M1,M2受体激动剂和阻滞对犬呼吸的影响

目的：研究Ｍ１和Ｍ２受体激动剂和阻滞剂对犬呼吸的影响，方法：用ＲＭ－８６多导生理记录仪通过胸带式呼吸换能器测定ＲＲ，ＴＶＴＭＶＶ，并取动脉血测ＰＯ２，ｐＣＯ２和ｐＨ。结果发现Ｍ１－Ｒ激动剂Ｐｉｌ和Ｍ２－Ｒ激动剂６β－ＡＮ，ｉｖ或椎动脉给药分别产生呼吸兴奋的和抑制，ＲＲ，ＭＶＶ增高或降低（Ｐ〈０．０５），血气亦出现相应变化，Ｍ１－Ｒ阻滞剂Ｐｉｒ，Ｓｃｏ和Ｍ２－Ｒ阻滞剂ＡＦ－ＤＸ１１６，Ａｔｒ分别拮抗     

Contractile effect of 6β-acetoxy nortropane on human and guinea pig airways

目的：研究６β乙酰氧基去甲托烷（６βＡＮ）对支气管平滑肌的收缩作用．方法：不同ＭＲ拮抗剂对６βＡＮ作用的影响；ＨＰＬＣ法测定６βＡＮ对支气管平滑肌细胞内磷酸肌醇（ＩＰ）的影响；通过６βＡＮ对异丙肾上腺素（Ｉｓｏ）功能拮抗模型，观察６βＡＮ对Ｍ２Ｒ的作用．结果：（１）６βＡＮ对人及豚鼠气管的收缩强度大于ＡＣｈ，分别为６８和２４５倍；（２）阿托品（Ｍ１－Ｍ３）和ｐａｒａｆｌｕｏｒｏｈｅｘａｈｙｄｒｏｓｉｌａｄｉｆｅｎｉｄｏｌ（Ｍ３）抑制６βＡＮ的作用；（３）６βＡＮ引起平滑肌细胞内ＩＰ浓度升高；（４）６βＡＮ对Ｉｓｏ的功能性拮抗作用，在ｍｅｔｈｏｃｔｒａｍｉｎｅ（Ｍ２）０３μｍｏｌ·Ｌ－１时减弱或消失．结论：６βＡＮ通过激活Ｍ３Ｒ引起支气管平滑肌收缩；其对Ｉｓｏ的功能拮抗，部分是激活Ｍ２Ｒ所致．     

6β－乙酰氧基去甲托烷呼吸抑制效应

６β－乙酰氧基去甲托烷（６β－ａｃｅｔｏｘｙｎｏｒｔｒｏｐａｎｅ，６β－ＡＮ）是一种新型Ｍ２受体激动剂，兔１０ｕｇ·ｋｇ－１ｉｖ，犬２，５，２０ｕｇ·ｋｇ－１ｉｖ均导致呼吸频率、潮气量、每分通气量明显减少（Ｐ＜０．０５或０．０１），呈剂量依赖关系。ｐＯ２降低，ｐＣＯ２升高。较小剂量给兔０．５，１．０，２．０，４．０ｕｇ·ｋｇ－１ｉｖａ和犬０．２５，０．５，１．０ｕｇ·ｋｇ－１ｉｖａ亦产生与静脉给药相似的呼吸抑制效应。ＡＦ－ＤＸ１１６能拮抗６β－ＡＮ的呼吸抑制作用，ＰＺ则与６β－ＡＮ产生协同作用。表明６β－ＡＮ有呼吸抑制作用，并可能与其激动呼吸中枢Ｍ２受体有关。     

Characterization of subtype of α_1-adrenoceptor mediating vasoconstriction in perfused rat mesenteric vascular bed

目的：研究去甲肾上腺素（ＮＥ）介导大鼠肠系膜血管床（ＭＶＢ）收缩的α１肾上腺素受体（α１ＡＲ）亚型．方法：用灌流大鼠ＭＶＢ标本收缩功能实验和克隆细胞放射配体结合实验测定α１ＡＲ亚型选择性拮抗剂ｐＡ２和ｐＫｉ,并作相关分析．结果：α１ＡＡＲ选择性拮抗剂ＲＳ１７０５３、ＷＢ４１０１、５ＭＵ及α１ＤＡＲ选择性拮抗剂ＢＭＹ７３７８的ｐＡ２分别为８９８±０２８,９１６±０２０,８．６９±００２和６０３±０２６,Ｓｃｈｉｌｄ作图斜率值与１０差别无显著性．其ｐＡ２值与α１ＡＡＲ的ｐＫｉ相关系数为０９７,与α１Ｂ和α１ＤＡＲ的相关系数分别为０５２和００４．结论：介导外源性ＮＥ收缩大鼠ＭＶＢ的功能性受体为α１ＡＡＲ     

头序木叶中三萜化学成分的研究

从头序木（ＡｒａｌｉａｄａｓｙｐｈｙｌａＭｉｑ）叶中分离到６个三萜化合物，用化学方法和波谱（ＵＶ，ＩＲ，ＭＳ，１ＨＮＭＲ，１３ＣＮＭＲ，１３ＣＤＥＰＴ，ＨＭＱＣ，ＨＭＢＣ）分析，确定其中４种化合物的结构，分别为齐墩果酸（Ｉ），１６β羟基１８βＨ齐墩果酸（Ｉ），齐墩果酸２８ＯβＤ吡喃葡萄糖甙（ＩＩ）和１６β羟基１８βＨ齐墩果酸２８ＯβＤ吡喃葡萄糖甙（ＩＶ）。用ＮＯＥＳＹ谱确定化合物Ｉ的立体构型。以上４个化合物均为首次从该植物中分离到，化合物ＩＶ为新化合物。     

太白木忽木根皮中三萜皂甙成分研究

从太白木忽木（ＡｒａｌｉａｔａｉｂａｉｅｎｓｉｓＺ．Ｚ．ＷａｎｇｅｔＨ．Ｃ．Ｚｈｅｎｇ）根皮中首次分离到四个三萜皂甙，根据理化性质和光谱数据，分别鉴定为齐墩果酸３Ｏ［βＤ吡喃木糖（１→２）］［βＤ吡喃葡萄糖（１→３）］βＤ吡喃葡萄糖醛酸甙（１），ｔａｒａｓａｐｏｎｉｎＶ（２），３Ｏ｛βＤ吡喃木糖（１→２）［βＤ吡喃葡萄糖（１→３）］βＤ吡喃葡萄糖醛酸乙酯｝齐墩果酸２８ＯβＤ吡喃葡萄糖甙（３）和３Ｏ｛βＤ吡喃木糖（１→２）［βＤ吡喃葡萄糖（１→３）］βＤ吡喃葡萄糖醛酸丁酯｝齐墩果酸２８ＯβＤ吡喃葡萄糖甙（４）。１为新天然产物，３和４为新化合物，分别命名为太白木忽木皂甙ＶＩ（ｔａｉｂａｉｅｎｏｓｉｄｅＶＩ）、太白木忽木皂甙ＶＩＩ（ｔａｉｂａｉｅｎｏｓｉｄｅＶＩＩ）和太白木忽木皂甙ＶＩＩ（ｔａｉｂａｉｅｎｏｓｉｄｅＶＩＩ）。     

Protective Effect of Tetrandrine against Excitatory Amino Acids induced Neuronal Injury in Cortical Culture

兴奋性氨基酸类神经毒剂与粉防己碱（ｔｅｔｒａｎｄｒｉｎｅ，Ｔｅｔ）共同作用于原代培养胎鼠大脑皮层神经元２４小时，发现１０７，１０６ｍｏｌ·Ｌ１Ｔｅｔ明显降低５０μｍｏｌ·Ｌ１谷氨酸（ｇｌｕｔａｍａｔｅ，Ｇｌｕ），３００μｍｏｌ·Ｌ１βＮｍｅｔｈｙｌａｍｉｎｏＬａｌａｎｉｎｅ（ＢＭＡＡ，ＮＭＤＡ受体激动剂）和２０μｍｏｌ·Ｌ１βＮｏｘａｌｙｌａｍｉｎｏＬａｌａｎｉｎｅ（ＢＯＡＡ，ｎｏｎＮＭＤＡ受体激动剂）导致的培养液乳酸脱氢酶（ｌａｃｔａｔｅｄｅｈｙｄｒｏｇｅｎａｓｅ，ＬＤＨ）活性的增高；细胞形态损害减轻，细胞数量增加。对２０μｍｏｌ·Ｌ１ＮＭＤＡ介导的神经元损伤改变无影响。提示Ｔｅｔ对某些Ｇｌｕ类神经毒剂引起的胎鼠大脑皮层神经元损伤有一定保护作用，其机制可能是抑制细胞膜上的Ｎａ＋通道开放，阻止膜去极化而影响电压依赖性Ｃａ２＋通道启动。对ＮＭＤＡ受体可能亦有一定作用。     

Effects of clonidine on myocardial β-adrenergic receptor-adenyl cyclase-cAMP system after scalds in rats

研究可乐定（Ｃｌｏ）对大鼠烫伤后心脏β肾上腺素受体（βＡＲ）腺苷酸环化酶（ＡＣ）环腺苷一磷酸（ｃＡＭＰ）系统的作用．方法：大鼠于９５℃水浴中烫９ｓ，造成背部３０％皮肤全层烫伤．用放射受体分析、间接方法、酶放射化学分析、放射免疫分析分别测定βＡＲ密度和亲和力，ＡＣ和磷酸二酯酶（ＰＤＨ）活性及ｃＡＭＰ生成量．结果：Ｃｌｏ（０３、１０和３０ｍｇ·ｋｇ－１）增加烫伤后１２ｈ心肌βＡＲ密度、ＡＣ活性及ｃＡＭＰ生成量（Ｐ＜００５或００１）；但Ｃｌｏ对烫伤大鼠心肌βＡＲ亲和力、ＰＤＨ活性及正常大鼠上述各项指标均无影响（Ｐ＞００５）．育亨宾００５ｍｇ·ｋｇ－１，部分逆转Ｃｌｏ对βＡＲ密度、ＡＣ活性和ｃＡＭＰ生成的作用；哌唑嗪００３ｍｇ·ｋｇ－１，对Ｃｌｏ的作用无明显影响．结论：Ｃｌｏ抑制烫伤后大鼠心肌βＡＲＡＣｃＡＭＰ系统的变化．     

羟甲芬太尼对慢性缺氧大鼠呼吸的影响

目的 探讨μ阿片受体激动剂对慢性缺氧模型呼吸功能的影响。方法 正常大鼠侧脑室注射羟甲芬太尼（Ｏｈｍｅｆｅｎｔａｎｙｌ，ＯＭＦ）后，观察记录呼吸频率（ＲＲ）；侧脑室微量注射阿片受体拮抗剂纳洛酮（ＮＬＸ）、ＯＭＦ，测定ＲＲ、潮气量（ＶＴ）及血气指标，并对每分通气量（ＭＶ）与ＰａＣＯ２作线性回归分析。结果 正常大鼠侧脑室注射ＯＭＦ后，ＲＲ显著下降（Ｐ＜０．０５）。慢性缺氧模型侧脑室注射ＯＭＦ后显著降低ＲＲ、ＶＴ以及中枢对ＣＯ２的敏感性（Ｐ＜０．０１）。电性缺氧模型侧脑室注射ＮＬＸ后，ＲＲ显著增高（Ｐ＜０．０５），并可增强中枢对ＣＯ２的敏感性。结论 μ阿片受体激动剂通过与中枢阿片受体结合降低ＲＲ、ＶＴ等呼吸指标以及中枢对ＣＯ２的敏感性，从而显著影响慢性缺氧模型的呼吸功能。     

Effect of antisense mitogen-activated protein kinase oligonucleotides on rat vascular smooth muscle cell proliferation induced by EGF in vitro

目的：探讨丝裂素活化的蛋白激酶（ＭＡＰＫ）反义寡核苷酸（ＯＤＮ）对表皮生长因子（ＥＧＦ）诱导的培养大鼠血管平滑肌细胞增生的抑制作用．方法：用脂质体将ｐ４２和ｐ４４ＭＡＰＫＯＤＮ０．２μｍｏｌ·Ｌ－１转染入大鼠血管平滑肌细胞，设正义及随机ＯＤＮ为对照，用ＷｅｓｔｅｒｎＢｌｏｔ法结合Ｐ８１滤纸法以髓磷脂碱性蛋白为底物测定ＭＡＰＫ活性．［３Ｈ］胸腺嘧啶核苷酸掺入测定平滑肌细胞ＤＮＡ合成．结果：ＭＡＰＫ０ＤＮ能明显抑制ＥＧＦ诱导的ＭＡＰＫ蛋白表达及ＭＡＰＫ活性，并明显抑制血管平滑肌细胞的［３Ｈ］胸腺嘧啶核苷酸掺入．结论：针对ｐ４２和ｐ４４ＭＡＰＫ起始部位设计的１７ｍｅｒＯＤＮ能有效抑制ＥＧＦ诱导的血管平滑肌细胞的增生．     

Simultaneous Pharmacokinetic Model for Rolofylline and both M1-trans and M1-cis Metabolites

Rolofylline is a potent, selective adenosine A1 receptor antagonist that was under development for the treatment of patients with acute congestive heart failure and renal impairment. Rolofylline is metabolized primarily to the pharmacologically active M1-trans and M1-cis metabolites (metabolites) by cytochrome P450 (CYP) 3A4. The aim of this investigation was to provide a pharmacokinetic (PK) model for rolofylline and metabolites following intravenous administration to healthy volunteers. Data included for this investigation came from a randomized, double-blind, dose-escalation trial in four groups of healthy volunteers (N = 36) where single doses of rolofylline, spanning 1 to 60 mg ,were infused over 1–2 h. The rolofylline and metabolite data were analyzed simultaneously using NONMEM. The simultaneous PK model comprised, in part, a two-compartment linear PK model for rolofylline, with estimates of clearance and volume of distribution at steady-state of 24.4 L/h and 239 L, respectively. In addition, the final PK model contained provisions for both conversion of rolofylline to metabolites and stereochemical conversion of M1-trans to M1-cis. Accordingly, the final model captured known aspects of rolofylline metabolism and was capable of simultaneously describing the PK of rolofylline and metabolites in healthy volunteers.

Electronic supplementary material

The online version of this article (doi:10.1208/s12248-012-9443-5) contains supplementary material, which is available to authorized users.KEY WORDS: adenosine A1 receptor antagonist, pharmacokinetics, rolofylline     

Microglial M1/M2 polarization and metabolic states

Microglia are critical nervous system‐specific immune cells serving as tissue‐resident macrophages influencing brain development, maintenance of the neural environment, response to injury and repair. As influenced by their environment, microglia assume a diversity of phenotypes and retain the capability to shift functions to maintain tissue homeostasis. In comparison with peripheral macrophages, microglia demonstrate similar and unique features with regards to phenotype polarization, allowing for innate immunological functions. Microglia can be stimulated by LPS or IFN‐γ to an M1 phenotype for expression of pro‐inflammatory cytokines or by IL‐4/IL‐13 to an M2 phenotype for resolution of inflammation and tissue repair. Increasing evidence suggests a role of metabolic reprogramming in the regulation of the innate inflammatory response. Studies using peripheral immune cells demonstrate that polarization to an M1 phenotype is often accompanied by a shift in cells from oxidative phosphorylation to aerobic glycolysis for energy production. More recently, the link between polarization and mitochondrial energy metabolism has been considered in microglia. Under these conditions, energy demands would be associated with functional activities and cell survival and thus, may serve to influence the contribution of microglia activation to various neurodegenerative conditions. This review examines the polarization states of microglia and their relationship to mitochondrial metabolism. Additional supporting experimental data are provided to demonstrate mitochondrial metabolic shifts in primary microglia and the BV‐2 microglia cell line induced under LPS (M1) and IL‐4/IL‐13 (M2) polarization.

Linked Articles

This article is part of a themed section on Inflammation: maladies, models, mechanisms and molecules. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2016.173.issue-4

Abbreviations

2‐DG

2‐deoxy‐glucose

AMPK

AMP‐activated PK

BBB

blood–brain barrier

CD172 (SIRP1A)

signal‐regulatory protein

CD206

mannose receptor

EAE

experimental autoimmune encephalomyelitis

FA

fatty acid

Fizz1

found in inflammatory zone 1

HK

hexokinase

iNOS

inducible NOS

MHC‐II

major histocompatibility complex‐II

NLRP

nucleotide‐binding oligomerization domain‐like receptor family pyrin domain‐containing

NODs

nucleotide‐binding oligomerization domains

PPP

pentose phosphate pathway

RNS

reactive nitrogen species

ROS

reactive oxygen species

SR

scavenger receptor

TCA

tricarboxylic acid cycle

TLR

Toll‐like receptor

Tables of Links

M3/M1-Selective antimuscarinic tropinyl and piperidinyl esters.

The binding affinities of some tropinyl and piperidinyl esters for the submandibulary glands (M3/M1) and heart ventricle (M2) were determined from displacement experiments using 3H-labelled N-methylscopolamine as radioligand. The antimuscarinic activities of these esters were also evaluated on guinea pig bronchi. The esters inhibited the M3-mediated carbachol-induced contraction of the bronchial smooth muscle and a reasonable correlation was obtained between the binding affinities of the esters for the submandibulary glands (pKM3,M1) and their inhibitory activities (pIC50) on guinea pig bronchi. A promising compound, N-methylpiperidinyl cyclohexylphenylpropionate (NCPP) which combined good antimuscarinic activity (pA2=9.34) with a 20-fold selectivity at the M3/M1 receptors, was identified. Quantitative structure-activity relationships (QSAR) showed that the size of the ester was the main structural feature determining both binding affinity for the M3/M1 receptors and inhibitory activity on guinea pig bronchi. Esters with substituted acyl side chains (fewer hyperconjugable H atoms at the alpha-carbon) are generally associated with better activity and affinity.     

M1 and M3 muscarinic receptor subtypes in rat forebrain.

At least three pharmacologically different muscarinic receptor subtypes (M1, M2 and M3) have been identified in rat brain. While M1 and M2 subtypes can be directly labelled by selective ligands (3H-pirenzepine and 3H-AF-DX 116, respectively), there are no truly selective ligands for the M3 subtype. In the present study, we have investigated a possible method of studying the pharmacological M3 subtype in rat forebrain using the non-selective labelled antagonist 3H-N-methyl-scopolamine (3H-NMS) in the presence of unlabelled pirenzepine to protect the M1 subtype. The results obtained in kinetic experiments using 3H-NMS in presence of 30.10(-9) M unlabelled pirenzepine (Kon 1.2.10(-8) M-1 m-1, Koff 4.7.10(-2) m-1 and Kd 0.4.10(-9) M) are compatible with the studies carried out in rat pancreatic islets and submaxillary gland which contain predominantly the M3 subtype. We have also performed inhibition experiments with the selective antagonist AF-DX 116. Due to the small proportion of M2 receptors present in rat forebrain, this drug is able to discriminate between M1 and non M1 non M2 receptor subtypes in competition experiments with 3H-NMS versus AF-DX 116 (Ki values 0.28.10(-6) M and 4.3.10(-6) M, respectively). When the competition experiments were performed using 3H-NMS in presence of 30.10(-9) M unlabelled pirenzepine, the Ki value obtained was 3.8.10(-6) M, very close to the value obtained for the non M1 non M2 receptor in competition experiments with 3H-NMS versus AF-DX 116 and in excellent agreement with the affinity of this drug for the glandular M3 subtype. All these data suggest that the approach using the non-selective antagonist 3H-N-methyl-scopolamine in presence of unlabelled pirenzepine allows the study of the pharmacological M3 subtype in rat forebrain.     

Stereoselectivity of procyclidine binding to muscarinic receptor subtypes M1, M2 and M4

The goals of the present study were: (1) to investigate the binding properties of (R)- and (S)-procyclidine and two achiral derivatives of muscarinic M1, M2 and M4 receptor subtypes and (2) to identify the interactions which allow these receptors to discriminate between the two stereoisomers. (R)-Procyclidine showed a higher affinity for human neuroblastoma NB-OK 1 muscarinic M1 and rat striatum muscarinic M4 receptors, as compared to rat cardiac M2 receptors. (S)-Procyclidine had a 130-fold lower affinity than (R)-procyclidine for M1 and M4 receptors, and a 40-fold lower affinity for M2 receptors. Pyrrinol, the achiral diphenyl derivative with the cyclohexyl group of (S)-procyclidine replaced by a phenyl group, has an eight-fold lower affinity for M1 and M4 receptors, as compared to (R)-procyclidine, and a three-fold lower affinity for M2 receptors. Hexahydro-procyclidine, the corresponding achiral dicyclohexyl compound, had a 10- to 20-fold lower affinity than (R)-procyclidine for the three receptors. The increase in binding free energy, which is observed when the phenyl and cyclohexyl groups of procyclidine are separately replaced by cyclohexyl and phenyl groups, respectively, was additive in the case of M1, M2 and M4 receptors. This indicates that the muscarinic receptor stereoselectivity was based on the coexistence of two binding sites, one preferring a phenyl rather than cyclohexyl group and the second preferring a cyclohexyl rather than a phenyl group. In addition, there were also binding sites for the hydroxy moiety and the protonated amino group of the ligands. The greater affinity and stereoselectivity of M1 and M4 muscarinic receptors for (R)-procyclidine reflected the better fit of the cyclohexyl group of (R)-procyclidine to the subsite of M1 and M4 as compared to M2 receptors.     

M1 and M3 muscarinic receptors in human pulmonary arteries.

1. Acetylcholine (ACh) and the M1 agonists (McN-A-343 or PD142505) relaxed human isolated pulmonary arteries which were pre-contracted with noradrenaline (10 microM). In preparations where the endothelium had been removed ACh induced a contractile response whereas the M1 agonists (McN-A-343 or PD142505) had no effect. 2. ACh- and McN-A-343-induced relaxations were abolished after treatment of endothelium-intact preparations with the drug combination NG-nitro-L-arginine (L-NOARG: 0.1 mM) and indomethacin (1.7 microM). 3. The affinity (pKB value) for pirenzepine was higher in human pulmonary arteries when tissues were relaxed with McN-A-343 as compared with ACh (pKB values, 7.71 +/- 0.30 (n = 4) and 6.68 +/- 0.15 (n = 8), respectively). In addition, the affinity for pFHHSiD against McN-A-343- and ACh-induced relaxations was 6.86 +/- 0.13 (n = 3) and 7.35 +/- 0.11 (n = 9) respectively. 4. The low affinities for methoctramine in human isolated pulmonary arteries with the endothelium either intact or removed, suggested the lack of involvement of M2 and M4 receptors in the Ach responses. 5. Phenoxybenzamine (3 microM: 30 min) abolished both ACh contraction and relaxation in human pulmonary artery. The ACh contraction was present when the phenoxybenzamine treatment was preceded by incubation with pFHHSiD (2 microM) but not with pirenzepine (1 microM). In addition, the ACh relaxation was present when preparations were treated with either pFHHSiD (2 microM) or pirenzepine (1 microM), before exposure to phenoxybenzamine. 6. These results in human isolated pulmonary arteries support the notion that only M3 receptors, on smooth muscle, mediate the ACh-induced contraction whereas M3 and M1 receptors are involved in the endothelium-dependent ACh-induced relaxation.     

Glutathione-S-transferase M1, M3, T1 and P1 polymorphisms and susceptibility to non-small-cell lung cancer subtypes and hamartomas.

Polymorphic glutathione-S-transferase (GST) genes causing variations in enzyme activity may influence individual susceptibility to lung cancer. In this case-control study (consisting of 389 Caucasian lung cancer patients, including 151 adenocarcinomas (ACs) and 172 squamous cell carcinomas (SCCs), and 353 hospital control subjects without malignant disease, genotype frequencies for GSTM1, GSTM3, GSTP1 and GSTT1 were determined by polymerase chain reaction (PCR)/ restriction fragment length polymorphism (RFLP)-based methods. While adjusted odds ratios (ORs) indicated no significantly increased risk for lung cancer overall due to any single GST genotype, the risk alleles for GSTM1, GSTM3 and GSTP1 conferring reduced enzyme activity were present at higher frequency in SCC than in AC patients. This is consistent with a reduced detoxification of carcinogenic polycyclic aromatic hydrocarbons (PAHs) from cigarette smoke that are more important for the development of SCC than for AC. An explorative data analysis also identified statistically significantly increased ORs for the combinations GSTT1 non-null and GSTP1 GG or AG for lung cancer overall (OR 2.23, CI 1.11-4.45), and for SCC (OR 2.69, CI 1.03-6.99). For lung cancer overall, and especially among SCC patients, the GSTT1 null genotype was underrepresented (SCC 11.2% v. control subjects 19%, P = 0.026, OR 0.57, CI 0.30-1.06). Additionally, in 28 patients with hamartomas, the GSTT1 null genotype was also protective (P = 0.013), while GSTP1 variant allele carriers were overrepresented (OR 2.48, CI 1.06-6.51). In conclusion, GST genotypes may act differently, either by detoxifying harmful tobacco carcinogens and/or by eliminating lung cancer chemopreventive agents. The latter role for GSTT1 would explain the observed lower risk of SCC and hamartoma associated with GSTT1 null. Further confirmatory studies are required.     

Modulation of macrophage activity by aflatoxins B1 and B2 and their metabolites aflatoxins M1 and M2

Aflatoxins are natural contaminants frequently found both in food and feed. Many of them exert immunomodulatory properties in mammals; therefore, the aim of the current study was to investigate immune-effects of AFB1, AFB2, AFM1 and AFM2, alone and differently combined, in J774A.1 murine macrophages. MTT assay showed that AFB1, alone and combined with AFB2, possess antiproliferative activity only at the highest concentration; such effect was not shown by their hydroxylated metabolites, AFM1 and AFM2, respectively. However, the immunotoxic effects of the aflatoxins evaluated in the current study may be due to the inhibition of production of active oxygen metabolites such as NO. Cytofluorimetric assay in macrophages exposed to aflatoxins (10-100 μM) revealed that their cytoxicity is not related to apoptotic pathways. Nevertheless, a significant increase of the S phase cell population accompanied by a decrease in G0/G1 phase cell population was observed after AFB1 treatment. In conclusion, the results of the current study suggest that aflatoxins could compromise the macrophages functions; in particular, co-exposure to AFB1, AFB2, AFM1 and AFM2 may exert interactions which can significantly affect immunoreactivity.     

Glutathione-S-transferase M1, M3, P1 and T1 polymorphisms and severity of lung disease in children with cystic fibrosis

OBJECTIVES: Progression and severity of lung disease differs markedly and early between patients with cystic fibrosis (CF). We investigated the hypothesis that polymorphisms in the detoxifying enzymes glutathione-S-transferase (GST) could influence phenotypic presentation of lung disease in CF. METHODS: Genotypes for GSTM1, GSTM3, GSTP1 and GSTT1 were determined in a cohort of 146 children with CF by PCR-based methods. Pulmonary function, assessed by spirometric measures of forced expiratory volume in one second (FEV1) and forced vital capacity (FVC), was analysed in children at the age of 9. RESULTS: No association between spirometric measurements, and GSTM1, GSTP1 or GSTT1 genotypes was found. As compared with patients homozygous for GSTM3*A allele, CF children carrying the GSTM3*B allele displayed a significant better lung function, assessed by both mean values of FEV1 and of FVC (respectively P = 0.01 and P = 0.002). These correlations remained significant after adjustment for potential confounding factors (respectively adjusted P = 0.008 and P = 0.002) and also in subgroups of CF patients who carry the deltaF508 CFTR mutation. Haplotype analysis of GSTM3 in combination with GSTM1 indicated that the positive impact of GSTM3*B allele on pulmonary performances was barely influenced by the GSTM1 genotypes of CF children. CONCLUSIONS: These data provide the first evidence suggesting that polymorphism of the GSTM3 gene contributes to clinical severity in CF, which may have prognostic significance and could prompt to start a more targeted therapy in young patients with CF.