Changes in hormones, growth factor and lipid metabolism in finishing pigs fed betaine

An experiment was conducted to investigate the effect of dietary betaine supplementation on carcass characteristics, hormones, growth factor and lipid metabolism in finishing pigs. Forty-eight crossbred barrows and gilts (Seghers × Seghers × Duroc) weighing about 55 kg were divided into two groups, each with three replicates of eight pigs (four barrows and four gilts) per replicate, and fed corn–soybean meal basal diets supplemented with 0 and 0.125% betaine for 42 days. At trial termination, two pigs (one barrow and one gilt) weighing about 90 kg were selected from each replicate and slaughtered for analyses. The results showed that betaine increased carcass lean percentage and longissimus muscle area by 5.19% (P < 0.01) and 17.85% (P < 0.01), respectively, and decreased carcass fat percentage and average backfat thickness by 13.07% (P < 0.01) and 10.30% (P < 0.05), respectively. Serum growth hormone, insulin-like growth factor I, free triiodothyronine, free thyroxine and insulin levels in pigs fed betaine were elevated by 45.61% (P < 0.01), 55.50% (P < 0.01), 57.95% (P < 0.01), 51.80% (P < 0.01) and 42.34% (P < 0.05), respectively. Fatty acid synthase activity in the 10th rib subcutaneous adipose tissue was decreased by 24.35% (P < 0.05) with betaine supplementation, whereas hormone-sensitive lipase activity was significantly increased (P < 0.05). Meanwhile, serum free fatty acids concentration in betaine-fed pigs was 25.75% higher compared to controls (P < 0.01). The study suggested that betaine could induce changes in hormones and growth factor in finishing pigs, and therefore could inhibit fat synthesis through reducing lipogenic enzymes activities and promote fat degradation by increasing hormone-sensitive lipase activity, with a resultant decrease in adipose tissue mass and improvement in carcass characteristics.     

Tissue-specific antioxidative and neurotoxic responses to diazinon in Oreochromis niloticus

The purpose of this study was to evaluate oxidative stress and neurotoxic potential of organophosphorus (OP) insecticide diazinon in the sentinel freshwater fish, Oreochromis niloticus. Antioxidant and acetylcholinesterase (AChE) enzyme activities and malondialdehyde (MDA) and protein levels were measured spectrophotometrically in gill, kidney, alimentary tract, and muscle tissues of fish treated with sub-lethal diazinon concentrations for 1, 7, 15, and 30 days. Dose-dependent inhibitions of AChE were observed in all the experimental fish. On the contrary of alimentary tract, MDA levels were elevated in kidney and muscle and gill was not affected. AChE and MDA levels intercorrelated in kidney and muscle tissues. Diazinon had increased superoxide dismutase (SOD) activities in all the tissues, while kidney was the most affected tissue. Tissue-specific alterations were observed on catalase (CAT) and glutathione peroxidase (GPx) activities; however, the activities were not changed in gill and muscle tissues for GPx and in gill, muscle, and kidney tissues for CAT. Protein levels decreased in kidney, muscle, and alimentary tract, while increased in gill and alimentary tract in 15 days. With respect to these results, diazinon has oxidative and neurotoxic potentials in O. niloticus. Observed changes with diazinon treatment were generally tissue-specific and dose-dependent.     

Antioxidant and stomatal responses of grapevine (Vitis vinifera L.) to boron toxicity

Although of considerable agronomic importance, our understanding of B toxicity mechanism in plants is still not completely understood, and remains an open question. Therefore, we investigated the effect of increasing levels of B (0, 10, 20 and 30 mg kg⁻¹) on the growth, boron (B) concentrations, stomatal resistance, lipid peroxidation (MDA), membrane permeability (MP), lypoxygenase activity (LOX), proline (PRO) and H₂O₂ accumulation, and the activities of major antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT and ascorbate peroxidase, APX) of grapevine (Vitis vinifera L. cv. Kalecik Karasi) grafted on 5BB rootstock (V. berlandieri × V. riparia) was investigated. Applied toxic levels of B significantly reduced leaf and root growth and increased the B concentration of the leaf, and stem, bark and root of rootstock. In the all B levels leaf tissues of grapevine accumulated more B than that of the other plant parts. In order to restrict excessive uptake of B, stomatal resistance of the leaves increased especially at high B treatments (20 and 30 mg kg⁻¹). The concentrations of H₂O₂, MDA and membrane permeability were increased as the result of B toxicity while proline and the activity of lypoxygenase were decreased. Compared with control plants, the activities of SOD and CAT were increased by B treatments while the activity of APX was decreased. To our knowledge, this is the first report that B toxicity elevated the antioxidant enzymes to protect the membrane functions from reactive oxygen species (ROS) injury in grapevine and it was hoped that this study would provide a basis for developing strategies for reducing the risks associated with B toxicity.     

A comparative study of the metabolic effects of hypertrehalosemic hormone and 1,2,3,4,5,6-hexachlorocyclohexane (γ-HCH) in the American cockroach, Periplaneta americana

Several effects of hypertrehalosemic hormone (Peram-HTH) have been compared with the action of 1,2,3,4,5,6-hexachlorocyclohexane (γ-HCH) in the cockroach, Periplaneta americana. The data show that both agents stimulate respiration while maintaining an R.Q. of approximately 1. The action of γ-HCH differs from that of Peram-HTH-I in that it promotes oxidation of large amounts of soluble carbohydrate. Recent studies show that Peram-HTH-I has an equally potent stimulatory effect on lipid deposition in the fat body and on the release of trehalose from the same tissue. It is of interest that γ-HCH not only increases triacylglycerol accumulation in the fatγ body but that this effect is more pronounced if the γ-HCH is applied to the ventral surface of the mesothorax. γ-HCH also depleted whole body glycoprotein and glycolipid whereas Peram-HTH-I had no effect on glycoprotein but increased that of glycolipid. It is clear that γ-HCH causes complex disruptions to the metabolism of the insect, many of which are related to the release of hormones. The study supports the idea that certain actions of γ-HCH are mediated through the release of Peram-HTH-I.     

A review on the mechanisms involved in hyperglycemia induced by organophosphorus pesticides

Organophosphorus (OP) compounds are cholinesterase-inhibiting chemicals used as pesticide. Exposures to OPs cause a significant number of poisonings and deaths each year. One of the reported adverse effects in human exposure to OPs is hyperglycemia. Animal studies have also shown altered glucose homeostasis following acute or chronic exposures to OPs. The objective of this paper is to provide a brief review of the mechanisms involved in the OP-induced glucose homeostasis alteration. To reach this objective, a search of the literature using Medline/Index Medicus, Scopus, and Chemical Abstract were performed, most of relevant citations were studied and summarized. To better understand the nature of glucose homeostasis, the principles of glucose production, metabolism, and its hormonal control have been discussed. Collection of theses studies support the conclusion that hyperglycemia is the outcome of acute or chronic exposure to OPs. OPs can influence body glucose homeostasis by several mechanisms including physiological stress, oxidative stress, inhibition of paraoxonase, nitrosative stress, pancreatitis, inhibition of cholinesterase, stimulation of adrenal gland, and disturbance in metabolism of liver tryptophan.     

不同贮藏条件鸡蛋的脂类过氧化作用

本文以ＴＢＡ光度法分析了不同贮藏条件下鸡蛋脂类的过氧化作用,并分析了温度、氧对过氧化作用的影响。结果表明,在贮藏条件下,鸡蛋蛋黄中伴有明显的脂类过氧化过程。脂类过氧化物（ＬＰＯ）的水平随贮藏时间的延长而不断增加（Ｐ＜０．０１）,但蛋清中的ＬＰＯ在贮藏过程中没有明显的变化。低温和缺氧可明显抑制鸡蛋脂类的过氧化作用（Ｐ＜０．０１）。     

鸡马杜霉素急性中毒及其脂质过氧化关系的研究

本文在实验条件下人工诱发鸡马杜霉素急性中毒，观察中毒症状及病理变化，测定受损靶器官的脂质过氧化物的含量及相关酶的活性，以及肝细胞色素Ｐ－４５０的含量。实验结果表明：鸡马杜霉素急性中毒的主要临床症状是腹泻、腿无力或麻痹；肉眼病变是全身性充血、淤血及少数组织出血；显微镜检病变是肝脏、心肌及腿肌出血与变性；肝脏的脂质过氧化物的含量及过氧化氢酶的活性显著增加；肝Ｐ－４５０的含量显著增加；但是心肌与腿肌的脂     

Bioaccumulation of cadmium and its biochemical effect on selected tissues of the catfish (<Emphasis Type="Italic">Clarias gariepinus</Emphasis>)

The present study examines the pattern of accumulation of cadmium (Cd) and its biochemical effects on selected tissues of a variety of African catfish (Clarias gariepinus), after exposure to various doses of Cd. The results obtained indicate that at the end of 21 days of exposure, the total tissue organ cadmium concentration followed the pattern kidney > gill > liver > muscle for each of the exposure concentrations. The levels of Cd in these organs were higher than those in ambient water. Moreover, while the rate of uptake of Cd increased with time in the kidney, liver and muscle, it decreased in the gill. Superoxide dismutase (SOD) was significantly elevated only in the kidney of catfish treated with 0.2 and 0.4 ppm of Cd for 7 days compared with the control. Conversely, gill SOD was significantly decreased in the same concentrations of Cd-treated catfish relative to the control. Statistically similar levels of SOD were observed in the liver, brain and muscle with all the treatments after the same duration of treatment. In the fish exposed for 21 days, SOD activity was significantly decreased in the kidney with a corresponding increase in lipid peroxidation (LPO), but it manifested only with the 0.2- and 0.4-ppm Cd treatment relative to the control. In the liver, however, Cd exposure significantly increased SOD in the 0.2- and 0.4-ppm treatments of the same duration. In conclusion, the present study indicates that the accumulation of Cd and its effect on SOD and LPO in C. gariepinus is dependent on concentration, tissue and time     

动物脂肪代谢激素调控分子机理的研究进展

激素对脂肪代谢调节机理的共同特点是一方面通过自身的受体介导，另一方面又通过干扰其它激素的信号传导通路的某个环节来发挥作用。其作用既可从ＤＮＡ水平 上调节相关基因的表达和ｍＲＮＡ水平上调节转录物的稳定性，也可从蛋白质水平上通过磷酸化来调节酶及相关蛋白质的活性。不同水平的调节作贯穿于整个脂肪代谢及其它物质代谢的相互作用之中，也就构成了脂肪代谢研究的独特性和复杂性，及其与其它代谢研究的不可分割性。