The effect of a maternal dietary lysine deficiency on milk carnitine levels and on plasma and liver carnitine levels in dams, fetuses and neonates was studied. Experimental animals were fed either a low-lysine diet (0.27% lysine), a high-lysine diet (1.07% lysine) ad libitum, or the high-lysine diet pair-fed to the low-lysine group. All diets contained 20% wheat gluten, 20% corn oil and negligible carnitine. Dams fed a diet, either low in lysine or restricted in total food intake, consumed significantly less food during pregnancy and lactation than high-lysine dams. When compared to high-lysine dams the low-lysine dams and their pair-fed controls gained significantly less weight during pregnancy and lost weight during lactation whereas the high-lysine dams gained weight during lactation. Litter size was not affected by either a dietary lysine deficiency or by the small reduction in total food intake during gestation. However, birth weight of offspring in the low-lysine and high-lysine restricted groups was significantly lower than that of the high-lysine controls. On day 15 of lactation the high-lysine pups weighed significantly more than the high-lysine restricted pups, which in turn weighed significantly mere than the low-lysine pups, suggesting a superior lactation performance for those dams fed the high-lysine control diet and the poorest lactation performance for those dams consuming the low-lysine diet. Liver and heart tissue samples were obtained from dams and their offspring on day 21 of pregnancy and day 15 of lactation. When liver weight or heart weight were expressed as a percentage of total body weight for dams or pups, no significant difference between dietary groups was detected. These results indicate that liver and heart weights were proportional to body weight. The low-lysine diet had no significant effect, on day 21 of gestation, on maternal plasma or liver carnitine levels or on fetal liver carnitine levels, whereas fetal plasma carnitine showed a small but significant increase compared to the high-lysine group. On day 15 of lactation plasma and liver carnitine levels were significantly higher in both dams and offspring fed the low-lysine diet, than in their respective controls. This increase in plasma and liver carnitine levels was probably due to a lowered food intake since animals fed the high-lysine diet pair-fed to the low-lysine group showed the same tissue carnitine response as did animals fed the low-lysine diet. Milk carnitine levels on day 2 of lactation were highest in the high-lysine group and lowest in the high-lysine restricted group. On days 8 and 15 of lactation milk carnitine levels were significantly higher in dams fed the low-lysine diet than in those fed the high-lysine or the high-lysine restricted diet. The results of this research indicate that plasma and liver carnitine levels in both dams and offspring and milk carnitine levels in dams, are not limited by the lysine content of the maternal diet under the experimental conditions of this study. / Land and Food Systems, Faculty of / Graduate

by Leung Cheuk Wa. / Thesis (M.Sc.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 97-106). / ACKNOWLEDGEMENTS --- p.i / LIST OF FIGURES --- p.v / LIST OF TABLES --- p.vi / SUMMARY --- p.1 / Chapter 1. --- INTRODUCTION --- p.3 / Chapter 2. --- BASIC ASPECTS OF CARNITINE / Chapter 2.1 --- BIOSYNTHESIS OF CARNITINE --- p.5 / Chapter 2.2 --- CARNITINE TRANSPORT --- p.8 / Chapter 2.3 --- THE ROLE OF CARNITINE IN INTRACELLULAR METABOLISM --- p.10 / Chapter 2.4 --- THE ROLE OF KIDNEY IN CARNITINE METABOLISM --- p.16 / Chapter 3. --- CARNITINE DEFICIENCY --- p.18 / Chapter 3.1 --- PRIMARY CARNITINE DEFICIENCY --- p.20 / Chapter 3.1.1 --- MYOPATHIC CARNITINE DEFICIENCY --- p.21 / Chapter 3.1.2 --- SYSTEMIC CARNITINE DEFICIENCY --- p.21 / Chapter 3.2 --- SECONDARY CARNITINE DEFICIENCY --- p.22 / Chapter 4. --- CARNITINE METABOLISM IN SELECTED DISEASES / Chapter 4.1 --- CARDIOMYOPATHY --- p.23 / Chapter 4.2 --- ORGANIC ACIDURIAS --- p.24 / Chapter 4.3 --- VALPROIC ACID THERAPY --- p.26 / Chapter 4.4 --- RENAL DIALYSIS ANDTRANSPLANTATION --- p.28 / Chapter 5. --- ANALYTICAL METHODS FOR CARNITINE ASSAYS --- p.30 / Chapter 6. --- DETERMINATION OF TOTAL AND FREE CARNITINE / Chapter 6.1 --- PRINCIPLE OF THE ASSAYS --- p.32 / Chapter 6.1.1 --- FREE CARNITINE DETERMINATION --- p.32 / Chapter 6.1.2 --- TOTAL CARNITINE DETERMINATION --- p.33 / Chapter 6.2 --- INSTRUMENTATION --- p.34 / Chapter 6.3 --- PREPARATION OF REAGENTS AND STANDARDS --- p.36 / Chapter 6.4 --- SPECIMEN COLLECTION --- p.42 / Chapter 6.5 --- SAMPLE PREPARATION --- p.43 / Chapter 6.6 --- ASSAY PROTOCOL FOR FREE CARNITINE --- p.44 / Chapter 6.7 --- ASSAY PROTOCOL FOR TOTAL CARNITINE --- p.46 / Chapter 6.8 --- FACTORS AFFECTING THE PERFORMANCE OF ASSAYS --- p.48 / Chapter 6.9 --- EVALUATION OF FREE AND TOTAL CARNITINE ASSAYS --- p.50 / Chapter 7. --- RESULTS OF EVALUATION OF TOTAL AND FREE CARNITINE ASSAYS / Chapter 7.1 --- CALIBRATION --- p.52 / Chapter 7.2 --- PRECISION --- p.55 / Chapter 7.3 --- LINEARITY RANGE --- p.56 / Chapter 7.4 --- RECOVERY --- p.58 / Chapter 7.5 --- INTERFERENCE OF ACETYLCARNITINE ON FREE CARNITINE ASSAY --- p.59 / Chapter 7.6 --- DISCUSSION --- p.59 / Chapter 8. --- STUDY IN NORMAL SUBJECTS / Chapter 8.1 --- SUBJECTS --- p.61 / Chapter 8.2 --- RESULTS OF THE NORMAL SUBJECTS --- p.61 / Chapter 8.3 --- DISCUSSION --- p.63 / Chapter 9. --- PATIENTS STUDY / Chapter 9.1 --- PATIENTS WITH CARDIOMYOPATHY / Chapter 9.1.1 --- SUBJECTS --- p.66 / Chapter 9.1.2 --- RESULTS OF THE STUDY --- p.66 / Chapter 9.1.3 --- DISCUSSION --- p.69 / Chapter 9.2 --- PATIENTS WITH METABOLIC DISEASES / Chapter 9.2.1 --- SUBJECTS --- p.71 / Chapter 9.2.2 --- RESULTS OF THE STUDY --- p.71 / Chapter 9.2.3 --- DISCUSSION --- p.74 / Chapter 9.3 --- PATIENTS ON VALPROIC ACID THERAPY / Chapter 9.3.1 --- SUBJECTS --- p.75 / Chapter 9.3.2 --- RESULTS OF THE STUDY --- p.75 / Chapter 9.3.3 --- DISCUSSION --- p.77 / Chapter 9.4 --- PATIENTS ON RENAL DIALYSIS AND AFTER TRANSPLANTATION / Chapter 9.4.1 --- SUBJECTS --- p.79 / Chapter 9.4.2 --- RESULTS OF THE STUDY --- p.79 / Chapter 9.4.3 --- DISCUSSION --- p.81 / Chapter 10. --- GENERAL DISCUSSION --- p.84 / Chapter 11. --- REFERENCES --- p.97