Characterization of equine cytochrome P450: role of CYP3A in the metabolism of diazepam          下载免费PDF全文

S. M. M. Nakayama  Y. Ikenaka  A. Hayami  H. Mizukawa  W. S. Darwish  K. P. Watanabe  Y. K. Kawai  M. Ishizuka 《Journal of veterinary pharmacology and therapeutics》2016,39(5):478-487

Research on drug metabolism and pharmacokinetics in large animal species including the horse is scarce because of the challenges in conducting in vivo studies. The metabolic reactions catalyzed by cytochrome P450s (CYPs) are central to drug pharmacokinetics. This study elucidated the characteristics of equine CYPs using diazepam (DZP) as a model compound as this drug is widely used as an anesthetic and sedative in horses, and is principally metabolized by CYPs. Diazepam metabolic activities were measured in vitro using horse and rat liver microsomes to clarify the species differences in enzyme kinetic parameters of each metabolite (temazepam [TMZ], nordiazepam [NDZ], p‐hydroxydiazepam [p‐OH‐DZP], and oxazepam [OXZ]). In both species microsomes, TMZ was the major metabolite, but the formation rate of p‐OH‐DZP was significantly less in the horse. Inhibition assays with a CYP‐specific inhibitors and antibody suggested that CYP3A was the main enzyme responsible for DZP metabolism in horse. Four recombinant equine CYP3A isoforms expressed in Cos‐7 cells showed that CYP3A96, CYP3A94, and CYP3A89 were important for TMZ formation, whereas CYP3A97 exhibited more limited activity. Phylogenetic analysis suggested diversification of CYP3As in each mammalian order. Further study is needed to elucidate functional characteristics of each equine CYP3A isoform for effective use of diazepam in horses.  相似文献   

Quantifying lignin and holocellulose content in coniferous decayed wood using near-infrared reflectance spectroscopy     

Shigehiro Ishizuka  Yoshimi Sakai  Ayumi Tanaka-Oda 《Journal of Forest Research》2014,19(1):233-237

To determine the independent decomposition rates of lignin and cellulose of decayed woody debris, a technique for the rapid analysis of lignin and cellulose is required. We applied a near-infrared spectroscopy (NIRS) technique to measure the lignin and holocellulose content in decayed wood. We succeeded in creating partial least-squares (PLS) models to estimate the lignin and holocellulose content in the decayed wood of five species using NIR spectra. Although the accuracy was acceptable for the estimation of a five-species mixed model (R ² = 0.970 for lignin and R ² = 0.962 for holocellulose), it was further improved when the model was applied to each species independently. This combination of NIRS and a PLS model is a valuable tool for the determination of the lignin and holocellulose content in decayed wood. The technique is time efficient (3 min per sample) and non-hazardous (no acid treatment is required).  相似文献   

Comparative studies of the quantification of genetically modified organisms in foods processed from maize and soy using trial producing     

Yoshimura T  Kuribara H  Kodama T  Yamata S  Futo S  Watanabe S  Aoki N  Iizuka T  Akiyama H  Maitani T  Naito S  Hino A 《Journal of agricultural and food chemistry》2005,53(6):2060-2069

Seven types of processed foods, namely, cornstarch, cornmeal, corn puffs, corn chips, tofu, soy milk, and boiled beans, were trial produced from 1 and 5% (w/w) genetically modified (GM) mixed raw materials. In this report, insect resistant maize (MON810) and herbicide tolerant soy (Roundup Ready soy, 40-3-2) were used as representatives of GM maize and soy, respectively. Deoxyribonucleic acid (DNA) was extracted from the raw materials and the trial-produced processed food using two types of methods, i.e., the silica membrane method and the anion exchange method. The GM% values of these samples were quantified, and the significant differences between the raw materials and the trial-produced processed foods were statistically confirmed. There were some significant differences in the comparisons of all processed foods. However, our quantitative methods could be applied as a screening assay to tofu and soy milk because the differences in GM% between the trial-produced processed foods and their raw materials were lower than 13 and 23%, respectively. In addition, when quantitating with two primer pairs (SSIIb 3, 114 bp; SSIIb 4, 83 bp for maize and Le1n02, 118 bp; Le1n03, 89 bp for soy), which were targeted within the same taxon specific DNA sequence with different amplicon sizes, the ratios of the copy numbers of the two primer pairs (SSIIb 3/4 and Le1n02/03) decreased with time in a heat-treated processing model using an autoclave. In this report, we suggest that the degradation level of DNA in processed foods could be estimated from these ratios, and the probability of GM quantification could be experimentally predicted from the results of the trial producing.  相似文献   

Cardiovascular effects of tramadol in dogs anesthetized with sevoflurane     

Itami T  Tamaru N  Kawase K  Ishizuka T  Tamura J  Miyoshi K  Umar MA  Inoue H  Yamashita K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(12):1603-1609

Cardiovascular effects of tramadol were evaluated in dogs anesthetized with sevoflurane. Six beagle dogs were anesthetized twice at 7 days interval. The minimum alveolar concentration (MAC) of sevoflurane was earlier determined in each dog. The dogs were then anesthetized with sevoflurane at 1.3 times of predetermined individual MAC and cardiovascular parameters were evaluated before (baseline) and after an intravenous injection of tramadol (4 mg/kg). The administration of tramadol produced a transient and mild increase in arterial blood pressure (ABP) (P=0.004) with prolonged increase in systemic vascular resistance (SVR) (P<0.0001). Compared with baseline value, mean ABP increased significantly at 5 min (119% of baseline value, P=0.003), 10 min (113%, P=0.027), and 15 min (111%, P=0.022). SVR also increased significantly at 5 min (128%, P<0.0001), 10 min (121%, P=0.026), 30 min (114%, P=0.025), 45 min (113%, P=0.025) and 60 min (112%, P=0.048). Plasma concentrations of tramadol were weakly correlated with the percentage changes in mean ABP (r=0.642, P<0.0001) and SVR (r=0.646, P<0.0001). There was no significant change in heart rate, cardiac output, cardiac index, stroke volume, pulmonary arterial pressure, right atrial pressure and pulmonary capillary wedge pressure. In conclusion, the administration of tramadol produces a prolonged peripheral vascular constriction in dogs anesthetized with sevoflurane, which is accompanied with a transient and mild increase in arterial blood pressure. It also indicated that the degree of vasoconstriction might depend on the plasma concentration of tramadol.  相似文献   

Practicable group testing method to evaluate weight/weight GMO content in maize grains     

Mano J  Yanaka Y  Ikezu Y  Onishi M  Futo S  Minegishi Y  Ninomiya K  Yotsuyanagi Y  Spiegelhalter F  Akiyama H  Teshima R  Hino A  Naito S  Koiwa T  Takabatake R  Furui S  Kitta K 《Journal of agricultural and food chemistry》2011,59(13):6856-6863

Because of the increasing use of maize hybrids with genetically modified (GM) stacked events, the established and commonly used bulk sample methods for PCR quantification of GM maize in non-GM maize are prone to overestimate the GM organism (GMO) content, compared to the actual weight/weight percentage of GM maize in the grain sample. As an alternative method, we designed and assessed a group testing strategy in which the GMO content is statistically evaluated based on qualitative analyses of multiple small pools, consisting of 20 maize kernels each. This approach enables the GMO content evaluation on a weight/weight basis, irrespective of the presence of stacked-event kernels. To enhance the method's user-friendliness in routine application, we devised an easy-to-use PCR-based qualitative analytical method comprising a sample preparation step in which 20 maize kernels are ground in a lysis buffer and a subsequent PCR assay in which the lysate is directly used as a DNA template. This method was validated in a multilaboratory collaborative trial.  相似文献   

Nodulation of Rj-soybean varieties with Rhizobium fredii USDA 193 under limited supply of nutrients     

Yoshimasa Nakano  Takeo Yamakawa  Motoki Ikeda  Junji Ishizuka 《Soil Science and Plant Nutrition》2013,59(4):929-932

The compatibility between rhizobia and host plants for nodulation was determined based on the genetic and physiological properties of both symbionts. It has been observed that soybean varieties carrying the Rj-gene were not nodulated effectively by certain strains or groups of rhizobia. Soybeans carrying the Rj ₂-gene, Rj ₂-varieties, were found to nodule ineffectively by the rhizobial strains belonging to the 3-24-44 and 122 serogroups (Caldwell 1966). In the same way, Rj ₃- and Rj ₄-varieties were found to nodule ineffectively by strains USDA 33 (Vest 1970) and USDA 61 (Vest and Caldwell 1972), respectively.  相似文献   

Effects of symbiosis with Rhizobium fredii on transport of fixed nitrogen in the xylem of soybean plants     

Takeo Yamakawa  Teiko Shirai  Junji Ishizuka 《Soil Science and Plant Nutrition》2013,59(4):885-892

An experiment was conducted to identify the main nitrogenous compound transported in the xylem sap of soybean plants nodulated with Rhizobium fredii. Soybean (Glycine max L. Merr.) cultivars, wild type Bragg (nod⁺, fix⁺) and its nitrate tolerant, hypernodulating mutant ntsll16 (nod⁺⁺, fix⁺) were used for this experiment. These soybean plants were inoculated with a slowgrowing rhizobium, Bradyrhizobium japonicum USDAllO or fast-growing rhizobia consisting of a mixture of R. fredii USDA191, USDA193, and USDA-194 and grown in a phytotron under natural light and controlled temperature conditions. Xylem sap was collected from Bragg and ntsll16 plants at the flowering and pod elongation stages. Acetylene reduction activity per plant or per nodule weight was not different between soybean lines and inoculums. The composition of the nitrogenous compounds in the xylem sap was compared between the symbionts, with B. japonicum and R. fredii. At the flowering stage, ureide-N and amide-N accounted for 53 to 70% and 20 to 27% respectively of the total N in the sap collected from the plants inoculated either with B. japonicum or R. fredii. At the pod elongation stage, ureide-N and amide-N accounted for 74 to 85%, and 7 to 19% of total sap N. With the growth of the soybean plants, the ratio of ureide-N in the xylem sap increased. These results suggest that in the case of wild soybean and the hypernodulating mutant line nodulated by R. fredii, ureide is transported as the main nitrogenous compound of fixed nitrogen in the xylem sap in the same way as in plants nodulated with B. japonicum.  相似文献   

Relationship between resistance to bacterial wilt and nutrient uptake in tomato seedlings     

Hiromichi Yamazaki  Osamu Ishizuka  Tsuguo Hoshina 《Soil Science and Plant Nutrition》2013,59(1):203-208

Abstract

Varietal differences in the resistance to bacterial wilt and nutrient uptake of tomato (Lycopersicon esculentum Mill.) seedlings were examined in pot experiments. Twenty-three tomato cultivars were classified into three groups based on the degree of resistance to the disease. Differences in nutrient uptake among cultivars were observed for all the elements tested, and highly resistant cultivars were characterized by a high calcium uptake.  相似文献   

Dietary branched‐chain amino acid supplementation affects growth and hepatic insulin‐like growth factor gene expression in yellowtail,Seriola quinqueradiata          下载免费PDF全文

M. Kawanago  S. Takemura  R. Ishizuka  I. Shioya 《Aquaculture Nutrition》2015,21(1):63-72

We investigated the effect of dietary supplementation with a branched‐chain amino acid (BCAA) mixture (valine, leucine and isoleucine) on juvenile yellowtail (Seriola quinqueradiata) growth and hepatic insulin‐like growth factor (IGF) gene expression. Total dietary BCAA content was 8.1, 8.5, 9.0 and 9.8 g   kg^?1 for the control, 0.4%, 1.0% and 2.0% BCAA experimental groups, respectively. Body weight was measured on day 77, after which fish were fasted for 3 days and refed; the livers were then removed 3 or 9 h later for analysis of hepatic gene expression. Body weight significantly increased in the BCAA‐supplemented groups. Hepatic expression of IGF1 and IGF2 significantly increased in the 2% BCAA group at 3 and 9 h after refeeding. In the 1% BCAA group, hepatic IGF1 expression tended to be higher at 9 h than in the control group after refeeding. Also, hepatic IGF2 significantly increased at only 9 h after refeeding in the 1% BCAA group. In conclusion, dietary supplementation with crystalline BCAAs increased growth and hepatic expression of IGF1 and IGF2. These results suggest that dietary crystalline BCAA supplementation would be a valuable addition to yellowtail aquaculture practices.  相似文献   

Development of a method for forest cafeteria tests for evaluating chemical deterrents against bark stripping by sika deer (Cervus nippon yesoensis)     

Ken Orihashi  Yosuke Yasui  Yasuo Kojima  Minoru Terazawa  Shigehiro Kamoda  Hisatomi Kasahara  Yasuo Takahashi 《Journal of Forest Research》2002,7(1):35-40

Damage caused by sika deer (Cervus nippon yesoensis) is a serious problem in commercial and environmental (non-harvested) forests in Hokkaido, northern Japan. Cafeteria tests in forests may be useful for evaluating the efficacy of chemical deterrents against bark stripping by deer. To develop a method for forest cafeteria tests in the continuous snow cover period, two experiments were carried out. In the experiments, logs were produced from tree trunks, and used as carriers of chemical deterrents. Carriers were installed in forests and fed to deer. The first experiment was to find suitable sites and installation methods for carriers. Criteria for the local suitability and the installation methods were as follows: a) Sites where deer are active should be selected; b) Carriers should be installed along actively used deer trails; c) Installation sites of carriers should be changed in response to deer movement; d) Carriers should be produced from tree species that deer naturally prefer; and e) Each carrier should be partially buried in the snow. The second experiment evaluated the feasibility of a cafeteria test method based on the results of the first experiment. The method was used for 13 sets of the cafeteria test, in which the deterrent effectiveness of 5 chemicals (wood tar, rosin, wood vinegar, and 2 pyroligneous liquors) was examined. We obtained results from all the sets. The chemicals tested did not deter bark stripping by deer. Nevertheless, the method used in the present study was practical for the cafeteria tests.  相似文献