared with control animals, they tended to have higher plasma cholesterol levels, higher liver cholesterol levels and a high incidence of aortic atherosclerosis. Control animals had no atherosclerosis. A similar pattern was seen when animals fed cholesterol were compared with those fed both cholesterol and CPFA. Mean triglyceride levels were higher in CPFA-fed rabbits than in controls. A wide range of sensitivity to the CPFA was observed. Some animals had plasma cholesterol levels eight to ten times normal after three weeks of feeding; others showed only slight changes after five weeks. Histological examination of liver cells from CPFA-fed animals showed evidence of alteration in cellular morphology and, in some cases, extensive damage. In some liver cells of CPFA-fed rabbits, subcellular organelles appear to be aligned in fiber-like structures. The most extreme signs of toxicity were noted in livers of rabbits fed CPFA and cholesterol. After five weeks on experimental diets, adipose tissue of the rabbits contained approximately 2% CPFA. Ratios of 16:0 to 16:1 and 18:0 to 18:1 fatty acids increased in liver lipid and erythrocyte ghost lipid after CPFA feeding. Over the five-week study there were no differences in rate of weight gain or in feed conversion ratios in CPFA-fed animals. / Graduation date: 1974

Cyclopropene fatty acids (CPFA) found in cottonseed oil (CT) have been shown to reduce production of progesterone, a precursor of estrogen. Estrogenic hormones have been implicated in enhancing growth of mammary tumors. In this study, the effect of dietary cottonseed oil on estrogen production by mature female mice was determined by measuring urinary estrogen using High Performance Liquid Chromatography.At four months of age, five groups of three Strain A/ST female mice were placed on 20% fat diets containing 0, 2.5, 5.0, 10, and 20% cottonseed oil. The remainder of the fat in the experimental diets was corn oil sufficient to provide the balance of the 20% fat content in conjunction with other nutrients of equal percentages in all diets. At five day intervals mice were housed in metabolic cages and twenty-four hour urine samples were collected. Urine was purified on C18 columns and eluted with 1% phosphoric acid: acetonitrile: methanol: (54:35:11). Estrogen was quantified by High Performance Liquid Chromatography using a 250 X 5mm C18 column, hydrocortisone as an internal standard, and variable wavelength recorder set at 242 nm. The level of urinary estrogens after day 35 of the study was lower in all diets containing cottonseed oil. This is in agreement with several authors who have reported instances of physiological abnormalities in mammals which were fed increasing but low levels of dietary cyclopropenes. Since elevated estrogen levels have been identified as a risk for breast cancer, this study examines the relationship between dietary cyclopropenes and estrogen hormone production in strain A/St mice. / Department of Biology

Dietary fatty acids are considered promoters of murine and human mammary tumors. The mechanism responsible is not known. Mammary adenocarcinomas in mice originate from preneoplastic cells (hyperplastic alveolar nodules (HAN)) which are derived from normal mammary epithelial cells. Diets rich in linoleic acid (18:2) have been associated with increased incidence of HAN and promotion of tumor growth. Diets rich in stearic acid (18:0) have been associated with decreased incidence of HAN and increased latency period for mammary tumor formation in mice.The effects of dietary 18:0 and 18:2 stages of murine mammary tumorigenesis were examined. The purpose of this study was to determine the effects of these dietary fatty acids on HAN production, mammary gland development, and fatty acid composition of mammary epithelial cells and adipocytes.Spontaneous mammary tumor producing strain A/ST mice were fed a high fat (15%) or low fat (5%) diet. High fat stock (ST) diet containing 1.5% 18:2 or a low fat corn oil (CO) diet containing 3% 18:2 were fed. Animals were sacrificed at 6 or 10 months of age. HAN, ductile and alveolar development were histologically determined in the left inguinal mammary gland. The contralateral gland was on the early diets rich in 18:2 (SF) or 18:0 (SA) were fed. A low*fat enzymatically dissociated and fatty acid compositions of adipocyte and epithelial cells were determined by GLC. Fatty acid profiles were examined for correlation to histologic findings.SA-fed mice had fewer HAN and less well developed mammary alveoli than the other dietary groups which exhibited moderate (ST) or high (CO, SF) HAN incidence. SF-fed mice had the earliest onset of any dietary group. CO-fed mice had later onset of HAN as compared to SF-fed mice but the HAN incidence was similarly high in both groups at 10 months of age.SA-fed mice were protected from development of expected numbers of HAN as compared to ST-fed mice. The reduction in HAN risk in this group was associated with reduced mammary alveolar development. Groups with high risk of HAN (SF and CO) exhibited increased amounts of 18:2 in their mammary epithelial cells and adipocytes. / Department of Biology

Three studies were designed to evaluate the promoting effect of cyclopropenoid fatty acids (CPFA) on avian myeloblastosis virus (AMV) infection in White Leghorn chickens. In the first study effects on growth parameters, blood serum and erythrocyte lipid composition of White Leghorn chickens were investigated at 100 ppm and 300 ppm dietary CPFA. In comparison to controls, chicks fed dietary CPFA had reduced body weights and food intake. At both levels, CPFA increased the saturated fatty acids and decreased monoenes in blood serum and erythrocyte triacylglycerols and phospholipids. In a second study, the effects of high dietary (300 ppm) CPFA on AMV infectivity were investigated. Chicks were inoculated with 0.1 ml AMV at 7 days of age. A diet containing CPFA was fed before and after inoculation. CPFA/AMV treated chicks showed a marked reduction in body weight gain and food consumption in comparison to controls. CPFA appeared to promote AMV infection along with unexpected violent hemorrhagic manifestations. These hemorrhagic manifestations appeared to cause death before AMV induced myeloblast proliferation in the circulating blood. In comparison to controls, CPFA altered the phospholipid composition of isolated myeloblasts and the cholesterol/phospholipid ratio of isolated myelobasts, myeloblast plasma membrane, and virus particles. Analysis of the acyl group composition of choline and ethanolamine phospholipids from CPFA treated myeloblasts and myeloblast plasma membrane revealed an increase in saturated fatty acid and a decrease in monoenes. In both, CPFA appeared to affect ethanolamine more than choline phospholipids. In contrast, the alterations observed in CPFA treated virus particle choline and ethanolamine fatty acyl chains were reversed from those found in the myeloblast and myeloblast plasma membrane. In addition, ATPase specific activity was altered in relation to the CPFA induced lipid changes in the myeloblast plasma membrane and virus particle. It was shown that as saturation increased enzyme activity increased. As a third investigation, the effects of low dietary (75 ppm and 150 ppm) CPFA on AMV infection was conducted in an attempt to eliminate the hemorrhagic manifestations. A difference that was observed between this investigation and the 300 ppm CPFA/AMV study was less severe hemorrhagic responses. Histological examination of CPFA treated liver and spleen by light microscopy revealed heavy infiltration of mitotic myeloblasts into each tissue. Analysis of the number of virus particle/ml by reverse transcriptase revealed 300 ppm dietary CPFA stimulated the synthesis and release of virus particles. This was in contrast with 150 ppm dietary CPFA which retarded the synthesis and release of virus particles. / Graduation date: 1982

The DNA repair capabilities of rainbow trout (Salmo gairdneri) were studied vising the method of autoradiography. Trout were fed a semi-purified control diet containing 0 ppm, 50 ppm, or 300 ppm cyclopropenoid fatty acids (CPFA) for 6-9 weeks. Liver slices were prepared and exposed in vitro to a control treatment, ultraviolet irradiation (UV), ethidium bromide (EB), UV/EB in succession, or aflatoxin B₁. The degree of DNA repair was analyzed in terms of net grains per cell. Except following the EB treatment, fish on the control diet revealed an absence of ongoing DNA repair. Trout fed 50 ppm CPFA exhibited a consistently low level of repair over time following the in vitro control treatment. Fish fed 300 ppm CPFA revealed a relatively higher degree of ³H-Me-thymidine incorporation indicative of induced DNA repair following the in vitro control treatment, and the degree of repair increased with time on the diet. UV-irradiation caused a marked increase in the degree of induced DNA repair in 300 ppm CPFA fish at 6 and 7.5 weeks, and in 50 ppm CPFA fish at 7.5 weeks. Follcwing UV-irradiation, liver slices were exposed to EB, a DNA intercalating agent used to inhibit normal DNA replication. However, in contrast to the desired effect, EB caused a marked decrease in the degree of repair synthesis observed in 300 ppm CPFA fish at 6 and 7.5 weeks. Indicative of intercalation, the in vitro EB treatment caused a moderate degree of ³H-Me-thymidine incorporation in fish fed the control diet. Repair was also induced in 300 ppm CPFA fish following exposure to EB at 6 and 7.5 weeks. Aflatoxin B₁ induced DNA repair to various degrees in fish on all diets at 7.5 and 9 weeks. In comparison to the in vitro control treatment, it was observed that the degree of induced DNA repair was decreased significantly - "completely" following the UV, UV/EB, and EB treatments - in fish fed the 300 ppm CPFA diet for 9 weeks. In view of the low level of DNA repair observed in rainbow trout using autoradiography, the repair capabilities were studied using a more sensitive assay, bromodeoxyuridine (BrdU) photolysis. Isolated hepatocytes were prepared from fish fed the various diets and exposed in vitro to a control treatment, UV-irradiation, or 4-nitroquinoline-N-oxide. The obtained results were nonconclusive indicating technical improvements on the assay need to be made. / Graduation date: 1988

Three experiments were conducted to study the influence of dietary fatty acids on the production performance and immune response of chickens. In experiment I, forty day-old broiler chicks were fed diets containing 5% of either animal fat + conjugated linoleic acid (CLA) (Diet I), sunflower oil (Diet II), flax oil (Diet III) or fish oil (Diet IV). No significant differences (P>0.05) were observed between the live weight of birds. The liver tissue total fat content was lower (P<0.05) in treatment I and II. The fatty acid composition of breast and thigh muscle, liver, heart, pericardial fat, plasma, splenocytes and gut associated lymphoid tissue differed (P<0.05) between treatments. The thiobarbituric acid reactive substances (TBARS) of breast and thigh muscle, liver and heart tissue were lower (P<0.05) in Diet I fed birds. Serum antibody activity was decreased (P<0.05) in Diet II fed birds. In experiment II, 120 day-old broiler chicks were fed diets containing 3.5% of either animal fat + conjugated linoleic acid (CLA) (Diet I), sunflower oil (Diet II), linseed oil (Diet III) or fish oil (Diet IV). Body weight gain was higher (P<0.05) in Diets III and IV compared to Diets I and II fed birds. Feed intake was increased (P<0.05) in Diet IV fed birds. Birds fed Diets III and IV had higher (P<0.05) n-3 fatty acids in all tissues studied. A preferential incorporation of CLA was observed in spleen mononuclear cells. TBARS were higher (P<0.05) in the breast and thigh muscle of Diet IV fed birds. Serum anti-BSA antibody content was higher (P<0.05) in birds fed Diets III and IV. Delayed type hypersensitivity (DTH) response was increased (P<0.05) in Diets IV and III fed birds. Lymphocyte and spleen mononuclear cell CD4⁺, CD8⁺ and IgM⁺ cell population did not differ (P>0.05) among treatments. In experiment III, 120 layer birds were fed diets containing 3% of CLA+animal fat (Diet I), sunflower oil (Diet II), canola+flax oil (Diet III) or fish oil (Diet IV). Egg production, feed consumption and feed efficiency did not differ (P>0.05) among treatments. Birds fed Diets III and IV had higher content of n-3 fatty acids in eggs. Eggs from hens fed Diet I incorporated higher (P<0.05) CLA and saturated fatty acids with a concomitant reduction in (P<0.05) monounsaturated fatty acid content. A preferential incorporation of CLA was observed in eggs over other tissues. TBARS were higher (P<0.05) in breast and thigh muscle of Diet IV fed birds. Egg TBARS content did not differ (P>0.05) among treatments. Serum and yolk anti-BSA antibody contents were higher (P<0.05) in birds fed Diets III and IV. DTH response was increased (P<0.05) in Diets IV and III fed birds. Lymphocyte and spleen mononuclear cell CD4⁺, CD8⁺ and IgM⁺ cell population did not differ (P>0.05) among treatments. Feeding n-3 fatty acids increased antibody mediated immune response while n-6 fatty acids and CLA increased cell mediated immune response. / Graduation date: 2003

Graduation date: 1995

Inflammation is the body's response to injury and is characterized by pain, swelling, redness, and heat. Eicosanoids are lipid mediators of inflammation. Leukotrienes (LT) are 20-carbon eicosanoids produced from arachidonic acid (AA), an n-6 fatty acid (FA), and eicosapentaenoic acid (EPA), an n-3 FA. LT produced from AA are proinflammatory (LTB₄) and those produced from EPA (LTB₅) are less inflammatory. Two experiments were conducted. The objective of the first experiment was to optimize the assay conditions for LT production by platelets from chickens, and neutrophils from horses and dogs. Optimal production of LT from equine and canine neutrophils and chicken platelets was characterized in terms of incubation time (2.5, 5, 10, 15 or 20 minutes), temperature (25 or 37°C), and calcium ionophore A23187 concentration (0.1, 1, 10 or 20 μM). In all species, incubation at 37°C resulted in optimal LTB₄ production compared to 25°C (p≤0.05). Production of LTB₄ was maximum when neutrophils were stimulated with 20 μM calcium ionophore A23187 in all species (p≤0.05). Incubation times greater than 2.5 minutes did not further increase LTB₄ production in chickens and horses; in dogs, incubation for 2.5 and 10 minutes resulted in the highest concentrations of LTB₄ (p≤0.05). These results indicate that platelets from chickens, and neutrophils from horses and dogs, are capable of producing LTB₄; optimum conditions for LTB₄ production are similar in all three species. In the second study, the effect of feeding diets that differed in n-6 and n-3 FA ratios to breeder hens was investigated with regard to changes in composition of immune tissue, alteration of delayed-type-hypersensitivity (DTH) response, and LT production by platelets. Chicks hatched to hens fed these diets were also studied with regard to fatty acid composition of immune tissues and LT production by platelets at various stages of growth (7, 14, 21 days). A total of 72 breeder hens were randomly divided into three groups (n=24) and fed diets supplemented with either 3.0% (by weight) sunflower oil (SF0; rich in n-6 FA; Diet I), a mixture of 1.5% SF0 and 1.5% fish oil (Diet II), or 3.0% fish oil (FO; rich in n-3 FA; Diet III). Production of LTB₄ and LTB₅ by platelets stimulated with calcium ionophore A23187 were assessed by RP-HPLC. The hens fed Diet I synthesized 43.9 ± 2.5 ng of LTB₄ per 5x10⁶ cells compared to 13.3 ± 0.9 ng of LTB₄ from hens fed Diet II (p≤0.05). However, no LTB₄ was produced by hens fed Diet III. Production of LTB₅ by platelets of hens fed Diet III was 36.7 ± 4.9 ng compared to 47.4 ± 5.7 ng of LTB₅ from hens fed Diet II. No LTB₅ was produced by hens fed Diet I. The DTH reaction was smaller at 48 hrs post injection of bovine serum albumin in hens fed the 3% FO Diet III (p≤0.05). Fatty acid composition spleen and platelets in hens reflected the fatty acid composition of diets consumed by them (p≤0.05). Hatched chicks from hens fed Diet I produced significantly less LTB₄ at 14 days (p≤0.05) compared to 7- and 21-day-old chicks, which were not different from each other. Chicks from hens fed Diet II produced more LTB₄ at 21 days (p≤0.05) compared chicks from hens fed Diet III produced more LTB₄ at 7 and 21 days (p≤0.05) compared to 14-day-old chicks. There were no significant differences in LTB₅ production from chicks hatched to hens fed Diet III at 7 and 14 days of growth. By 21 days of growth, chicks hatched to hens fed Diet III showed decreased production of LTB₅ compared to 7- and 14-day-old chicks. The spleen and bursa tissue fatty acid composition in chicks at 7 and 14 days of age were similar to the maternal diet fatty acid composition, however, there were no significant differences in platelet fatty acid composition between the groups at different stages of growth. These results indicate that the type of fat in diets fed to breeder hens may alter the inflammatory response in hatched chicks, which could lead to less mortality and increased production performance in poultry. / Graduation date: 2005

We have previously shown that diets enriched with (n-3) fatty acids reduced the delayed-type hypersensitivity (DTH) skin reaction to keyhole limpet haemocyanin (KLH) in geriatric-Beagles. Although the amount of ��-tocopheryl acetate in diets of the previous study exceeded requirements, plasma ��-tocopherol concentration was significantly lower in dogs fed the high (n-3) fatty acid diets. There are several reasons that could explain the decreased DTH response. Some of these include decreased cytokine production, specifically, interleukin (IL) IL-1��, tumor necrosis factor (TNF) and IL-6 by mononuclear cells. Furthermore, the reduced DTH response could be attributed to increased levels of lipid peroxides or changes in plasma ��-tocopherol levels. In this study we examined the effects of feeding 32 healthy, female, geriatric-Beagles diets containing (n-6) to (n-3) fatty acid ratios of 37:1 and 1.7:1, while varying the content of ��-tocopheryl acetate, [high (447 ug/g), med (101 ug/g) and low (17 ug/g)] for 82 days on the DTH reaction. Consumption of the 1.7:1 fatty acid diets significantly increased the total content of (n-3) fatty acids in plasma compared to the 37:1 fatty acid diets (17.00 and 2.02 wt %, respectively). There was a significant interaction between the (n-6) and (n-3) fatty acid ratio and the concentration of ��-tocopheryl acetate in the diet on the plasma concentration of ��-tocoopherol. The concentration of ��-tocopheryl acetate in plasma of dogs fed the 1.7:1 fatty acid diets was 17.3, 25.4, and 35.4 ug/ml, respectively, for the low, med and high ��-tocopheryl acetate containing diets, and in dogs fed the 37:1 fatty acids diets was 20.8, 34.9, 52.4 ug/ml, respectively. Consumption of the 1.7:1 fatty acid diets with either low or high ��-tocopheryl acetate showed no differences in DTH response from each other or from dogs consuming the 37.1:1 fatty acid diets. When the dietary ��-tocopheryl acetate concentration was moderate, a significant suppression of the DTH response occurred at 48, 72, and 96 hr in dogs consuming the 1.7:1 fatty acid diet. These data suggest that an interaction exits between dietary (n-3) fatty acid content and ��-tocopheryl acetate on the immune response as measured by the DTH test. / Graduation date: 2000

The effect of fatty acids on energy metabolism has been shown to be dependent on their acyl structure. In humans, following short term feeding, medium chain triglycerides (MCT) have been shown to increase the thermic effect of food and fat oxidation as compared to long chain triglycerides (LCT). Short term results in animals have been comparable. In longer term, animal studies, MCT vs. LCT have resulted in less weight gain during overfeeding or refeeding after weight loss. However, observations of the longer term effects of MCT in humans beyond 7 days are sparse and inconclusive. Hence, the objective of the thesis was to examine the effects of MCT vs. LCT on total energy expenditure, its components basal metabolic rate and thermic effect of food, and on substrate oxidation, including both exogenous and endogenous fat oxidation for a period of one week, following one week of prefeeding. Twelve healthy college aged women were fed eucaloric 14 days diets enriched with either MCT or LCT in a randomized cross over design, with a two week washout period. Doubly labelled water, respiratory gas exchange analysis, and 1-13C labelled myristic, palmitic, and stearic acids were used to measure total energy expenditure, components of energy expenditure, and endogenous long chain fatty acid oxidation, respectively. The presence of MCT in the diet significantly increased endogenous oxidation of labelled long chain fatty acids following 14 days of feeding, while the presence of LCT did not. Respiratory gas exchange analysis showed significantly increased basal metabolic rate on day 7 of MCT vs. LCT feeding, but this effect of diet was reduced to a trend by day 14. Dietary treatment did not result in significant differences in total energy expenditure during the second week of feeding. These results suggest that, after two weeks of feeding, MCT continue to affect energy metabolism through increased endogenous fat oxidation and a suggestion of heightened basal metabolic rate, but