Metabolism of14C-labeled epibrassinolide in intact seedlings of cucumber and wheat

The metabolism of exogenously applied¹⁴C-24-epibrassinolide (¹⁴C-EBR) in seedlings of cucumber and wheat was examined. Total lipids were extracted with isopropanol and chloroform, and then partitioned with water. More than 80% of radioactivity was distributed to chloroform-phase. Concentrated chloroform-phase was applied to silica gel plate and was developed with chloroform-ethanol (5:1 v/v). Rf value of original¹⁴C-EBR was about 0.6. In cucumber leaves harvested after 2 day-culture, three peaks were detected at Rf 0.11, 0.47 and 0.84. In cucumber petioles of 2 day-culture, however, a major peak was detected at Rf 0.90. But¹⁴C-EBR was hardly metabolized in hypocotyls and roots after 2 days. In wheat leaves harvested just after pulse labeling, a peak was detected at Rf 0.63. By further analysis of this peak using ODS-HPLC, however, an original peak of¹⁴C-EBR and two metabolites having higher polarity were detected. In wheat leaves harvested after 2 day-culture, the profile of TLC scanning was similar to that just after pulse labeling, although, an original peak of¹⁴C-EBR was no longer detected by ODS-HPLC. In wheat roots,¹⁴C-EBR was hardly metabolized. These results indicate that¹⁴C-EBR occurring in leaves and petioles is metabolized to produce several kinds of metabolites.     

14C2H4: Distribution of 14C-labeled tissue metabolites in pea seedlings

The ¹⁴C-metabolite distribution pattern following ¹⁴C₂H₄ metabolismin intact pea seedlings (Pisum sativum L.) was determined undervarious conditions. After a 24 hr exposure to ¹⁴C₂H₄, the majorityof ¹⁴C-metabolites were water-soluble (60–70%) with lesseramounts in the protein (10–15%), lipid (1%), and insoluble(1–2%) fractions. Ion exchange chromatography of the water-solublecomponents into basic, neutral, and acidic fractions revealeda 50 : 40 : 10 distribution, respectively. Chromatography ofthe neutral fraction revealed two regions of radioactivity (Rf=0.38)and 0.63 which did not cochromatograph with twenty-two knownsugars or neutral metabolites. Chromatograms of the basic fractioncontained 3 regions of radioactivity. Similar distribution patternswere noted when ¹⁴C₂H₄ exposure was followed by a 6 hr air chaseor when 5% CO₂, an antagonist of ethylene action, was presentduring the exposure. Marked differences in the ¹⁴C-metabolite distribution patternswere obtained when ¹⁴CO₂ was substituted for ¹⁴C₂H₄. These resultsindicate that the metabolic pathway involved in ethylene metabolismis different from that involved in intermediary carbon metabolism. ¹ Contribution No. 2338 from Central Research and DevelopmentDepartment, Experimental Station, E. I. du Pont de Nemours andCompany, Wilmington, Delaware. (Received June 28, 1976; )     

The uptake and the transport of14C-labeled epibrassinolide in intact seedlings of cucumber and wheat

The uptake and the transport of exogenously applied epibrassinolide (EBR) in seedlings of cucumber and wheat were examined by autoradiography using¹⁴C-EBR.¹⁴C-EBR was applied to roots, young and mature leaves, and the shoot apex. When applied to roots,¹⁴C-EBR was readily taken up and was swiftly transported throughout both plant species. When¹⁴C-EBR was applied to the adaxial surface of a young cucumber leaf, it was readily taken up, but was very slowly transported. In cucumber leaves,¹⁴C-EBR was transported throughout the treated leaf after 3 days of treatment, and then it was transported to upper leaves from the treated leaf after 7 days. Some 6.3% of applied¹⁴C-EBR was transported to the newly expanded leaves. In wheat leaves,¹⁴C-EBR was transported only in the apical direction from the treated spot after 3 days of treatment, but it was not transported from the treated leaf to the other leaves or organs even after 7 days. Some 1.3% of applied¹⁴C-EBR was transported to the tip area of the treated leaf. These results indicate that exogenous EBR applied to intact plants is acropetally transported.     

Energy intake in late gestation affects blood metabolites in early lactation independently of milk production in dairy cows

The present experiment examined the effect of offering either a high- (H) or low- (L) energy-density diet in late gestation and early lactation on physiological parameters, body condition score (BCS) and milk production in early lactation. In all, 40 multiparous Holstein cows were randomly allocated to one of four treatments in a 2 × 2 factorial design, where the factors were H- or L-energy density in a total mixed ration (TMR) both pre- and post-calving. Consequently, there were four treatment groups: HH, HL, LL and LH. The pre-calving treatment was initiated 100 days prior to expected calving; the H TMR was fed ad libitum whereas the L TMR was restricted to 10 kg dry matter/day during late lactation, and to approximately 75% of energy requirements from drying off until calving. Both diets were offered ad libitum post-calving. Feeding diet H compared to L pre-calving led to higher BCS at calving (2.68 v. 2.34, P < 0.01). Energy corrected milk yield and energy-intake post-calving were not affected by pre-calving diets. Changes in BCS and blood concentrations of non-esterified fatty acids, beta-hydroxybutyrate and glucose in early lactation showed that cows offered diet H pre-calving generally mobilised more body reserves compared to cows offered diet L pre-calving. An interaction between pre- and post-calving diets showed that cows offered diet H pre-calving had lower body tissue mobilisation when offered diet H post-calving compared to diet L. Cows offered diet L pre-calving, did not mobilise differently whether they were offered diet H or L post-calving. The pre- and post-calving diets had no effect on liver triacylglycerol, whereas liver glycogen was higher in cows on treatment HH compared to the other three treatments. Collectively, these results indicate that overfeeding should be avoided in late gestation and that a high-energy-density diet is desirable in early lactation in order to obtain a more favourable metabolic profile.     

Selenium concentration in blood and hair of holstein dairy cows

Four-hundred Holstein cows in 40 dairy farms in north Greece were included in this study, and blood (n=400), black hair (n=400), white hair (n=40), and feed (n=40) samples were obtained. Although the feeding regime in these farms was similar, the selenium content of feeds was variable. The Se content of concentrate feeds was 0.104±0.086 mg/kg dry matter (DM), and of silage, it was 0.025±0.018 mg/kg. A significantly positive correlation was found between the Se concentration in black hair and the Se concentration in blood (r ²=0.610, p<0.001), the Se concentration in white hair and the Se concentration in blood (r ²=0.770, p<0.001), and the Se concentration in white hair and the Se concentration in black hair (r ²=0.921, p<0.001). The Se concentration in white hair was significantly smaller than that in black hair (p<0.001).     

The biosynthetic pathway of curcuminoid in turmeric (Curcuma longa) as revealed by 13C-labeled precursors

In order to investigate the biosynthesis of curcuminoid in rhizomes of turmeric (Curcuma longa), we established an in vitro culture system of turmeric plants for feeding (13)C-labeled precursors. Analyses of labeled desmethoxycurcumin (DMC), an unsymmetrical curcuminoid, by (13)C-NMR, revealed that one molecule of acetic acid or malonic acid and two molecules of phenylalanine or phenylpropanoids, but not tyrosine, were incorporated into DMC. The incorporation efficiencies of the same precursors into DMC and curcumin were similar, and were in the order malonic acid > acetic acid, and cinnamic acid > p-coumaric acid > ferulic acid. These results suggest the possibility that the pathway to curcuminoids utilized two cinnamoyl CoAs and one malonyl CoA, and that hydroxy- and methoxy-functional groups on the aromatic rings were introduced after the formation of the curcuminoid skeleton.     

The lactose synthetase particles of lactating bovine mammary gland. Preparation of particles with intact lactose synthetase

1. The particulate form of lactating bovine mammary lactose synthetase activity is shown to be more highly organized than previously reported. 2. A novel method of shattering frozen mammary tissue with effective cell disruption is described. 3. The apparent subcellular distribution of lactose synthetase was shown to reflect the method of homogenization. 4. After mild homogenization particles associated with a high content of intact lactose synthetase activity sedimented in the lysosome size range between 5×10⁴ and 3×10⁵g-min. 5. Lactose synthetase was dissociated and solubilized by VirTis homogenization and ultrasonic treatment. The activities and behaviour of UDP-galactose hydrolase, succinate dehydrogenase, β-glucuronidase and phosphodiesterase I were compared. 6. Inhibition of UDP-galactose hydrolase by UTP and α-lactalbumin was observed.     

The metabolism of radium in dairy cows

1. The isotopes (45)Ca and (224)Ra were administered simultaneously, both orally and intravenously, to two pairs of cows. 2. The first pair of animals received large doses of (224)Ra and (45)Ca, which produced clinical and metabolic disturbances. 3. The second pair of animals received much smaller doses and showed no clinical disturbances. The mean recoveries in these animals of (45)Ca and (224)Ra in the 8 days after the oral administration were respectively: from faeces, 63.2 and 103.8%; from urine, 0.26 and 0.44%; from milk, 15.8 and 0.35% of the dose; and in the 8 days after intravenous administration: from faeces, 20.5 and 36.5%; from urine, 1.56 and 17.6%; from milk, 49.3 and 11.8% of the dose. 4. Calculation of discrimination factors shows that absorptive discrimination played the most important part in the overall discrimination between the calcium and radium in their passage from diet to milk, but that mammary discrimination plays a more important role than in the overall discrimination between calcium and strontium or barium. 5. In its treatment by the kidney radium is more like strontium than barium, but radium is actively secreted by the gut in the same way as barium. 6. In its skeletal metabolism radium is indistinguishable from calcium and strontium except in its rate of resorption, which is similar to that of barium.     

热应激奶牛外周血淋巴细胞凋亡相关基因表达及血液学分析

用半定量RT- PCR分析日平均气温分别为37 .5°C (高温)、26. 5°C (临界高温) 和5 5°C (对照) 条件下奶牛外周血中HSP70mRNA、HSF1mRNA、Bcl 2mRNA和Bax αmRNA 基因丰度变化规律; 用流式细胞仪分析上述条件下外周血淋巴细胞所处的分裂时期(G0/G1 期, S期及G2/M期) 及淋巴细胞的凋亡率; 用全血自动分析仪分析外周血的血常规。研究发现: (1) 在37. 5°C高温条件下, HSP70mRNA 基因表达水平极显著高于26 .5°C和5 5°C条件下的表达量, 表达水平随温度降低呈下降趋势; HSF1mRNA 表达水平与HSP70mRNA 相反, 随温度降低升高, 5 5°C最高, 相对于其它两个温度条件差异显著; Bcl 2mRNA/Bax αmRNA 在26 5°C时最低, 相对于其它两个温度条件该基因的丰度差异显著; (2) 淋巴细胞凋亡率在26 5°C达到最高峰(10 60%),5 5°C下降至最低(2 7%), 差异显著; (3) 白细胞计数(White blood cell, WBC) (14 75×109/L) 和红细胞计数(Red blood cell, RBC) ( 3 .85×1012/L) 在高温37. 5°C时最低, 随温度下降而逐步上升。RBC 和血红蛋白(Hemoglobin, HGB) 在37. 5°C最低, 随温度降低逐步升高, 相对于其它两个温度差异显著; 红细胞平均血红蛋白含量(Mean corpuscular hemoglobin, MCH) 在26. 5°C最高(18 .8     

Low cortisol levels in blood from dairy cows with ketosis: a field study

Background  

An elevated plasma glucose concentration has been considered to be a potential risk factor in the pathogenesis of left-displaced abomasums (DA). Therefore the present study was performed to investigate if spontaneous disease (parturient paresis, metritis, ketosis etc) in dairy cows results in elevated concentrations of glucose and cortisol in blood as cortisol is the major regulator of glucose in ruminants.     

14C-labeled metabolites in heterocysts and vegetative cells of Anabaena cylindrica filaments and their presumptive function as transport vehicles of organic carbon and nitrogen

To investigate the transport of primary metabolites in Anabaena cylindrica from vegetative cells into heterocysts, intact filaments were labeled with the heterocysts were separated from the vegetative cells after different time intervals, and the labeling patterns were determined. After a 20-s fixation time, a high percentage of labeling of alanine, glutamate and glutamine, and, to a lesser extent, glucose 6-phosphate was found in heterocysts as compared with whole filaments. The results can be explained if transport of alanine, glutamate, and sugars from vegetative cells into heterocysts is assumed. Alanine can serve as a precursor for reducing equivalents if it is oxidized to glutamine which flows back to the vegetative cells. This idea is supported by an experiment in which exogenous alanine is readily converted by isolated heterocysts to glutamate and glutamine under a N2-H2 atmosphere. The incorporation of [14C]carbonate in isolated heterocysts demonstrated the absence of the reductive pentose phosphate pathway; however, it revealed marked activity of an acid fixation reaction.     

Relationships between methane emission of Holstein Friesian dairy cows and fatty acids,volatile metabolites and non-volatile metabolites in milk

This study investigated the relationships between methane (CH₄) emission and fatty acids, volatile metabolites (V) and non-volatile metabolites (NV) in milk of dairy cows. Data from an experiment with 32 multiparous dairy cows and four diets were used. All diets had a roughage : concentrate ratio of 80 : 20 based on dry matter (DM). Roughage consisted of either 1000 g/kg DM grass silage (GS), 1000 g/kg DM maize silage (MS), or a mixture of both silages (667 g/kg DM GS and 333 g/kg DM MS; 333 g/kg DM GS and 677 g/kg DM MS). Methane emission was measured in climate respiration chambers and expressed as production (g/day), yield (g/kg dry matter intake; DMI) and intensity (g/kg fat- and protein-corrected milk; FPCM). Milk was sampled during the same days and analysed for fatty acids by gas chromatography, for V by gas chromatography–mass spectrometry, and for NV by nuclear magnetic resonance. Several models were obtained using a stepwise selection of (1) milk fatty acids (MFA), V or NV alone, and (2) the combination of MFA, V and NV, based on the minimum Akaike’s information criterion statistic. Dry matter intake was 16.8±1.23 kg/day, FPCM yield was 25.0±3.14 kg/day, CH₄ production was 406±37.0 g/day, CH₄ yield was 24.1±1.87 g/kg DMI and CH₄ intensity was 16.4±1.91 g/kg FPCM. The observed CH₄ emissions were compared with the CH₄ emissions predicted by the obtained models, based on concordance correlation coefficient (CCC) analysis. The best models with MFA alone predicted CH₄ production, yield and intensity with a CCC of 0.80, 0.71 and 0.69, respectively. The best models combining the three types of metabolites included MFA and NV for CH₄ production and CH₄ yield, whereas for CH₄ intensity MFA, NV and V were all included. These models predicted CH₄ production, yield and intensity better with a higher CCC of 0.92, 0.78 and 0.93, respectively, and with increased accuracy (C_b) and precision (r). The results indicate that MFA alone have moderate to good potential to estimate CH₄ emission, and furthermore that including V (CH₄ intensity only) and NV increases the CH₄ emission prediction potential. This holds particularly for the prediction model for CH₄ intensity.     

Relationships between thyroid hormones and serum energy metabolites with different patterns of postpartum luteal activity in high-producing dairy cows

This study investigated the relationships of thyroid hormones, serum energy metabolites, reproductive parameters, milk yield and body condition score with the different patterns of postpartum luteal activity in the postpartum period. A total of 75 multiparous healthy (free of detectable reproductive disorders) Holstein dairy cows (mean peak milk yield = 56.5 ± 7.0 kg/day) were used in this study. Transrectal ultrasound scanning and blood sample collection were performed twice weekly. Serum concentrations of progesterone (P₄) were measured twice weekly and beta-hydroxybutyrate (BHBA), non-esterified fatty acids, thyroxine (T₄), 3,30,5-tri-iodothyronine (T₃), free thyroxine (fT₄) and free 3,30,5-tri-iodothyronine (fT₃) were measured every 2 weeks from the 1st to the 8th week postpartum. On the basis of the serum P₄ profile of the cows, 25 (33.4%) had normal luteal activity (NLA), whereas 30 (40%), 10 (13.3%), 6 (8%) and 4 (5.3%) had prolonged luteal phase (PLP), delayed first ovulation (DOV), anovulation (AOV) and short luteal phase, respectively. Serum T₄ concentrations in PLP cows were higher than that in NLA cows at the 3rd week postpartum and did not change during the period of study, whereas in the NLA cows the concentrations increased (P < 0.05). Further, the least square (LS) mean of serum fT₄ concentrations in the DOV and AOV cows were significantly lower than in the NLA cows during the study period (P < 0.05). In addition, the AOV cows had higher LS mean serum BHBA and T₄ concentrations than the NLA cows in early weeks postpartum (P < 0.05). In conclusion, the serum thyroid hormones’ profile differs in high-producing dairy cows showing PLP, AOV and DOV in comparison with the postpartum NLA cows.