Armando Shimada

Effect of lycopene on lipid peroxidation and glutathione-dependent enzymes induced by T-2 toxin in vivo

Lycopene, obtained from fresh tomatoes, was incorporated into the chicks diet. The treatments were: (1) Control, (2) 1.5 mg T-2 toxin/kg body weight/day; (3) 25 mg lycopene/kg body weight/day, (4) 1.5 mg T-2 toxin plus 25 mg lycopene/kg body weight/day. Male broiler chicks, 7-28 days of age, were provided with feed and water ad libitum. Every 7 days, malondialdehyde (MDA) and glutathione (GSH) levels, and enzymatic activities of glutathione-S-transferase (GST), gamma-glutamyltransferase (GGT) and glutathione peroxidase (GP) were evaluated in liver homogenates. Compared to the controls after 7 days of treatment, T-2 toxin increased hepatic MDA concentration (128%). A significant consumption of endogenous antioxidant GSH (45%) was induced as well as a marked increase in hepatic enzymatic activities of GST, GGT, and GP (312, 187, and 324%, respectively). Addition of T-2 plus lycopene, at an approximate ratio of 1:17 in the diet, diminished some parameters measured (P < 0.05). Apparently lycopene participated as an antioxidant agent and also protecting the cellular level of GSH.

Effect of dietary protein:energy ratio on intake, growth and metabolism of juvenile green abalone Haliotis fulgens

Abstract Juvenile green abalone Haliotis rufescens were grown under laboratory conditions at 21±1 °C and fed formulated diets consisting of different protein:energy ratios (mg protein/kcal), 62, 74, 85, 100, 108, for 60 days. The level of crude protein ranged from approximately 26% to 44% while the energy content remained constant at about 4.1 kcal g −1 . Growth ranged from 3.63 to 12.33 mg day −1 . The growth of abalone fed the 100 and 108 diets was significantly greater than that of each of the other diets. Protein efficiency ratio increased as the dietary protein content increased except for the T108 diet (44% crude protein). Abalone apparently consume food to satisfy an energy requirement. Caloric expenditure due to metabolism was estimated for abalone fed diets with protein ratios of 62, 85, 100. Energy loss due to respiration did not vary appreciably among abalone fed the different diets. The proportional distribution of dietary energy into fecal, digestible, growth, and metabolic energy was estimated for abalone fed these diets. Apparent dry matter digestibility was among the lowest for abalone fed the 100 P:E diet, but growth of abalone fed this diet was significantly higher than that of each of the other treatments except the 108 diet. Unexplained energy loss to achieve balance ranged from 7% to 28.5%, some of which is probably due to differential mucus and ammonia production. Results suggest a potential for the reduction of both dietary protein and lipid without causing any adverse effects on the growth response.

Induction of peroxisomal proliferator-activated receptor γ and peroxisomal proliferator-activated receptor γ coactivator 1 by unsaturated fatty acids, retinoic acid, and carotenoids in preadipocytes obtained from bovine white adipose tissue

The importance of dietary fat components, such as fatty acids, in the expression of multiple genes is clear. In the case of beef cattle, fat in the form of fatty acids (saturated or unsaturated), vitamin A (mainly retinoic acid), or carotenoids (beta-carotene and lutein) is obtained from dietary feed or pasture. The aim of this work was to study the effect of fatty acids (phytanic and pristanic acids), vitamin A (all-trans and 9-cis retinoic acid), and carotenoids (beta-carotene and lutein) on the expression of PPARgamma and its coactivator PGC-1alpha during differentiation of bovine white adipose tissue. Samples were collected at slaughter from subcutaneous adipose tissue and processed in a solution containing type II collagenase for 2 h at 37 degrees C. Cells were resuspended in basal medium, Dulbeccos modified Eagles medium containing 5% fetal bovine serum, plated on 24-well culture plates at a density of 1 x 10(4) cells/cm(2), and incubated at 37 degrees C in a 5% CO(2) atmosphere. Preadipocyte differentiation after reaching confluence was induced by various treatments: rosiglitazone (20 microM); unsaturated fatty acids: phytanic acid (25, 50, 100 microM) and pristanic acid (25, 50, 100 microM); retinoids: 9-cis retinoic acid (0.5, 0.75, 1 microM) and all-trans retinoic acid (0.5, 0.75, 1 microM); and carotenoids: beta-carotene (10, 20, 30 microM) and lutein (10, 20, 30 microM). Expression of PPARgamma and PGC-1alpha was measured in differentiated cells. Phytanic acid, all-trans retinoic acid, and 9-cis retinoic acid were the best activators of PPARgamma expression, and the combination of 9-cis and all-trans retinoic acid was the best activator of PGC-1alpha expression (P < 0.05). Therefore, these are powerful agents for the promotion of bovine adipogenesis and constitute promising compounds to be used in bovine fattening.

Bovine sirtuins: initial characterization and expression of sirtuins 1 and 3 in liver, muscle, and adipose tissue.

Sirtuins, the mammalian homologs of the silent information regulator 2 gene of Saccharomyces cerevisiae, are members of the NAD(+)-dependent family of histone deacetylases. In vertebrates, 7 sirtuins have been described, with different cellular localizations and target proteins. Glucose and lipid metabolism are among the processes regulated by these enzymes. In ruminants, gluconeogenesis is the main biochemical pathway by which glucose is obtained. Because sirtuins in bovines have not been studied, the aim of this work was to obtain sequences coding for the 7 sirtuins and determine the expression patterns of sirtuin1 (Sirt1) and sirtuin3 (Sirt3) in the liver, muscle, and adipose tissue of calves and bulls. Using PCR amplification, we obtained sirtuin gene sequences and reported them to the National Center for Biotechnology Information GenBank. Characteristic sequence motifs corresponding to the sirtuin catalytic core domain were found, including the active and zinc-binding sites. Relative expression patterns of Sirt1 and Sirt3 in liver, muscle, and adipose tissue were quantified by real-time PCR, normalizing to the geometric mean of the housekeeping genes cyclophilin A and β-actin. Expression of Sirt1 was less in liver and muscle, whereas it was greater in adipose tissue of adult animals, with statistical differences (P=0.0071) only in the latter. In the case of Sirt3, expression was greater in all 3 adult tissues, but statistical differences were found only in liver (P=0.0141) and muscle (P=0.0017). The greatest expression was observed in liver for Sirt1 and in muscle for Sirt3, whereas the least expression was in muscle for Sirt1 and in adipose tissue for Sirt3. In other species, sirtuin expression (both Sirt1 and Sirt3) in liver is reported to be the greatest among these 3 tissues, a pattern different from what we measured. These differences in expression can be associated with metabolic differences between nonruminant and ruminant species. However, further research on the relationship between bovine sirtuins and ruminant metabolism is required for a better understanding of these fields.

Methods of measuring feed digestibility in the green abalone (Haliotis fulgens)

Abstract Various methods of calculating feed digestibility in the green abalone were compared. The total fecal collection technique was evaluated by comparing it with two different marker methods, one external (chromic oxide) and one internal (acid-insoluble ash). To obtain this information, a funnel-shaped digestibility chamber was designed. All the chambers (experimental units) were suspended in a square tank (200-l capacity) containing aerated seawater and with airflow and temperature kept constant (0.5 l/min, 19±0.5 °C). Two abalone (2 years old; 4.8±0.69 cm; 14.1±6.04 g) were placed in each chamber. All animals were fed daily with a similar diet containing 1% chromic oxide. After 1 week of acclimatization to the chambers and the experimental diet, feces were collected for the next 45 days to ensure that there were sufficient samples to perform all the evaluations. The results showed that the digestibility coefficients obtained with total collection and with acid-insoluble ash marker were similar (80.5±2.73% vs. 84.4±5.21%, respectively), whereas using a chromic oxide marker produced a significantly lower value (61.7±2.0%). The advantages and disadvantages of each technique are discussed. We also suggest some modifications to enable the acid-insoluble ash method to be run using a smaller sample size (200 mg).

In vitro and in situ disappearance of β-carotene and lutein from lucerne (Medicago sativa) hay in bovine and caprine ruminal fluids

Two experiments were conducted to determine the rumen fluid disappearance rates (kd) of β-carotene, lutein, total carotene and total xanthophyll from lucerne (Medicago sativa) hay, in two ruminant species: Brahman steers (fat-pigmenting) and Granadine goats (non-pigmenting). Within species, the in vitro and the in situ methods were compared. The concentration of carotenoid compounds was determined by spectrophotometry and high performance liquid chromatography. The in vitro disappearance trends were linear for all compounds (P<0.01). β-carotene kd were 0.13 and 0.37; lutein, 0.20 and 0.25; total carotene, 0.20 and 0.62 and total xanthophyll, 0.30 and 0.77 h −1 for steers and goats, respectively. The in situ disappearance trends were quadratic (P<0.01). Dry matter kd were 1.9 and 1.5% h−1; cellular content, 2.0 and 2.3; β-carotene, 2.5 and 1.2; lutein, 2.5 and 1.5; total carotene, 2.2 and 1.0 and total xanthophyll, 2.1 and 1.1% h−1 for steers and goats, respectively. The large disappearance rates of carotenoids observed in the in situ method vs the virtual absence of disappearance in the in vitro method in both species, can be related to the dry matter and cellular content kd. These results suggest that carotenoids disappear probably by joining the cellular content and not by their direct destruction or by attack from the ruminal microorganisms, and the ruminal disappearance is independent of the species studied. © 1999 Society of Chemical Industry

Presence of fed β-carotene in digesta, excreta, blood, and hepatic and adipose tissues of Holstein steers

Eight animals were fed a diet without added β-carotene for 49 d and then supplemented with four levels of β-carotene (0, 5.5, 44 or 352 mg kg–1dry matter) for 30 d; the two-phase procedure was then repeated. Steers were killed at the end of the second period. Concentrations of β-carotene were: 0, 0, 227.2 and 2011 mg dL–1 (P 0.1). The estimated β-carotene digestibilities were 66.25, 84.39 and 88.14% for treatments with 5.5, 44 and 352 mg β-carotene kg–1 DM, r...

GROWTH AND ENERGY UTILIZATION OF JUVENILE PINK ABALONE HALIOTIS CORRUGATA FED DIETS CONTAINING DIFFERENT LEVELS OF PROTEIN AND TWO STARCH:LIPID RATIOS

Abstract Juvenile pink abalone Haliotis corrugata (initial mean length = 10.7 ± 0.3 mm; initial mean weight = 0.15 g) were grown under laboratory conditions in an aerated flow-through seawater system at 21 ± 1°C. For 131 days, abalone were fed diets containing three different levels of protein (42%, 36% and 32%), each level containing two ranges of starch:lipid ratios (1.5–1.8 or 3.2–3.6). The gross energy content of the diets ranged from 4.26–3.68 kcal/g. Within a particular protein level, growth did not differ significantly. When dietary protein levels exceeded 32%, a trend of higher growth of abalone was observed for dietary treatments that contained lower levels of lipid (higher starch to lipid ratios). The amount of protein consumed daily for the 32% dietary protein is apparently insufficient to meet requirements for energy and maximum growth. No notable diet-dependent differences in the proportional composition (dry weight) of the shell and the soft tissue, and the energy content of the soft tissue were observed. Daily food intake and consumed energy were significantly different among treatments, being inversely related to the calculated P:E ratios. The increased consumption may have been somewhat overestimated because of loss arising from lower water stability of the diets. Ammonia excretion ranged from 7.9–4.8 μg NH4+ /h /g abalone but was not significantly different among treatments except for the treatment containing 32% crude protein and a low carbohydrate:lipid ratio. Specific Dynamic Action (SDA) comprised nearly 50% of measured oxygen consumption and did not significantly differ among treatments. Respiration increased during the night showing a typical circadian pattern reported in Haliotis genera. Measured mucus production did not vary among treatments. Carbohydrate preferentially serves as the principal energy source and a consistent amount of dietary protein is also used as an energy source, regardless of dietary protein content. Within a developed energy budget, approximately 70% of the ingested energy was lost through feces, and approximately 25% of the ingested energy was metabolized, with 7% to 10% channeled to growth. A direct determination of available digestible energy was not possible because of the inability to collect sufficient feces to estimate fecal energy. The results suggest that practical diets should include levels of dietary protein that are approximately 35% protein to meet requirements for energy and maximum growth. In addition, carbohydrates seem to be the preferred energy source and lipid levels should be minimized to the extent that essential fatty acids requirements are met.

Ghrelin stimulates myogenic differentiation in a mouse muscle satellite cell line and in primary cultures of bovine myoblasts

Ghrelin is an acylated hormone that influences food intake, energy metabolism and reproduction, among others. Ghrelin may also stimulate proliferating myoblast cell differentiation and multinucleated myotube fusion. The aim of this work was to assess the effect of human ghrelin (hGHRL) and human ghrelin fragment 1-18 (hGHRL1-18) on myoblast differentiation by means of mRNA expression and protein level. Two types of cells were tested, the cell line i28 obtained from mouse skeletal muscle and primary cultures of bovine myoblasts. Both ghrelin and its N-terminal fragment hGHRL1-18 were used at concentrations of 0, 0.01, 0.1, 1, 10 and 100 nm. Treatments were applied to pre-confluent cultures and were maintained for 4 days. We determined that between 0.1 and 100 nm, hGHRL and hGRHL1-18 had similar effects on myogenic differentiation of i28 cells (p < 0.01). On the other hand, only the higher concentrations (10 and 100 nm) of hGHRL stimulated bovine myoblast differentiation. These results could be attributed to the presence, in both i28 cells and in bovine myoblasts, of the mRNA for GHS-R1a and CD36 receptors. The use of ghrelin in livestock production is still questionable because of the limited effects shown in this study, and additional research is needed in this field.

The effect of NH3 and/or SO2 on the compositional and histological characteristics of sorghum stover

Abstract Two experiments were conducted to determine the effects of chemical treatments on the compositional and histological characteristics of sorghum stover. In Experiment 1, chopped sorghum stover was placed inside plastic bags, where 5% of either NH 3 applied as ammonium hydroxide or SO 2 applied as gas, was injected. After 21 days in contact with the respective gas, bags were opened, aerated for 7 days and prepared for chemical analysis and microscopical observations. Compared with an untreated control, treatment with NH 3 increased total nitrogen, non-protein nitrogen, protein nitrogen, acid detergent fiber nitrogen, and in vitro dry matter disappearance and decreased the acid detergent fiber (ADF) contents of stover; SO 2 -treated stover had a lower ADF content. In Experiment 2, each chemical was applied to stover previously treated with the alternate gas. In general, the compositional effects followed the same trend as in the previous experiment, although they seemed to be more severe. Scanning electron microscopy showed the extent of the stover tissue damage inflicted by the chemical additives applied.