Influence Of Dietary Methionine Research Articles

The optimum dietary methionine requirement of juvenile humpback grouper (Cromileptes altivelis): effects on growth, micromorphology, protein and lipid metabolism.

An 8-week feeding trial was conducted to evaluate optimum dietary methionine (Met) requirement of juvenile humpback grouper (Cromileptes altivelis) and the influence of dietary methionine (Met) supplementations on growth, gut micromorphology, protein and lipid metabolism. Seven isoproteic (48.91%) and isolipidic diets (10%) were made to contain 0.70, 0.88, 1.04, 1.27 1.46, 1.61 and 1.76% of dry matter Met levels. Results showed that lower survival, weight gain (WG%), protein efficiency ratio (PER), protein productive value (PPV) but higher daily feed intake (DFI) and feed conversion ratio (FCR) were observed in the Met deficient groups (0.70 and 0.88%). Optimum dietary Met requirement for humpback grouper was found to be 1.07% through the straight-broken line analysis of WG% against Met. Fish fed Met deficient diets (0.70, 0.88%) exhibited lower mRNA levels of growth hormone (GH), growth hormone receptor (GHR), insulin-like growth factor-I (IGF-1), target of rapamycin (TOR) as well as S6 kinase 1 (S6K1) than other dietary groups. Whereas, expression of genes related to general control nonderepressible (GCN2) kinase i.e., GCN2 and C/EBPβ enhancer-binding protein β was upregulated in fish fed low Met diets (P < 0.05). The mRNA expression of hepatic fatty acid synthase (FAS) and sterol regulatory element-binding protein-1 (SREBP-1) were higher in fish fed 0.70 and 0.88% dietary Met group and the lipolytic genes, hepatic peroxisome proliferator-activated receptor α (PPARα) and carnitine palmitoyl transferase-1 (CPT-1) showed an opposite variation tendency as FAS or SREBP1. Generally, the optimum Met requirement for humpback grouper was predicted to be 1.07% of dry matter.

Influence of Dietary Methionine, Folic Acid and Cyanocobalamin and Their Interactions on the Performance of Broiler Breeder

Influence of Dietary Methionine, Folic Acid and Cyanocobalamin and Their Interactions on the Performance of Broiler Breeder

Influence of dietary methionine with or without adequate dietary vitamins on hyperhomocysteinemia in rats

Information on the effects of dietary vitamins involved in homocysteine metabolism on the dietary methionine (Met)-induced hyperhomocysteinemia is limited. Thus, a six-wk study was conducted to investigate the effects of dietary Met with or without adequate vitamins on plasma total homocysteine (tHcy) in rats. Four levels of supplemental L-Met (0, 5, 10 and 20 g/kg) and two levels of vitamins (adequate and deficient in folate plus B-12) were tested in the casein-based diets. The plasma tHcy values in males were higher (p < 0.05) than in females (8.1± 0.6 vs. 6.0±0.6 μmol/L for adequate diet; 66.5± 1.4 vs. 45.5±0.9 μmol/L for folate-B-12 deficient diet). In males, supplementation of the adequate (control) diet with 5, 10 and 20 g/kg Met, increased tHcy to 1.3, 1.9 and 7.9 times control, respectively. In females, the corresponding values were 1.3, 1.7 and 5.6 times control. In rats fed folate-B-12 deficient diets, supplemental Met, however, generally caused reductions in plasma tHcy values in both sexes. These disparate responses to supplementary Met could be partly due to increases in hepatic S-adenosylmethionine (SAM)/ S-adenosylhomocysteine (SAH) ratios in folate-B-12 deficient rats.

Influence of dietary methionine on body weight gain and composition in high-lean growth gilts fed from 100 to 240 lb (1994)

Influence of dietary methionine on body weight gain and composition in high-lean growth gilts fed from 100 to 240 lb (1994)

Influence of Dietary Methionine on the Metabolism of Selenomethionine in Rats

To determine the influence of methionine on selenomethionine (SeMet) metabolism, weanling male rats were fed for 8 wk a basal diet marginally deficient in sulfur amino acids, containing 2.0 micrograms selenium (Se)/g as DL-SeMet and supplemented with 0, 0.3, 0.6 or 1.2% DL-methionine. Increased dietary methionine caused decreased selenium deposition in all tissues examined but increased glutathione peroxidase (GSHPx, EC 1.11.1.9) activity in testes, liver and lungs. A positive correlation was found between dietary methionine and the calculated percentage of selenium associated with GSHPx. In a second experiment, 75SeMet was injected into weanling male rats which had been fed the basal diet containing 2.0 micrograms selenium as DL-SeMet with or without the addition of 1.0% methionine. The selenoamino acid content of tissues and the distribution of 75Se in erythrocyte proteins were determined. In comparison to the rats fed the basal diet without added methionine, significantly more 75Se-selenocysteine was found in liver and muscle, more 75Se was found in erythrocyte GSHPx and less 75Se was found in erythrocyte hemoglobin of rats fed 1.0% methionine. These data suggest that methionine diverts SeMet from incorporation into general proteins and enhances its conversion to selenocysteine for specific selenium-requiring proteins, such as GSHPx.

Influence of dietary methionine on rat growth and thyroid activity

Une diete contenant 2.8% de methionine a reduit la croissance et l'activite thyroidienne du rat. La restriction de nourriture appliquee a des rats normaux a donne des resultats comparable. L'augmentation de la cystine dans cette diete pour obtenir le meme taux de soufre n'a pas altere la croissance ou l'activite thyroidienne comparee a celle des rats normaux. En conclusion, la reduction de l'activite thyroidienne des rats recevant un exces de methionine est due a une insuffisance de nutrition.

Influence of dietary methionine on dieldrin metabolism in rats

Influence of dietary methionine on dieldrin metabolism in rats

Influence of dietary methionine on metabolism of DDT in the rat.

Influence of dietary methionine on metabolism of DDT in the rat.

The influence of dietary methionine on the amino acid pool of Hymenolepis diminuta in the rat's intestine.

The amount of [14C]methionine in the stomach, anterior and posterior intestine wall and lumen, blood and caecum of a rat, and in the anterior and posterior parts of the tapewormHymenolepis diminutain the intestine, was measured at intervals from 10 min to 10 h after feeding a meal of 2 g glucose and 37.5 mg methionine by stomach tube.Nearly all the meal left the stomach within 5 h; the amount entering the tapeworm depended on the position of the worm. That part lying in the anterior half of the intestine was subjected to a rapid influx reaching a maximum concentration of at least 8 mM within 1–3 h after the meal was administered. The level in the worm then dropped to about 20 % of the peak level, although the stomach was still emptying and the level of methionine in the intestine wall was still rising. This was a stable state, and equal to the concentration in the posterior part of the worm which was reached 2 h after the rat was fed.The reason why the anterior part of the worm should show a big influx and efflux is discussed and related to changes in concentration of methionine in the lumen. The lack of such a flux into and out of the worm further down the intestine is related to the host's homeostatic control of amino acid balance in the intestine.The results prove that dietary imbalance of amino acids affect the amino acid pool in a tapeworm for about 3 h, if it lies in the anterior of the gut. A dietary regime is suggested which should produce a prolonged effect and thereby retard growth of the worm.The weights of the parts of the worms found in the anterior and posterior half of the small intestine revealed an unexpected phenomenon; the majority of the tapeworm, by weight, lies in the anterior of the intestine for about 4 h following a meal, but in the posterior of the intestine after the stomach has emptied.It is a great pleasure to thank Miss Gillian Moore and Miss Patricia Grant for technical assistance, and Shell International Petroleum Company, London, for financial support.

Radiation and Wound Healing: Influence of Dietary Methionine and Zinc on Zinc-65 Distribution and Excretion in the Rat

to promote the healing of excised wounds in nonirradiated rats (13). Either methionine alone or zinc alone as feed additives produced no consistent changes in the healing rate. Recently, Savlov et al. (14) have found that incised wounds preferentially accumulate zinc-65 during the acute healing stage. Too, significant alterations in zinc metabolism have been reported to occur in rats (15, 16) and mice (17, 18) after whole-body exposure to ionizing radiation. Available evidence suggests, therefore, that radiation exposure causes an alteration in zinc metabolism; this alteration in turn may be responsible for impaired wound healing. The purpose of the present investigation was to observe how addition of dietary methionine or zinc, or both, influences the distribution and excretion of zinc-65 in irradiated and nonirradiated wounded albino rats.