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1.
Abdel-Massih RM Rizkallah HD Al-Din RS Baydoun EA Brett CT 《Journal of plant physiology》2007,164(1):1-10
Microsomal membranes were prepared from etiolated pea (Pisum sativum L.) epicotyls and used to form nascent [Uronic acid-14C]pectin. The enzyme products were characterized by selective enzymic degradation, gel permeation chromatography and analysis of cellulose binding properties. The product obtained had a molecular weight of around 40 kDa, which was significantly lower than that of nascent [Gal-14C]pectin prepared from the same tissues. It is composed mainly of polygalacturonan and perhaps also rhamnogalacturonan (RG-I). Evidence was obtained for the presence of a protein attached to the nascent [Uronic acid-14C]pectin, but it was unaffected by endoglucanase and did not bind to cellulose. Hence, no xyloglucan appeared to be attached to the nascent [Uronic acid-14C]pectin. A model is proposed in which xyloglucan is attached to nascent pectin after formation of homogalacturonan, but before the pectin leaves the Golgi apparatus. 相似文献
2.
Chwalibog A Tauson AH Ali A Matthiesen C Thorhauge K Thorbek G 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2007,146(3):305-309
The experiment comprised 48 chicken (Gallus gallus) embryos from a modern, fast growing line, Ross 308 (RO) and 48 from a slow growing line, Labresse (LA). The O(2) consumption and CO(2) production were measured in an open-air-circuit respiration unit, and heat production (HE) from embryos was calculated at an age of 10, 13, 16 and 19 days. Gas exchange was below 10 ml/h for RO and LA by an age of 10-13 days, increasing steeply to a "peak" on day 16 and then slowing down between 16 and 19 days. The pattern of curves for gas exchange was identical for RO and LA, but on a lower level for LA. HE followed the pattern of gas exchange, with a mean around 50 J/h on day 10, increasing to 528 (RO) and 402 (LA) J/h on day 19. The main source of HE was oxidized fat. In addition to respiration experiments chemical analyses were carried out on 60 eggs from RO and 60 from LA. Prior to chemical analyses the eggs were incubated for 7, 13 and 19 days. Since fat oxidation was the main energy fuel the content of fat in the eggs decreased by 2.0 (RO) and 1.6 g (LA), while protein content was fairly constant in each line. It is remarkable that the differences in heat production between chickens from fast and slow growing lines were already manifested during their embryonic development. 相似文献
3.
Matthiesen CF Blache D Thomsen PD Tauson AH 《Animal : an international journal of animal bioscience》2012,6(1):50-60
Foetal life malnutrition has been studied intensively in a number of animal models. Results show that especially foetal life protein malnutrition can lead to metabolic changes later in life. This might be of particular importance for strict carnivores, for example, cat and mink (Neovison vison) because of their higher protein requirement than in other domestic mammals. This study aimed to investigate the effects of low protein provision during foetal life to male mink kits on their protein metabolism during the early post-weaning period of rapid growth and to investigate whether foetal life protein deficiency affects the response to adequate or deficient protein provision post weaning. Further, we intended to study whether the changes in the gene expression of key enzymes in foetal hepatic tissue caused by maternal protein deficiency were manifested post-weaning. A total of 32 male mink kits born to mothers fed either a low-protein diet (LP), that is, 14% of metabolizable energy (ME) from protein (foetal low - FL), n = 16, or an adequate-protein (AP) diet, that is, 29% of ME from protein (foetal adequate - FA), n = 16) in the last 16.3 ± 1.8 days of pregnancy were used. The FL offspring had lower birth weight and lower relative abundance of fructose-1,6-bisphosphatase (Fru-1,6-P2ase) and pyruvate kinase mRNA in foetal hepatic tissue than FA kits. The mothers were fed a diet containing adequate protein until weaning. At weaning (7 weeks of age), half of the kits from each foetal treatment group were fed an AP diet (32% of ME from protein; n = 8 FA and 8 FL) and the other half were fed a LP diet (18% of ME from protein; n = 8 FA and 8 FL) until 9.5 weeks of age, yielding four treatment groups (i.e. FA-AP, FA-LP, FL-AP and FL-LP). Low protein provision in foetal life lowered the protein oxidation post-weaning compared with the controls (P = 0.006), indicating metabolic flexibility and a better ability to conserve protein. This could not, however, be supported by changes in liver mass because of foetal life experience. A lower relative abundance of Fru-1,6-P2ase mRNA was observed (P < 0.05), being lower in 9.5-week-old FL than in FA kits. It can be concluded that foetal life protein restriction leads to changes in post-weaning protein metabolism through lower protein oxidation of male mink kits. 相似文献
4.
Zahran MA Salem TA Samaka RM Agwa HS Awad AR 《Bioorganic & medicinal chemistry》2008,16(22):9708-9718
A series of 16 novel thalidomide sulfur analogs containing one and two sulfur atoms 2 and 4-18, respectively, were designed and synthesized. These compounds were screened for in vitro antitumor activity against Ehrlich ascites carcinoma (EAC) cell line and exhibited potent cytotoxic activity. On the bases of the obtained results for in vitro cytotoxic activity, thalidomide sulfur analogs containing two sulfur atoms 8, 9, 13 and 14 were selected and tested in vivo against EAC-induced solid tumor in female mice compared to thalidomide 1 as well as its analog 2 and exhibited a highly significant reduction in tumor volume (TV). Results illustrated the antioxidative activity of these compounds as the level of hepatic lipid peroxidation decreased and levels of antioxidant enzymes like superoxide dismutase (SOD) and catalase were elevated. The histopathological investigations revealed that thalidomide sulfur analogs 2, 8, 9, 13 and 14 have antimitotic, apoptotic and necrotic activities against solid tumor. These compounds lead to increase of Fas-L expression. The immunohistochemical studies showed a decrease in Ki67 and vascular endothelial growth factor (VEGF) staining in tumor cells from treated-animals when compared with non-treated groups, which suggests an inhibition of tumor proliferation rate and angiogenic process associated with tumor growth. Compounds 9 and 13 were the most potent compounds in tumor necrosis without liver necrosis. At the same time, treatment with compound 9 resulted in liver degeneration. 相似文献
5.
Hellwing AL Tauson AH Kjos NP Skrede A 《Animal : an international journal of animal bioscience》2007,1(1):45-54
This experiment investigated the effects of increasing the dietary content of bacterial protein meal (BPM) on the protein and energy metabolism of pigs from weaning to a live weight of 80 kg. Four litters with four castrated male pigs in each litter were used. The litters were divided into two blocks according to age. One pig from each litter was fed one of the four experimental diets. Soya-bean meal was replaced with BPM on the basis of digestible protein, and the BPM contents in the four diets were 0% (BP0), 5% (BP5), 10% (BP10) and 15% (BP15), corresponding to 0%, 17%, 35% and 52% of the digestible nitrogen (N), respectively. Four balance periods were performed, at the start of which the pigs weighed 9.5 kg, 20.7 kg, 45.3 kg and 77.2 kg, respectively. Once during each balance period, 22-h respiration experiments were performed using indirect calorimetry. Daily weight gain, feed intake and feed conversion rate were the same for all diets. The apparent digestibility of N was lower on diet BP10 than on BP0 (P = 0.002), whereas the apparent digestibility of energy was similar on all diets. The retention of nitrogen did not differ between diets and was 1.50, 1.53, 1.33 and 1.46 g N per kg0.75 per day on BP0, BP5, BP10 and BP15, respectively. Neither metabolisable energy intake nor heat production were affected by inclusion level of BPM. Retention of energy was 620 (BP0), 696 (BP5), 613 (BP10) and 664 kJ/kg0.75 per day (BP15), the differences among diets being non-significant. The N-free respiratory quotient was similar on all diets. It was concluded that the overall protein and energy metabolism in growing pigs were not affected when up to 50% of dietary N was derived from BPM. 相似文献
6.
Tagetes minuta is a source of secondary products which are used as pharmaceuticals, pesticides and as flavour components in
the food industry. Cotyledons and hypocotyls of T. minuta were cultured on MS medium with combinations of IAA or NAA and BA.
Hypocotyl-derived callus developed adventitious shoots which failed to develop further. Cotyledon-derived callus, cultured
on medium with IAA, regenerated adventitious shoots which developed into plantlets on MS medium or half-strength MS with 2.85
μM IAA. Cotyledons cultured on medium with 5.71 μM IAA + 44.4 μM BA and transferred to MS medium for shoot growth yielded
the highest number of shoots. Nodal segments from developing shoots were micropropagated on half-strength MS medium with 2.58
μM IAA and 95% of plantlets produced adapted successfully to greenhouse conditions. In vitro plants micropropagated from nodes
had many shoots whereas plants regenerated from shoot tips had only a single main stem. This difference in morphology was
retained after two months growth in a greenhouse. There were no significant differences in leaf and shoot fresh and dry weights
among the regenerated plants after two months growth. After six subcultures of cotyledon-derived callus on medium with IAA
and BA all explants lost their ability to regenerate except those cultured on medium with 17.23 μM IAA and 44.4 μM BA. The
methods of regeneration developed will facilitate selection of T. minuta plants more tolerant of environmental stress, their
micropropagation, and the in vitro production of secondary products.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
7.
8.
A series of mannosyl donors linked via position 2 to an m-xylylene or an isophthaloyl spacer which was connected to the position 6 of a glucoside acceptor afforded, via intramolecular glycosylation, the corresponding disaccharides with high beta anomeric ratio. 相似文献
9.
G. Hallström B. Lindeke A.-H. Khuthier M.A. Al-Iraqi 《Chemico-biological interactions》1981,34(2):185-200
Pargyline undergoes metabolic N-oxidation in rat and rabbit liver microsomal preparations. The reaction requires oxygen and is NADPH dependent. N-oxidation and N-demethylation are equal in both control and induced rat liver microsomes, while N-oxidation is more dominant in rabbit tissue. Experiments investigating the CO-sensitivity and the effects of metyrapone suggest that cytochrome P-450 systems are involved in both reactions in the rat while an additional enzyme is responsible for the N-oxidation in the rabbit. Pargyline N-oxide is characterized by chemical instability and undergoes two consecutive rearrangements to yield propenal and Schiff bases, the latter undergoing hydrolysis to aldehydes and primary amines. Accordingly, due to the inherent instability of the N-oxide, metabolic N-oxidation of pargyline is, in addition to α-carbon oxidation, indicated as a metabolic route to benzaldehyde. Similarly the ease with which pargyline N-oxide generates propenal implicates N-oxidation as a metabolic route to be considered when evaluating the toxicity of pargyline. 相似文献
10.
Blaabjerg K Jørgensen H Tauson AH Poulsen HD 《Animal : an international journal of animal bioscience》2010,4(6):876-885
The aim was to evaluate the effect of heat-treatment, microbial phytase addition and feeding strategy (dry feeding v. fermented liquid feeding) on degradation of phytate (myo-inositol hexakisphosphate, InsP6) and formation and further degradation of lower inositol phosphates (myo-inositol pentakisphosphate-myo-inositol bisphosphate, InsP5-InsP2) at the distal ileum of pigs. Furthermore, the apparent ileal digestibility/degradability (AID) of phosphorus (P), InsP6-P and calcium (Ca) and the apparent total tract digestibility (ATTD) of P and Ca were studied. Pigs were fitted with a T-shaped ileal cannula for total collection of digesta at 2 h intervals during an 8 h sampling period after feeding the morning meal. Each period lasted for 2 weeks: 8 days of adaptation followed by 3 days of total collection of faeces and 3 days of total collection of ileal digesta. The experiment was designed as a 4 × 4 Latin square with four pigs fed four diets. A basal wheat/barley-based diet was fed either as non-heat-treated or heat-treated (steam-pelleted at 90°C). The heat-treatment resulted in an inactivation of plant phytase below detectable level. Diet 1 (non-heat-treated basal diet fed dry); diet 2 (heat-treated basal diet fed dry); diet 3 (as diet 2 but with microbial phytase (750 FTU/kg as fed) fed dry); diet 4 (as diet 3 fed liquid (fermented for 17.5 h nighttime and 6.5 h daytime at 20°C with 50% residue in the tank)). Chromic oxide (Cr2O3) was included as marker and ATTD was determined both by total collection of faeces (ATTDTotal) and Cr2O3 (ATTDCr). InsP6 was completely degraded in diet 4 before feeding resulting in no InsP6-P being present in ileal digesta. InsP6-P concentration in ileal digesta decreased with increasing dietary levels of plant or microbial phytase in pigs fed the dry diets. Consequently, AID and ATTD of P and Ca were greatest for pigs fed diet 4 followed by diets 3, 1 and 2. The ATTD of P depended on the used method as ATTDTotal of P was 72%, 61%, 44% and 34%, whereas ATTDCr of P was 65%, 52%, 38% and 23% for diets 4, 3, 1 and 2, respectively. In all pigs the ileal concentration of InsP5-InsP2-P was extremely small, and thus unimportant for maximisation of ATTD of plant P. In conclusion, fermented liquid feeding with microbial phytase seems to be an efficient approach to improve ATTD of plant P compared with dry feeding. This opens up for further reductions in P excretion. 相似文献