Effects of bovine cytochrome P450 single-nucleotide polymorphism, forage type and body condition on production traits in cattle

Relating single-nucleotide polymorphisms (SNP) to cows with acceptable productivity could benefit cattle breeders in areas where tall fescue is the predominant forage. This study aimed to (i) identify SNPs in bovine cytochrome P450 3A28 (CYP3A28) and (ii) determine the associations between SNP genotype, forage and cow body condition (BC). Genotype (CC, CG or GG) and forage [Kentucky-31 wild-type endophyte-infected tall fescue (KY+) vs. bermudagrass] effects on milk volume and quality were determined in Herd 1 cows (123 cows); in Herd 2 (99 cows), genotype and BC (low vs. moderate) effects on ovarian follicle size, calving date and calving per cent were determined; and in Herd 3 (114 cows), effects of genotype and fescue cultivar [KY+ vs. non-toxic endophyte-infected tall fescue (HiMag4)] were related to calving per cent, calving date and weaning weights of both cow and her calf. A cytosine (C) to guanine (G) transversion at base 994 (C994G) in CYP3A28 was identified. There was a genotype × forage type interaction (p < 0.05) on milk protein in Herd 1 cows; CC cows grazing bermudagrass had greater milk protein percentage in relation to other cows in the herd. In Herd 2, BC and genotype × BC tended (p < 0.10) to influence follicle size and Julian calving date respectively. Diameter of the largest follicle tended to be larger in moderate BC than in low-BC cows; whereas, CC and CG cows in moderate BC and homozygous (CC and GG) cows in low BC tended to calve 14 days earlier in relation to CG cows in low BC. In Herd 3, there was a genotype × forage type interaction (p < 0.05) on calving per cent, Julian calving date and calf weaning weight. In this study, genetic alterations (G allele at C994G) coupled with nutritional factors (low BC and toxic tall fescue) resulted in overall lower productivity in cows.     

Effects of dapagliflozin in combination with insulin on cytochrome P450 activities in a diabetes type 1 rat model

Previous studies reported that diabetes alters the activities of hepatic cytochrome P450 (CYP) enzymes, which, in turn, affects the disposition of some drugs. We herein examined and compared the effects of the combination of dapagliflozin with a low insulin dose, a full dose of insulin alone, and dapagliflozin alone for 3 and 8 weeks on CYP activities in a diabetes type 1 rat model. We induced type 1 diabetes in rats using a single intraperitoneal injection of 60 mg/kg streptozotocin (STZ). Daily treatment with the full dose of insulin alone, dapagliflozin alone, or dapagliflozin in combination with a low dose of insulin was then initiated. STZ-induced rats developed marked hyperglycemia and altered CYP2E activities. Dapagliflozin in combination with a low dose of insulin stabilized hyperglycemia and CYP1A, 2D, 2E and 3A activities. However, dapagliflozin alone did not improve blood glucose levels or CYP activities. These results suggest that the effects of dapagliflozin in combination with a low dose of insulin are similar to those of a full dose of insulin, and stabilize CYP activities in type 1 diabetes.     

Flunixin对猪肝微粒体细胞色素P450酶系的影响

采用cocktail探针药物法研究了氟尼辛葡甲铵对猪肝微粒体细胞色素（CY）P450酶系的作用.将12头猪随机分为2组,试验组每日肌肉注射氟尼辛葡甲铵1次,对照组给予等体积的生理盐水,连续给药10 d.通过高效液相色谱法检测探针药物的代谢率,评价各组CYP450酶的活性水平.结果显示,试验组的氨苯砜代谢减慢,消除半衰期t1/2延长;而氯唑沙宗代谢加快,t1/2缩短.说明氟尼辛葡甲铵对猪的CYP3A4具有抑制作用,而对CYP2E1存在诱导效应.     

Identification of the putative ancestral allele of bovine single‐nucleotide polymorphisms

Identifying the action of natural selection from patterns of standing genetic variation has long been of interest to the population genetic community. Thanks to the availability of large single‐nucleotide polymorphism (SNP) data sets for many species and of high‐throughput SNP genotyping methods, whole‐genomic surveys to detect selective sweeps are now possible. Knowing the ancestral allele increases the power to detect selection. We present here a comparative genomic approach to determine the putative ancestral allele of bovine SNPs deposited in public databases. We analysed 19 551 488 SNPs and identified the putative ancestral allele for 14 339 107 SNPs. Our predicted ancestral alleles were in agreement with ancestral alleles detected by genotyping outgroup species for 97% SNPs from the BovineSNP50 BeadChip. This comparison indicates that our comparative genomic‐based approach to identify putative ancestral alleles is reliable.     

几种临床常用药物对猪肝细胞色素P450酶系的影响

研究了几种临床常用药物对猪肝微粒体细胞色素P450酶系的影响。红霉素、环丙沙星、地塞米松和乙醇,按5倍治疗剂量进行肌肉注射每天1次,连续给药10 d。差速离心法制备猪肝微粒体,B radford法测定蛋白浓度,分光光度法检测6种肝细胞色素P450酶含量及活性。结果表明,4种药物除环丙沙星外,均对P450酶的总活性产生显著影响(P<0.05),同时地塞米松组的微粒体蛋白含量和红霉素-N-脱甲基酶活性,乙醇组的苯胺-4-羟化酶活性和红霉素组的红霉素-N-脱甲基酶活性,与对照组相比均差异显著(P<0.05)。说明环丙沙星和红霉素对猪肝细胞色素P450酶系有选择性抑制作用,而地塞米松和乙醇对其起选择性诱导作用。     

Characteristics of cytochrome P450-dependent metabolism in the liver of the wild raccoon,Procyon lotor

Wildlife is exposed to a wide range of xenobiotics in the natural environment. In order to appropriately assess xenobiotic-induced toxicity in wildlife, it is necessary to understand metabolic capacities. Carnivores, in general, have low metabolic abilities, making them vulnerable to a variety of chemicals. Raccoons (Procyon lotor) in the wild have been found to have high levels of xenobiotics. However, little is known about the metabolic capacity of the cytochrome P450 (CYP) enzymes in this species. Thus, this study used liver samples to investigate the characteristics of CYP enzymes in wild raccoons. In 22 wild raccoons, CYP concentrations in hepatic microsomes were examined. To better understand the properties of CYP-dependent metabolism, in vitro metabolic activity studies were performed using ethoxyresorufin, pentoxyresorufin and testosterone as substrates. In addition, three raccoons were fed commercial dog food in the laboratory for one week, and the effects on CYP-dependent metabolism were investigated. In comparison to other mammalian species, raccoons had very low concentrations of CYP in their livers. In an in vitro enzymatic analysis, raccoons’ ethoxyresorufin O-deethylase (EROD) and pentoxyresorufin O-depentylase (PROD) metabolic capacities were less than one-fifth and one-tenth of rats’, respectively. These results indicate the possible high risk in raccoons if exposed to high levels of environmental xenobiotics because of their poor CYP activity. In this study, the features of CYP-dependent metabolism in wild raccoons are described for the first time.     

乐果亚急性暴露对大鼠胆碱酯酶浓度及细胞色素P450亚型表达量的影响

对6周龄雄性Wistar大鼠5次灌胃给予20％LD50的乐果，观察给药后大鼠的毒性反应，每日测定实验鼠采食量、饮水量和体重。最后一次给药后第24h，采用丁酰硫代胆碱法测定大鼠红细胞、血清和脑组织中的胆碱酯酶浓度，并采用定量RT-PCR法检测大鼠肝中细胞色素P450基因8个亚型的表达量。结果表明，大鼠用药后不同时间内出现了有机磷药物中毒的典型症状，其采食量、饮水量和体重明显下降，红细胞、血清和脑组织中胆碱酯酶浓度均明显低于对照组，肝细胞色素P450的8个亚型中CYP2B1／2的表达量明显高于对照组。     

Effects of body condition score (BCS) on steroid‐ and eicosanoid‐metabolizing enzyme activity in various mare tissues during winter anoestrus

The objective of this study was to determine the activity of steroid‐ and eicosanoid‐metabolizing enzymes in horses with varying BCSs. The BCSs of twenty non‐pregnant, anoestrous mares were determined prior to euthanasia, and tissue samples were collected from the liver, kidney, adrenal gland, ovary and endometrium. Cytochrome P450 1A (CYP1A), 2C (CYP2C), 3A (CYP3A) and uridine 5′‐diphospho‐glucuronosyltransferase (UGT) activities were determined using luminogenic substrates. The MIXED procedure of SAS was used to test the effect of BCS on enzyme activity and differences between tissues. Activity of CYP1A in adrenals was increased (p ≤ .05) in BCS 5 versus BCSs 4 and 6. Activity of CYP1A in the liver was increased (p = .05) in BCS 4 versus BCSs 5 and 6. Activity of CYP1A was 100‐fold greater (p < .0001) in the liver than in the adrenal, ovary and kidney. Activity of CYP2C was 100‐fold greater (p < .0001) in the liver than in the adrenal, ovary and endometrium. Activity of CYP3A was only detectable in the liver. Activity of UGT in the kidney was decreased (p = .02) in BCS 4 versus BCSs 5 and 6. Activity of UGT was threefold greater (p < .0001) in the liver than in the kidney, whereas activity of UGT was ninefold greater (p < .0001) in the kidney than in the ovary and endometrium. In general, BCS did not alter the activity of steroid‐ and eicosanoid‐metabolizing enzymes in horses. However, tissue differences in these enzymes indicated abundant hepatic metabolism in horses, which is similar to other livestock species.     

Effect of cytochrome P450 inhibition on toxicity of diclofenac in chickens: Unravelling toxicity in Gyps vultures

Diclofenac was responsible for the decimation of Gyps vulture species on the Indian subcontinent during the 1980s and 1990s. Gyps vultures are extremely sensitive (the lethal dose 50 [LD_50] ~ 0.1 mg/kg – 0.2 mg/kg), with toxicity appearing to be linked to metabolic deficiency, demonstrated by the long T_1/2 (~12 h – 17 h). This is in striking comparison to the domestic chicken (Gallus gallus domesticus), in which the LD₅₀ is ~10 mg/kg and the T_1/2 is ~1 h. The phase 1 cytochrome P450 (CYP) 2C subfamily has been cited as a possible reason for metabolic deficiency. The aim of this study was to determine if CYP2C9 homolog pharmacogenomic differences amongst avian species is driving diclofenac toxicity in Gyps vultures. We exposed each of 10 CYP-inhibited test group chickens to a unique dose of diclofenac (as per the Organisation for Economic Co-operation and Development [OECD] toxicity testing guidelines) and compared the toxicity and pharmacokinetic results to control group birds that received no CYP inhibitor. Although no differences were noted in the LD₅₀ values for each group (11.92 mg/kg in the CYP-inhibited test group and 11.58 mg/kg in the control group), the pharmacokinetic profile of the test group was suggestive of partial inhibition of CYP metabolism. Evaluation of the metabolite peaks produced also suggested partial metabolic inhibition in test group birds, as they produced lower amounts of metabolites for one of the three peaks demonstrated and had higher diclofenac exposure. This pilot study supports the hypothesis that CYP metabolism is varied amongst bird species and may explain the higher resilience to diclofenac in the chicken versus vultures.     

Identification and characterization of the enzymes responsible for the metabolism of the non‐steroidal anti‐inflammatory drugs,flunixin meglumine and phenylbutazone,in horses

The in vivo metabolism and pharmacokinetics of flunixin meglumine and phenylbutazone have been extensively characterized; however, there are no published reports describing the in vitro metabolism, specifically the enzymes responsible for the biotransformation of these compounds in horses. Due to their widespread use and, therefore, increased potential for drug–drug interactions and widespread differences in drug disposition, this study aims to build on the limited current knowledge regarding P450‐mediated metabolism in horses. Drugs were incubated with equine liver microsomes and a panel of recombinant equine P450s. Incubation of phenylbutazone in microsomes generated oxyphenbutazone and gamma‐hydroxy phenylbutazone. Microsomal incubations with flunixin meglumine generated 5‐OH flunixin, with a kinetic profile suggestive of substrate inhibition. In recombinant P450 assays, equine CYP3A97 was the only enzyme capable of generating oxyphenbutazone while several members of the equine CYP3A family and CYP1A1 were capable of catalyzing the biotransformation of flunixin to 5‐OH flunixin. Flunixin meglumine metabolism by CYP1A1 and CYP3A93 showed a profile characteristic of biphasic kinetics, suggesting two substrate binding sites. The current study identifies specific enzymes responsible for the metabolism of two NSAIDs in horses and provides the basis for future study of drug–drug interactions and identification of reasons for varying pharmacokinetics between horses.     

大豆黄酮对伊莎鸡卵泡发育及其P450arom基因表达的影响

实验探讨了大豆黄酮(DAI)对伊莎鸡卵泡发育及其芳香化酶(P450arom)mRNA表达的影响。实验选取16只产蛋后期伊莎鸡,等分为对照组和DAI处理组。对照组饲喂基础日粮,实验组在基础日粮中添加10 mg/kgDAI。实验持续7周后,分离排卵前卵泡(F1、F2、F3……)的颗粒层及小黄卵泡和大白卵泡,通过RT-PCR法检测P450arom mRNA表达的相对丰度。结果表明:DAI明显提高了伊莎鸡小黄卵泡和大白卵泡的数量,P450arommRNA在伊莎鸡不同发育阶段卵泡中的表达存在差异,部分卵泡P450arom mRNA表达的相对丰度显著增加。因此,在产蛋后期伊莎鸡基础日粮中添加DAI可增加不同发育阶段卵泡的数目,上调部分卵泡中与发育相关的基因表达以促进卵泡发育。     

Genotypes and allele frequencies of buried SNPs in a bovine single‐nucleotide polymorphism array in Japanese Black cattle

Single nucleotide polymorphism (SNP) arrays are widely used for genetic and genomic analyses in cattle breeding; thus, data derived from SNP arrays have accumulated on a large scale nationwide. Commercial SNP arrays contain a considerable number of unassigned SNPs on the chromosome/position on the genome; these SNPs are excluded in subsequent analyses. Notably, the position‐unassigned SNPs, or “buried SNPs” include some of the markers associated with genetic disease. In this study, we identified the position of buried SNPs using the Basic Local Alignment Search Tool against the surrounding sequences and characterized the relationship between SNPs and genetic diseases in Online Mendelian Inheritance in Animals based on the genomic position. We determined the position of 285 buried SNPs on the genome and surveyed the genotype and allele frequencies of these SNPs in 5,955 individual Japanese Black cattle. Eleven SNPs associated with genetic disease, which contained five buried SNPs, were found in the population with the risk allele frequency ranging from 0.00008396 to 0.46. These results indicate that buried SNPs in the bovine SNP array can be utilized to identify associations with genetic disorders from large scale accumulated SNP genotype data in Japanese Black cattle.     

泌乳期母猪的饲喂频率对其体况、生产和繁殖性能的影响

文章评估了哺乳期间母猪的饲喂频率(2或3次/d)对母猪体况、繁殖性能及仔猪生长性能的影响。试验选择68头母猪,随机分为8组(每组8~10头母猪),哺乳期间其中4组母猪每天饲喂2次,另外4组每天饲喂3次,母猪分为青年母猪(<2胎次)和老龄母猪(≥3胎次),试验结束后记录母猪体况评分、肩部组织病变、发情率、母猪生产及仔猪生长性能。结果显示:每天饲喂3次的母猪比饲喂2次的母猪采食量高(P<0.05),肩部组织病变低(P<0.05)。在每天饲喂3次的母猪中,青年母猪返情率为0%,老龄母猪返情率为29%,而在每天饲喂2次的母猪中,青年母猪发情率为20%,老龄母猪为5%。综上所述,在哺乳期,母猪每天饲喂3次较每天饲喂2次提高了采食量,对母猪体况评分和肩部组织病变有改善作用,同时也降低了年轻母猪的返情率。     

Assessment of body fat in the pony: part I. Relationships between the anatomical distribution of adipose tissue, body composition and body condition

Reasons for performing study: Evaluation of equine body fat content is important for nutritional and clinical purposes. However, our understanding of total body fat and its regional distribution in the body is sparse. Currently, body fat evaluation relies on the subjective assessment of body condition score (BCS), which has never been validated against ‘gold standard’ chemical analysis or dissection measurements in ponies. Objectives: To define the relationships between subjective (BCS), objective (morphometric) indices of body fat and ‘gold standard’ measurements of actual body composition. Hypotheses: BCS and morphometry offer valid, noninvasive methods for determination of body fat in equids. Methods: Seven mature (mean ± s.e. 13 ± 3 years, 212 ± 14 kg, BCS 1.25–7/9), Welsh Mountain pony mares, destined for euthanasia (for nonresearch purposes), were used. For all ponies, body mass (BM), BCS and various morphometric measurements were recorded. Following euthanasia, all ponies were systematically dissected. Discrete white adipose tissue (WAT) depots were independently described. Gross, body chemical composition was determined by proximate analyses. Results: Total somatic soft tissues increased linearly (r²= 1.00), whereas body WAT content (1–26% live BM) increased exponentially (r²= 0.96), with BCS. WAT was equally distributed between internal and external sites in all animals irrespective of BCS. Nuchal fat was a poor predictor of total WAT (r²= 0.66). Periorbital WAT did not alter with BCS (r²= 0.01). Heart girth:withers height and ultrasonic retroperitoneal fat depth were closely associated with total, chemically‐extracted lipid which comprised 1–29% live BM (r²= 0.91 and 0.88, respectively). Conclusions and potential relevance: The exponential relationship between BCS and total body WAT/lipid suggests that BCS is unlikely to be a sensitive index of body fat for animals in moderate‐obese states. Morphometric measurements (body girths and retroperitonel fat depth) may be useful to augment subjective BCS systems.     

The regulatory effect of genistein on P450 aromatase and follicle-stimulating hormone receptor in mouse experimental model of menopausal metabolic syndrome

In order to investigate the mechanism of genistein (Gen) in the treatment of climacteric syndrome, an in vivo study was performed to investigate the beneficial effects of genistein on the expression of P450 aromatase (P450 arom) and follicle-stimulating hormone receptor (FSHR) in the mouse ovary and uterus. Fifty female ICR mice (45 ± 5g, n = 50), aged 12 months, were divided into the following five groups with 10 animals in each: blank control group (CG), low-dose genistein group (L-Gen), middle-dose genistein group (M-Gen) and high-dose genistein group (H-Gen) (received 15, 30 and 60 mg/kg of genistein, respectively), and oestrogen group (EG; received 0.5 mg/kg diethylstilbestrol). The expression levels of the FSHR protein were determined by an immunohistochemical staining method. The expression of P450 arom, Cytochrome P450 19 (CYP19) and FSHR was quantified by real-time PCR. Immunohistochemical results showed that the expression levels of the FSHR protein in the M-Gen (average stained area: 20.79) and the H-Gen (average stained area: 21.21) groups were significantly stronger than in the CG (average area was 17.24) group (p < .05). The expression levels of CYP19 mRNA and P450 arom were positively correlated with the dose of genistein. Specifically, the relative expression levels in the H-Gen and EG groups were more than 1.5 times higher than in the CG group (p < .05). Genistein played a significant role in regulating aromatase and FSHR gene expression to improve perimenopausal ovarian and uterine function.     

Effects of body condition and supplementation on ovarian function,growth factors and response to estrus synchronization in postpartum beef cows in Tamaulipas,Mexico

ABSTRACT

Eighteen beef cows with their calves were assigned to 3 groups considering body conditions scores at calving (BCSC): T1 (high BCSC, maintained throughout the study); T2 (low BCSC, increased during the study); and T3 (low BCSC, maintained throughout). An estrus synchronization protocol was implemented, with fixed time artificial insemination on day 70. Follicular or luteal growth, and pregnancy rate were similar between groups. Of all cows, five showed multiple ovulations (2–6); increasing number of ovulations reduced preovulatory follicle diameter and individual luteal volume (P?<?0.05), but total luteal volume was greater in cows with 2 or 3 ovulations on day 14 after insemination (P?<?0.05). Estradiol and progesterone levels were associated to follicular and luteal growth, respectively. No difference was found in IGF1 or GDF9 levels between groups or associated to fertility. No association was found between BCS, IGF1 or GDF9 levels and the reproductive process.     

不同盐分条件下硅对两个高羊茅品种生物量分配和营养元素氮、磷、钾吸收利用的影响

频繁的灌溉,使人工草地的高羊茅生长在盐渍化或潜在盐渍化环境中。硅可以抑制植物对Na⁺的吸收,增加对N、P和K⁺的吸收,从而提高植物的耐盐性,且这种影响因植物种类和品种的不同而不同。本研究采用盆栽试验,研究了不同程度盐生境下施硅对两个高羊茅品种（抗性弱的K31和抗性强的XD）生物量和植株N、P、K⁺、Na⁺含量的影响。结果表明,随着盐浓度的增加,两个高羊茅品种地上和地下生物量、N、P、K⁺含量降低,Na⁺含量增加。施硅对地上和地下生物量、N、P、K⁺、Na⁺含量的影响与盐浓度有关,在中低盐浓度下,施硅增加了高羊茅的地上、地下生物量、根冠比、N、P、K⁺ 含量、K⁺/ Na⁺ 值,降低了Na⁺含量。高盐浓度时,施硅对高羊茅的生物量和N、P、K⁺、Na⁺含量没有影响。施硅对两个高羊茅品种地上和地下生物量、Na⁺、P含量的影响相似,对K⁺、N含量的影响不同,硅对耐盐性较强的XD地上部K⁺及N含量的有利影响优于耐盐性较弱的K31。结果表明,在低中盐浓度条件下,施硅可以促进高羊茅的生长,并且对耐盐性较强的高羊茅品种XD更为有利。     

Effect of induced body condition score differences on physiological response,productive and reproductive performance of Malpura ewes kept in a hot,semi‐arid environment

This study was undertaken to study the influence of induced body condition score (BCS) differences on physiological response, productive and reproductive performance of Malpura ewes to optimise BCS for these ewes for maximising production making it economically viable. The study was conducted for a period of 1 year using thirty healthy Malpura ewes (2–4 year old). The animals were randomly divided and different BCS was induced within three groups named Group I (BCS 2.5; n = 10), Group II (BCS 3.0–3.5; n = 10) and Group III (BCS 4.0; n = 10). The parameters included in the study were allometric measurements, physiological response, wool yield and reproductive performance. BCS had a significant influence on allometric measurements, respiration rate and different reproductive parameters studied, while wool production differed significantly during spring and non‐significantly during autumn. The results revealed that the reproductive performance of Malpura ewes with a BCS of 3.0–3.5 was better in comparison with the groups with lower and higher BCS. It may be concluded from this study that an active management of breeding sheep flock to achieve a BCS of 3.0–3.5 may prove to result in an economically viable return from these flocks.     

锰中毒对鸡肝脏细胞色素P450酶系及CYP2H1 mRNA转录水平的影响

本研究旨在探讨锰对公鸡肝脏细胞色素P450酶系的影响。50日龄海兰褐公鸡400只,随机分为4组,分别在饲料中添加0、600、900、1 800 mg.kg-1MnCl2建立亚慢性锰中毒模型,于30、60、90 d采取肝脏检测肝微粒体细胞色素P450酶系活性以及CYP2H1基因转录水平的变化。结果显示,细胞色素P450、b5含量,氨基吡啉-N-脱甲基酶(AND)和苯胺-4-羟化酶(AH)活性在各个时间点随染锰剂量的增加,基本呈降低趋势,且高剂量组均极显著(P0.01)低于正常组,低、中剂量组有高于正常组的情况。NADPH-细胞色素C还原酶(CR)和红霉素-N-脱甲基酶(ERND)的活性的变化规律不明显,30和60 d NADPH-细胞色素C还原酶活性呈降低趋势,而90 d时呈升高趋势,且高剂量组极显著(P0.01)高于正常组。红霉素-N-脱甲基酶在30 d时呈升高趋势,60和90 d时呈波动性降低变化,且高剂量组均极显著(P0.01)低于正常组。在各个时间点,CYP2H1 mRNA的转录水平除30 d低、高剂量组,60 d中剂量组,90 d低剂量组高于正常组外,其他组均低于正常组。结果提示,锰中毒可影响鸡肝脏细胞色素P450酶系以及CYP2H1 mRNA的转录水平。