Levels of fumonisin B1 in corn naturally contaminated with aflatoxins

Aflatoxins and fumonisin B₁ are hepatotoxic and carcinogenic metabolites produced by Aspergillus flavus and Fusarium moniliforme, respectively. These fungi are common natural contaminants of corn, and both aflatoxins and fumonisin B₁ have been implicated as aetiological agents in animal and human diseases. To determine whether these mycotoxins co-exist on corn under natural conditions, 28 samples from the 1991 Georgia (USA) corn crop were assayed for (total) aflatoxin and fumonisin B₁. 27 samples were positive for aflatoxin, 24 samples were positive for fumonisin B₁, and 23 samples had detectable levels of both. In the positive samples, the mean aflatoxin concentration was 73 ppb (SD = 86), and the average fumonisin B₁ concentration was 0.87 ppm (SD = 0.65). A correlation between aflatoxin and fumonisin B₁ concentrations was not evident. None the less, these results demonstrate that exposure to both mycotoxins can occur simultaneously by consumption of co-contaminated corn.     

Toxigenic fungi and mycotoxins in mature corn silage

To investigate the exposure of livestock and farm workers to mycotoxins during the last months of silage use, the mycoflora and the mycotoxins in a mature silage (11-months-old) were studied. A multimycotoxin method was developed to evaluate the toxigenic in vitro ability of fungal strains. The screening of potentially toxigenic fungi isolated from the mature silage showed that six Fusaria (Fusarium culmorum, Fusarium equiseti, Fusarium graminearum, Fusarium oxysporum,Fusarium solani and Fusarium verticillioides) and one Aspergillus (Aspergillus fumigatus) were able to produce mycotoxins on nutrient agar. Seven major mycotoxins (aflatoxin B₁, citrinin, deoxynivalenol, fumonisin B₁, gliotoxin, ochratoxin A and zearalenone) were also searched in the corn silage by high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS). Among the three mycotoxins (citrinin, gliotoxin and deoxynivalenol) detected in the silage, gliotoxin, a strongly immunosuppressive mycotoxin, occured in the mature silage at level up to 877 ppb, which was associated with the presence of A. fumigatus in the silage.     

安神益脑丸中黄曲霉毒素残留量测定及LC-QQQ/MS确证

目的:建立高效液相色谱-荧光检测器测定安神益脑丸中黄曲霉毒素G2、G1、B2、B1的方法;分析安神益脑丸中黄曲霉毒素的污染情况.方法:待测样品采用80％乙腈作为提取溶剂,经免疫亲和柱净化、高效液相色谱分离、光化学柱后衍生后,通过荧光检测器测定其中黄曲霉毒素的含量;采用超高效液相色谱串联三重四极杆质谱法对以上实验测定结果...     

Immunohistochemical study of proliferating cell nuclear antigen (PCNA) in duckling liver fed with aflatoxin B1 and esterified glucomannan

The effect of esterified glucomannan on aflatoxin B₁ toxicity in ducklings was studied by immunohistochemical staining of proliferating cell nuclear antigen (PCNA) in hepatic cells on formalin-fixed paraffin-embedded liver samples. Cherry Valley ducklings were divided into five groups, 20 birds in each. One of the groups was fed with conventional feed, and the other groups were fed with diet containing 100 ppb aflatoxin B₁, that containing 0.05% esterified glucomannan, or that containing 100 ppb aflatoxin B₁ supplemented with 0.05 or 0.1% esterified glucomannan, from five days of age for one month, and subsequently all the groups were fed with conventional feed for 20 days. Four birds of each group were sacrificed on the 30th, 35th, 40th, 45th and 50th day of feeding, and PCNA on the liver tissue sections was quantitatively analyzed by immunohistochemical staining. The percentage of PCNA-positive hepatocytes was significantly higher in the group given diet containing aflatoxin B₁ than in the other groups, which were not significantly different from each other. The results demonstrate that supplementation of feed with esterified glucomannan is effective in reduction of aflatoxin B₁-induced hepatic injury in ducklings.     

Toxicity assessment of fumonisins using the brine shrimp (Artemia salina) bioassay.

The Fusarium mycotoxins fumonisin B₁ (FB₁) (1) and B₂ (FB₂) (2), their hydrolysed analogues HFB₁ (3) and HFB₂ (4) and the recently discovered fumonisin derivatives N-palmitoyl-HFB₁ (5) and N-carboxymethyl-FB₁ (6) were compared for their toxicity in a short term bioassay using brine shrimp (Artemia salina). The brine shrimp were hatched in artificial sea water and exposed to the fumonisins in microwell plates with a mortality endpoint after 48 hours. LC₅₀ values were calculated after Probit transformation of the resulting data. Of the substances tested, fumonisin B₁ emerged to be the most toxic whereas its N-carboxymethyl analogue was 100-fold less effective. The hydrolysed fumonisins showed a four- to sixfold reduced toxicity compared to FB₁. N-Palmitoyl-HFB₁ had a higher LC₅₀ value than its precursor HFB₁. The brine shrimp assay proved to be a convenient and rapid system for toxicity assessment of this group of mycotoxins.     

Cassia Senna Inhibits Mutagenic Activities of Benzo[a]-pyrene,Aflatoxin B1, Shamma and Methyl Methanesulfonate

Abstract: Ethanol extract of Senokot tablets (Cassia senna concentrate used as vegetable laxative), was found to be non-mutagenic while it inhibited the mutagenicity of benzo[a]pyrene, shamma, aflatoxin B₁ and methyl methanesulfonate in the Ames histidine reversion assay using the Salmonella typhimurium tester strain TA98. While the Senokot extract completely inhibited the mutagenicity of promutagens (i.e. metabolic activation dependent) like benzo[a]pyrene and shamma, it reduced the mutagenic activity of the direct acting mutagen methyl methanesulfonate by only 58%. The mutagen aflatoxin B₁ showed a 25-fold increase in the number of histidine revertants per plate at low concentrations (1.0–4.0 μg/plate) in the presence of metabolic activation system while at high concentrations (10.0–30.0 μg/plate) it proved to be weakly mutagenic (with a 5-fold increase in the number of histidine revertants/plate) without metabolic activation. The Senokot extract completely inhibited the mutagenic effect of low concentrations of aflatoxin B₁ in the presence of metabolic activation but not that resulting from higher concentrations without metabolic activation. The results obtained with benzo[a]pyrene, shamma and aflatoxin B₁ indicated that the antimutagenic effects of Senokot extract could be largely due to an interaction with the metabolic process involved in the activation of procarcinogens. However, the results obtained with methyl methanesulfonate suggested that factors in Senokot may also interact with direct mutagens to produce some antimutagenic effects. An ethanol extract of crude senna leaves found to be weakly mutagenic also inhibited (though less than Senokot) the mutagenic effect of benzo[a]pyrene suggesting that the antimutagenic principle is present in the complex plant material itself.     

Interactions of organic anion transporters and organic cation transporters with mycotoxins

Mycotoxins are secondary metabolites of moulds that which exert adverse effects in humans and animals. It is known that direct cellular toxicity is often associated with increased cellular accumulation of toxic compounds, and membrane transport may be the first fundamental stage in the development of the cytotoxicity. To elucidate the entry pathway for mycotoxins into cells, we have investigated the interactions of human and rat organic anion transporters (hOATs/rOats) and human organic cation transporters (hOCTs) with mycotoxins using cells stably expressing hOATs/rOats/hOCTs. The mycotoxins tested were aflatoxin B1, alpha-zearalenol, citrinin, citrioveridine, cyclopiazonic acid, fumonisin B1, gliotoxin, patulin, penicillic acid, rubratoxin B, and zearalenone. These mycotoxins inhibited organic anion uptake mediated by hOAT1-4, and organic cation uptake mediated by hOCT1-2. By comparing the IC(50) values of mycotoxins for hOATs, it was found that hOAT1 and hOAT3 exhibited higher affinity interactions with mycotoxins than hOAT2 and hOAT4. There was no interspecies difference between humans and rats for the interactions of OATs with mycotoxins except that of OAT3 with rubratoxin B. Finally, we observed that hOAT1-4 and hOCT1-2 mediated the uptake of aflatoxin B1. In conclusion, hOATs and hOCTs interacted with various mycotoxins. Considering the localization of hOATs/rOats and hOCTs, it was suggested that these transporters were the possible entrance pathway for mycotoxins in kidney and liver, leading to the induction of adverse effects in humans and rats.     

维生素治疗和诊断性监测的临床应用

目的:采用电化学方法测定人血清九种维生素浓度,为维生素相关性疾病的诊断和治疗提供依据。方法:于2013年3月至2014年11月,采集新生儿和婴幼儿、孕妇、老年、消耗性疾病等患者肘静脉血,经处理取适量血清与样本处理液震荡混匀,采用LK3000V维生素检测仪测定各维生素血清浓度。结果:2 050例维生素A、D、E,1 894例维生素B₁和维生素C,1 857例维生素B₂和维生素B₆,2 028例维生素B₉、B₁2的检测结果有助于发现维生素血浓度异常个体,可作为维生素相关性疾病诊断和治疗的依据。结论:该方法灵敏、准确、快速、重复性好,可用于人体血清维生素浓度常规检测以及维生素相关性疾病的诊断和治疗。     

Arachidonic acid, an in vivo inhibitor of carrageenin induced granulomas in the rat

Arachidonic acid (AA) injected locally into carrageenin/sponge granulomas, but not if given orally, inhibited granuloma growth. Granuloma macrophage (M0) infiltration was inhibited, and prostaglandin E₂ (PGE₂) synthesis (ng/100 mg granuloma dry weight) stimulated, by AA treatment. M0 adenosine 3′,5′-cyclic monophosphate (cAMP) levels and granuloma exudate volume were not affected. Granuloma M0s incubated in vitro with arachidonic acid synthesised thromboxane B₂ (Txb₂), 6-ketoprostaglandin F₁ (6-ketoPGF₁), and preferentially, PGE₂. The AA inhibition of granuloma growth was possibly mediated via the synthesis of PGE₂.     

Prioritization of Mycotoxins Based on Their Genotoxic Potential with an In Silico-In Vitro Strategy

Humans are widely exposed to a great variety of mycotoxins and their mixtures. Therefore, it is important to design strategies that allow prioritizing mycotoxins based on their toxic potential in a time and cost-effective manner. A strategy combining in silico tools (Phase 1), including an expert knowledge-based (DEREK Nexus^®_, Lhasa Limited, Leeds, UK) and a statistical-based platform (VEGA QSAR©, Mario Negri Institute, Milan, Italy), followed by the in vitro SOS/umu test (Phase 2), was applied to a set of 12 mycotoxins clustered according to their structure into three groups. Phase 1 allowed us to clearly classify group 1 (aflatoxin and sterigmatocystin) as mutagenic and group 3 (ochratoxin A, zearalenone and fumonisin B1) as non-mutagenic. For group 2 (trichothecenes), contradictory conclusions were obtained between the two in silico tools, being out of the applicability domain of many models. Phase 2 confirmed the results obtained in the previous phase for groups 1 and 3. It also provided extra information regarding the role of metabolic activation in aflatoxin B1 and sterigmatocystin mutagenicity. Regarding group 2, equivocal results were obtained in few experiments; however, the group was finally classified as non-mutagenic. The strategy used correlated with the published Ames tests, which detect point mutations. Few alerts for chromosome aberrations could be detected. The SOS/umu test appeared as a good screening test for mutagenicity that can be used in the absence and presence of metabolic activation and independently of Phase 1, although the in silico–in vitro combination gave more information for decision making.     

Aflatoxin deposition and clearance in the eggs of laying hens

Hens fed a diet containing 3310 μg of AFB₁ and 1680 μg of AFB₂ per kg feed for 28 days showed a significant decrease in egg production and egg weights by wk 3 and 4 of feeding, respectively. Transfer of aflatoxins to the eggs occurred rapidly, reaching maximum levels after 4–5 days, and remained relatively constant throughout aflatoxin feeding. The mean values for combined residue levels in eggs were less than 0.5 μg/kg. Levels of AFB₂, AFM₁ and AFM₂ were similar in yolk and albumen while levels of B₁ and B_2a were higher in the yolk. Upon removal of the aflatoxin-containing diet, residues in eggs decreased rapidly. Clearance of aflatoxin residues from the albumen occurred faster than from the yolk. Thus, no residues were detected in the albumen and in the yolk after 5 and 7 days of withdrawal, respectively. No aflatoxin residues could be recovered from whole eggs after feeding the aflatoxin-free diet for 4 days.     

Reversed-phase ion-pair HPLC determination of some water-soluble vitamins in pharmaceuticals

A reversed-phase ion-pair high-performance liquid chromatografic method (RP-IPC) was developed to assay some water-soluble vitamins in solution dosage forms. Vitamins of the B-group B₁, B₂, B₃, and B₆, including vitamin C were determined in Oligovit^® coated tablets. In Beviplex^® coated tablets the vitamins B₁, B₂, B₃, B₆ and p-aminobenzoic acid were analysed. Hexanesulphonic acid sodium salt and triethanolamine in water–methanol were used as mobile phase with adjusting pH to 2.8 with orthophosphoric acid. Phenol was used as an internal standard. For quantitative simultaneous analysis of vitamins in pharmaceutical formulations, the method of internal standard was used. All parameters for the validation of the method are given.     

Characterization of water-soluble glucuronide and sulphate conjugates of aflatoxin B1. 2. Studies in primary cultures of rat hepatocytes

Aflatoxin B1 and some of its metabolites were released from water-soluble aflatoxin conjugates isolated from rat primary hepatocyte cultures and hydrolysed by enzymes (beta-glucuronidase and sulphatase), by acid or by a combination of both treatments. The presence of AFB1 in the hydrolysates was detected on TLC plates, or indicated indirectly by the Ames mutagenicity assay. The aflatoxin conjugates were not mutagenic to Salmonella typhimurium strain TA98 in the presence of rat-liver S-9 mix. However, following enzymatic hydrolysis, the chloroform extract of the hydrolysate was highly mutagenic to the bacteria, indicating the presence of mutagenic AFB1. The conjugates AFB1-glucuronide and AFB1-sulphate are therefore produced from AFB1 in primary cultures of rat hepatocytes.     

Voltammetric determination of vitamins in a pharmaceutical formulation

Direct current polarography and differential pulse polarographic methods have been developed for the qualitative as well as quantitative analysis of vitamin B₁, B₂ and B₆. Thiamin (Vitamin B₁) produced a well-defined wave in 0.1 M KCl at pH 5.2 with E_1/2=−1.2 V and E_p=−1.22 V versus saturated calomal electrode (SCE). Riboflavin (Vitamin B₂) gave two distinct waves in Britton Robinson buffer at pH 1.8 with E_1/2 VALUES=−0.13 and −0.34 V versus SCE and at pH 6.5 with E_1/2=−1.10 V and E_p=−1.2 V versus SCE. Pyridoxin (Vitamin B₆) produced a well-defined wave in Britton Robinson buffer at pH 6.5 with E_1/2=−1.7 V and E_p=−1.68 V versus SCE. All the three Vitamins under study are reversibly reduced at the electrode surface. The number of electrons involved in the electrode process for vitamin B₁ and B₆ is one in each case where as for the two waves of B₂ it is one and two, respectively. This has been confirmed by the measurement of E_3/4–E_1/4 values and also from the log plot slopes for the reduction waves. The wave height of polarogram was found to be proportional to the vitamin concentration. The developed methods have been standardised for the determination of these compounds in pharmaceutical formulation. The concentration of Vitamin B₁, B₂ and B₆ are found to be 9.96, 9.92 and 3.01 mg, respectively in 240 mg of capsule powder of a standard company (name has not been disclosed due to secrecy purpose). The results have been found to be in excellent agreement to that claimed by the manufacturer. The observed data has been subjected to statistical analysis, which revealed high reliability and precision.     

注射用重组人Ⅱ型肿瘤坏死因子受体-抗体融合蛋白对活动性类风湿关节炎患者骨代谢的影响

目的:分析及评价注射用重组人Ⅱ型肿瘤坏死因子受体-抗体融合蛋白(etanercept)对活动性类风湿关节炎患者骨代谢的影响。方法:选取2015年在西南医科大学附属医院风湿免疫科确诊为类风湿关节炎(Rheumatoid Arthritis,RA)的100例骨代谢异常患者,年龄为40~59(51.3±7.6)岁,病程为12~41(29.5±14.1)个月,其中男性23例,女性77例,且所有患者DAS28评分>2.6,均通过双能X线骨密度检测仪及N-端前肽(PINP)、血清Ⅰ型胶原C-末端肽(CTX-I)评估骨代谢情况。根据初始骨密度检测结果,分为类风湿关节炎伴骨质疏松组(A组,58例)及类风湿关节炎伴骨量减少组(B组,42例),A、B组各随机分为两组,A组分为A_1组(29例)和A_2组(29例),B组分为B_1组(21例)和B2组(21例),其中A_1和B_1组给予注射用重组人Ⅱ型肿瘤坏死因子受体-抗体融合蛋白(25mg皮下注射biw×6个月,后改为25mg qw×6个月)+甲氨喋呤(15mg qw)+叶酸片(10mg qw)+硫酸羟氯喹(0.2bid)+钙尔奇D(600mg qd)+阿法骨化醇(0.5μg qd)治疗,A_2和B2组给予甲氨喋呤(15mg qw)+叶酸片(10mg qw)+硫酸羟氯喹(0.2bid)+钙尔奇D(600mg qd)+阿法骨化醇(0.5μg qd)治疗,A_1、B_1组为观察组,A_2、B2组为对照组,各组患者分别治疗前、治疗后6、12月检测股骨颈、颈椎、大转子、Ward三角骨密度值,同时检测PINP、CTX-I水平、并计算DAS28评分。结果:与A_2组比较,A_1组患者在性别构成比、DAS28评分、平均病程、平均发病年龄及初始PINP、CTX-I水平差异无显著性(P>0.05),大转子初始骨密度值明显低于A_2组,差异有显著性(P<0.05)。A_1组股骨颈、Ward三角在治疗6、12个月后骨密度值均高于同期A_2组,颈椎在治疗12个月后骨密度值高于A_2组,大转子在治疗6个月后骨密度值低于A_2组,差异均有显著性(P<0.05)。在治疗6、12个月后,A_1组PINP水平均低于同期A_2组,差异有显著性(P<0.05),A_1组CTX-I水平较同期A_2组降低,尤以12个月后更为显著(P<0.05);与B2组比较,B_1组在性别构成比、平均发病年龄及初始PINP、CTX-I水平差异无显著性(P>0.05),但B_1组DAS28评分较B2组高,平均病程较B2组短,大转子初始骨密度值低于B2组,差异有显著性(P<0.05)。B_1组股骨颈、颈椎、Ward三角在治疗12个月后骨密度值高于同期B2组,大转子在治疗6个月后骨密度值低于B2组,差异均有显著性(P<0.05)。在治疗6、12个月后,B_1组PINP水平均低于同期B2组,差异有显著性(P<0.05),B_1组CTX-I水平较同期B2组降低,尤以12个月后更为显著(P<0.05)。结论:注射用重组人Ⅱ型肿瘤坏死因子受体-抗体融合蛋白可有效阻止活动性类风湿关节炎患者的骨量丢失,改善该类患者异常的骨代谢,随使用时间的延长,效果可能更加显著。     

HPLC 法测定多维元素胶囊（15）中烟酰胺、维生素B1、维生素B2、维生素B6的含量

目的:建立高效液相色谱法测定多维元素胶囊(15)中的烟酰胺、维生素B1、维生素B2、维生素B6的含量.方法:采用Boston Green ODS C18柱(250 mm×4.6 mm,5 μm);流动相:庚烷磺酸钠溶液(取庚烷磺酸钠0.941 g,加冰乙酸10 ml,加水1 000 ml溶解,用NaOH试液调节pH至3.8)-甲醇(70:30);进样量:20 μl;检测波长为280 nm;柱温:30℃;流速1.0 ml·min-1.结果:烟酰胺、维生素B1、维生素B2、维生素B6分别在38.83～349.44,9.88～88.94,4.03～36.25,3.97～35.77 μg·ml-1范围内线性关系良好(r≥0.999 6);平均回收率分别为98.7%(RSD=0.89%),98.7%(RSD=1.03%),99.0%(RSD=1.03%),99.8%(RSD=1.49%).结论:该方法准确,灵敏度高,重复性好,可作为多维元素胶囊(15)的质量控制方法之一.     

人血清水溶性维生素B1、B2、B6和B9高效液相色谱串联质谱联用技术测定方法的建立和验证

目的：建立测定人血清中水溶性维生素B₁、B₂、B₆和B₉的高效液相色谱串联质谱联用法。方法：常规送检患者血清经乙酸乙酯萃取,经反相高效液相色谱分离,采用电喷雾离子化四级杆串联质谱多反应监测模式测定维生素B₁、B₂、B₆和B₉浓度。结果：维生素B₁、B₂、B₆、B₉线性范围分别为1~200,5~40,1~80,5~40 ng·mL^-1;R²值分别为0.991 6,0.996 8,0.992 2,0.991 4;最低定量限分别为1,5,1,5 ng·mL^-1;日内、日间RSD均小于8.5%。结论：所建立方法可用于常规送检患者血清水溶性维生素B₁、B₂、B₆和B₉测定。     

Activity of some respiratory enzymes and cytochrome contents in rat hepatic mitochondria following aflatoxin B1 administration

Effects of aflatoxin B₁ (AFB₁) administration (7 mg/kg body weight i.p.) on rat hepatic mitochondrial respiratory components have been examined. Succinoxidase and cytochrome oxidase activities were decreased in liver mitochondria isolated from rats 12–24 h after AFB₁ treatment. Both enzyme activities returned to normal levels after 48 h. Glutamate dehydrogenase and β-hydroxybutyrate dehydrogenase activities did not show any alterations up to 24 h and thereafter increased at 48–72 h. Succinate dehydrogenase activity was impaired by 41% at 12 h and thereafter was found to be normal. The intramitochondrial cytochrome b content declined at 24–72 h, whereas cytochrome aa₃ content was decreased maximally at 72 h after AFB₁ administration. These observations on mitochondrial enzyme activities and cytochrome contents correlate well with our earlier observations made on hepatic mitochondrial respiratory rates after AFB₁ treatment. The impairment of respiratory functions possibly results from membrane damage and selective modification of gene expression in mitochondria imparted by AFB₁.     

不同来源甲硫氨酸维B1注射剂体外细胞毒性的比较与分析

目的：比较不同来源甲硫氨酸维B₁注射剂体外细胞毒性的差别并寻找差别形成的主要原因。方法：将不同来源甲硫氨酸维B₁注射剂不同浓度的稀释液与小鼠成纤维细胞L-929接触培养,通过倒置相差显微镜观察细胞形态,采用四甲基偶氮唑盐比色法（MTT法）量化细胞毒性,计算相对增殖率,并进行细胞毒性评价。建立甲硫氨酸维B₁注射剂中枸橼酸含量的高效液相色谱检测方法,考察枸橼酸含量与制剂细胞毒性的相关性。结果：7个生产厂家的甲硫氨酸维B₁注射液细胞毒性无明显差别。12个生产厂家的注射用甲硫氨酸维B₁中有11个厂家的样品不同浓度组对L-929的细胞毒性级别为1级或2级。但J厂家的注射用甲硫氨酸维B₁样品（20 mg·mL^-1和10 mg·mL^-1）对L-929的细胞毒性级别为4级,表现为重度毒性。枸橼酸质量浓度3,1.5,0.75 mg·mL^-1的相对增殖率分别为7%、45%、74%,而对应的含等量枸橼酸的制剂浓度（以甲硫氨酸计）20,10,5 mg·mL^-1的相对增殖率分别为6%、28%、53%,细胞毒性试验结果吻合。结论：不同厂家生产的甲硫氨酸维B₁注射剂由于处方工艺不同等,其细胞毒性存在差别。枸橼酸作为注射剂的常用辅料,在高于0.188 mg·mL^-1的浓度下存在细胞毒性,枸橼酸含量与细胞毒性呈正相关性,J厂家样品的重度细胞毒性可能主要源于过高浓度的辅料枸橼酸。建议生产厂家降低枸橼酸添加量,以减少制剂的细胞毒性,提高药品的安全性。     

Evidence for the participation of kinins in Freund's adjuvant-induced inflammatory and nociceptive responses in kinin B1 and B2 receptor knockout mice.

Experiments were designed to investigate the role of kinin B₁ and B₂ receptors in Freund's adjuvant (CFA)-induced inflammation and nociception responses by the use of B₁ and B₂ null mutant mice. Intradermal (i.d.) injection of CFA produced time-dependent and marked hyperalgesic responses in both ipsilateral and contralateral paws of wild-type mice. Gene disruption of the kinin B₂ receptor did not interfere with CFA-induced hyperalgesia, but ablation of the gene of the B₁ receptor reduced the hyperalgesia in both ipsilateral (48±13%, at 12 h) and contralateral (91±22%, at 12 h) paws. Treatment of wild-type mice with the selective B₁ antagonist des-Arg⁹-[Leu⁸]-BK (150 nmol/kg, s.c.) reduced CFA-evoked thermal hyperalgesia, to an extent which was similar to that observed in mice lacking kinin B₁ receptor. I.d. injection of CFA produced a time-related and long-lasting (up to 72 h) increase in paw volume in wild-type mice. A similar effect was observed in B₁ knockout mice. In mice lacking B₂ receptor, the earlier stage of the CFA-induced paw oedema (6 h) was significantly greater compared with the wild-type animals, an effect which was almost completely reversed (76±5%) by des-Arg⁹-[Leu⁸]-BK. This data demonstrates that kinin B₁ receptor, but not B₂ receptor, exerts a critical role in controlling the persistent inflammatory hyperalgesia induced by CFA in mice, while B₂ receptor appears to have only a minor role in the amplification of the earlier stage of CFA-induced paw oedema formation. The results of the present study, taken together with those of previous studies, suggest that B₁ receptor antagonists represent a potential target for the development of new drugs to treat persistent inflammatory pain.