Polyunsaturated fatty acids (PUFA) affect key cellular and physiological processes in the body ranging from cell signalling to inflammation. Compositional, dietary refinement and bioassay studies have shown strong associations between the PUFA composition of skeletal muscle with various contractile properties as well as the development of obesity and insulin resistance. The incorporation of PUFAs into rat soleus (slow-twitch oxidative), red gastrocnemius (fast-twitch oxidative), and white gastrocnemius (fast-twitch glycolytic) muscle were examined using stable isotope-labelled fatty acids. Two separate tracer studies were conducted. In the first study, four groups of rats were orally dosed with one of three isotopes of 18:2n-6; 13C18-18:2n-6 ethyl ester, 13C18- 18:2n-6 nonesterified fatty acid or 2H5-18:2n-6 ethyl ester and a control group received the vehicle only (olive oil). Animals were sacrificed 8 hours post dosing and soleus, red and white gastrocnemius muscles were collected for lipid analysis. In the second study, rats were orally administered a single dose of a mixture of 4 isotopes (13C18-18:2n-6, 2H5-18:3n-3, 13C16-16:0, and 2H2-18:1n-9) or vehicle only (olive oil) as a control. Groups of animals were sacrificed at 8, 24, and 48 h after dosing and four muscle types (heart, soleus, red and white gastrocnemius) were collected and analyzed for isotopic signal of these fatty acids and their corresponding desaturation and/or elongation products. Soleus accumulated significantly higher concentrations of labelled 18:2n-6, 18:3n-3 and most of n-6 fatty acids derived from 18:2n-6 followed by red gastrocnemius and white gastrocnemius. Heart muscle accumulated 20:5n-3 and 22:6n-3 increasingly over time while skeletal muscle accumulation was variable across muscle types. Labelled 20:5n-3 was detected in red and white gastrocnemius at 8 and 24 h with levels declining by 48 h while no 20:5n-3 was detected in soleus at anytime. Labelled 22:6n-3 was not detected in white gastrocnemius, but 22:6n-3 appeared to be increasing in red gastrocnemius over time. Soleus demonstrated a large accumulation of 22:6n-3 at 8 h with no detectable levels at 48 h. In conclusion we were able to demonstrate that the distribution and metabolism of various PUFAs differ in muscle types with distinct fibre type composition.

Polyunsaturated fatty acids (PUFA) affect key cellular and physiological processes in the body ranging from cell signalling to inflammation. Compositional, dietary refinement and bioassay studies have shown strong associations between the PUFA composition of skeletal muscle with various contractile properties as well as the development of obesity and insulin resistance. The incorporation of PUFAs into rat soleus (slow-twitch oxidative), red gastrocnemius (fast-twitch oxidative), and white gastrocnemius (fast-twitch glycolytic) muscle were examined using stable isotope-labelled fatty acids. Two separate tracer studies were conducted. In the first study, four groups of rats were orally dosed with one of three isotopes of 18:2n-6; 13C18-18:2n-6 ethyl ester, 13C18- 18:2n-6 nonesterified fatty acid or 2H5-18:2n-6 ethyl ester and a control group received the vehicle only (olive oil). Animals were sacrificed 8 hours post dosing and soleus, red and white gastrocnemius muscles were collected for lipid analysis. In the second study, rats were orally administered a single dose of a mixture of 4 isotopes (13C18-18:2n-6, 2H5-18:3n-3, 13C16-16:0, and 2H2-18:1n-9) or vehicle only (olive oil) as a control. Groups of animals were sacrificed at 8, 24, and 48 h after dosing and four muscle types (heart, soleus, red and white gastrocnemius) were collected and analyzed for isotopic signal of these fatty acids and their corresponding desaturation and/or elongation products. Soleus accumulated significantly higher concentrations of labelled 18:2n-6, 18:3n-3 and most of n-6 fatty acids derived from 18:2n-6 followed by red gastrocnemius and white gastrocnemius. Heart muscle accumulated 20:5n-3 and 22:6n-3 increasingly over time while skeletal muscle accumulation was variable across muscle types. Labelled 20:5n-3 was detected in red and white gastrocnemius at 8 and 24 h with levels declining by 48 h while no 20:5n-3 was detected in soleus at anytime. Labelled 22:6n-3 was not detected in white gastrocnemius, but 22:6n-3 appeared to be increasing in red gastrocnemius over time. Soleus demonstrated a large accumulation of 22:6n-3 at 8 h with no detectable levels at 48 h. In conclusion we were able to demonstrate that the distribution and metabolism of various PUFAs differ in muscle types with distinct fibre type composition.

No description available.

We hypothesized that subcutaneous (s.c.) adipose tissue would differ in monounsaturated (MUFA) and saturated fatty acid (SFA) composition among different depots throughout a beef carcass. To test this, 50 carcasses from a variety of breed types and backgrounds were sampled. External fat samples were collected from eight different carcass locations: round, sirloin, loin, rib, chuck, brisket, plate and flank. Samples were used to provide information on slip points, fatty acid composition and MUFA:SFA ratios. Lipids were extracted from s.c. adipose tissue by a modified chloroform:methanol procedure, and fatty acid composition and slip points were measured. The brisket was significantly lower in palmitic (16:0) and stearic (18:0) acid than the other seven sampling sites (P = 0.001). The brisket demonstrated the highest values of MUFA (P = 0.001) with the exception of possessing the lowest value of transvaccenic (18:1t11) acid (P = 0.002). There were also significant differences in the amounts of PUFA among the eight sampling sites. The lowest values were from the brisket with a mean of 25.1. The flank had the highest slip point with a mean of 39.0 (P < or = 0.001). There was a high negative correlation shown between palmitoleic and stearic acid (R2 = 0.827). The brisket displayed the highest values for MUFA:SFA ratios (P = 0.001), whereas the flank was the lowest. Due to the significant differences amongst fat depots within bovine carcasses in their fatty acid composition we conclude that substantial differences exist across fat depots.

These studies were designed to evaluate the relationships that exist between residual feed intake, parity, rate of return to estrous cyclicity and nonesterified fatty acid (NEFA) concentrations, as well as changes in both body weight (BW) and body condition score (BCS) during the prepartum and postpartum time periods in Brahman females. Residual feed intake classification was evaluated for all females during the course of 70-d trials conducted prior to these experiments. Heifers (n = 30) and cows (n = 63) were evaluated for BW and BCS, as well as by collection of weekly blood samples beginning five weeks prior to calving. Blood serum samples were utilized to assay for NEFA concentrations by enzymatic colorimetry both pre- and postpartum. Multiparous females (n = 44) were sampled weekly for five weeks following parturition. Beginning 28d postpartum, weekly blood samples were collected and assayed for progesterone concentrations by radioimmunoassay to determine return to estrous cyclicity. Following calving, females were exposed to epididymectomized bulls fitted with chin-ball markers to aid in estrus detection. After detection, estrus females were evaluated for presence of a corpus luteum by trans-rectal ultrasonography. Prepartum, it was found that inefficient females had a greater BCS than efficient females (P < 0.05), significant BW changes occurred during the sampling period (P < 0.05) and moderate to low correlations existed between BW and BCS. Additionally, it was found that the interaction between RFI x parity had a significant affect upon NEFA concentrations, BW and BCS (P < 0.05). During the postpartum period it was found that efficient females were lower in both BW and BCS (P < 0.05), no change occurred over time in NEFA concentrations (P > 0.1) and a greater pregnancy rate was achieved in efficient females, as well as in females that returned to estrous cyclicity rapidly (< 90d) following calving.

A study was performed to investigate the effect of diets rich in polyunsaturated fatty acids and other related nutrients, in the effort to improve skin and hair coat conditions in canines. The study included 24 dogs fed a baseline diet (Ol’Roy®), with an acclimation period of 12 weeks (Phase I). Nine female beagles and 15 male hound mixed-bred dogs were used. For the next 12 weeks (Phase II) the dogs were randomly divided into three groups and fed one of three specially formulated complete and balanced diets. Differences among the three diets were as follows: Diet A contained lower but adequate amounts of dietary zinc and linoleic acid than Diet B. Diet C was similar to Diet B with respect to zinc but contained less linoleic acid and more alpha-linolenic acid. In the beginning, a preliminary study assessing skin lipids showed that hair is a suitable material to analyze. This study lead to the subsequent investigation, using plucked and shed hair samples obtained on weeks 3, 7, and 11 (Phase I) and again on weeks 1, 3, 7, and 11 (Phase II). One objective of this research was to investigate the dietary effects of the combination of linoleic acid in combination with zinc on canine sebum lipids during a 12 week diet phase. Another objective was to investigate if any correlation existed between the hair cycle anagen and telogen phase of the hair follicle and the lipid constituents present in the sebum during the 12 week acclimation phase and the 12 week feeding trial. Two hypotheses were tested. First, the lipid content of hair can be altered by fat and fatty acid composition of the diet. Second, the modification of dietary fat and polyunsaturated fatty acids lead to changes in hair lipids that may be related to improved skin and hair coat scores. Over the 12 week feeding period of Phase II, test results revealed statistically significant increases in both CE and CE/WD, and a prolonged growth of hair follicles in the anagen phase of diet B dogs, which are both consistent with improved skin and hair coat scores.

To examine how dietary n-3 polyunsaturated fatty acids affect Th2 cell development, female C57BL/6 mice were fed a washout corn oil (CO) diet for 1 wk followed by 2 wk of either the same CO diet or a fish oil (FO) diet. CD4+ T cells were isolated from spleens and cultured under both neutral (anti-CD3 and phorbol myristate acetate (PMA)) and Th2 polarizing conditions (anti-CD3 and PMA, in presence of rIL-4, rIL-2, and anti-IFN-γ) in the presence of homologous mouse serum (HMS) or fetal bovine serum (FBS) for 2 d. Dietary n-3 PUFA significantly enhanced Th2 cell development and suppressed Th1 development under neutral conditions as assessed by intracellular cytokine staining for IL-4 and IFN-γ as the two prototypic Th2 and Th1 cytokines, respectively. However, under Th2 polarizing conditions, while the suppression of Th1 cells was maintained in FO-fed mice, no dietary effect was observed in Th2 cells. Dietary FO increased the Th2/Th1 ratio under both neutral and Th2 polarizing conditions with HMS in the cultures. To examine the effect of dietary n-3 PUFA on Th1 development, DO11.10 Rag2-/- mice expressing transgenic T cell receptor specific for ovalbumin (OVA) peptide were used. CD4+ T cells were isolated from spleens and lymph nodes and stimulated with ovalbumin (OVA) peptide and irradiated BALB/c splenocytes in the presence of rIL-12, anti-IL-4, and rIL-2 in HMS for 2d. Cells were expanded for another 3 d in the presence of rIL-2 and rIL-12. Dietary n-3 PUFA did not affect Th1 differentiation as assessed by the proportion of IFN-γ+, IL-4- T cells in the cultures, but suppressed rIL-2 induced expansion. The suppressed expansion was due to suppressed proliferation (p<0.05). In vivo expansion of antigen-specific T cells was visualized by flow cytometric analysis of CFSE-positive transgenic T cells. Dietary n-3 PUFA did not appear to affect antigen-induced CD4+ T cell cycle progression in vivo. Overall, these results suggest dietary n-3 PUFA have no direct effect on Th2 cell development but do directly suppress Th1 cell development following both mitogenic and antigenic stimulation in vitro.

Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains ix, 124 p. : ill. Vita. Includes abstract. Includes bibliographical references.

Thesis (Ph. D.)--Chemical Engineering, Georgia Institute of Technology, 2004. / Lucian A. Lucia, Committee Member; Spyros G. Pavlostathis, Committee Member; Sujit Banerjee, Committee Chair; Yulin Deng, Committee Member; Howard L. Empie, Committee Member. Includes bibliographical references (leaves 146-155).

Thesis (doctoral)--Tallinn Technical University, 2001. / Includes bibliographical references (p. 59-64).