Tobacco smoke-dependent changes in cytochrome P450 1A1, 1A2, and 2E1 protein expressions in fetuses, newborns, pregnant rats, and human placenta

Tobacco smoke (TS) was described as a mixture of numerous cytochrome P450 (P450) substrates, inducers, and inhibitors. These inducers and inhibitors may modify drug clearance and xenobiotic or endogenous metabolism affecting P450s expression. In the present study, the effect of gestation and TS on: (1) cytochrome P450 CYP1A1, CYP1A2, and CYP2E1 protein expressions, and (2) cytochrome P450-linked microsomal enzyme activities, were studied in fetal rat liver, rat, and human placenta and in newborn and adult rat hepatic and extrahepatic tissues. Non-pregnant and pregnant 4-month-old female Wistar rats were exposed to TS (500, 1,000, or 1,500 mg carbon monoxide per m³ air) in a toxicological chamber for 3 weeks (6 h daily, 5 days weekly). Human placentas were sampled from non-smoking, passive smoking, or active smoking primiparas. The efficacy of exposure was assessed by measuring urine cotinine levels. The TS-dependent inductory effect on the expression of CYP1A1 and 1A2 and related monooxygenase activities, and the inhibitory/inductory effect on CYP2E1 expression in rat tissues were observed. Pregnancy was associated with decreased levels of constitutive CYP1A1 and 2E1 in hepatic and extrahepatic tissues, TS-inducible CYP1A2 expression in the liver, and CYP1A1 expression in lungs and heart, but had no inhibitory effect on TS-inducible CYP1A1 and 2E1 expression, EROD, and P450-cooperated enzyme activities in the liver, kidney, and, in the latter case, in the heart. The presence of TS-induced CYP1A1 protein was confirmed in rat and human placenta and showed in newborn liver and lungs. CYP1A2 and 2E1 proteins were detectable in fetal rat liver. It was concluded that the expression of CYP1A1, 1A2, and 2E1, which metabolize some drugs and activate carcinogens, is controlled by age-, pregnancy-, and tissue-specific regulatory mechanisms in rats. Gestational differences in the regulation of expression of CYP1A subfamily members are not excluded. CYP1A1 and 2E1, but not CYP1A2 inductory mechanisms seem to be functional in fetal liver at day 21 of pregnancy but they appeared to be uninducible under a TS exposure. In TS-exposed pregnant females and fetuses the effects of metabolic activation of CYP1A1 and 1A2 substrates might be reduced because of lower CYP expressions or poor induction, respectively.This paper was presented partially at the following congresses: 7th European ISSX Meeting, Budapest 1999; Eurotox 1999, Oslo; 11th World Conference on Tobacco OR Health, Chicago, 2000; EUROTOX 2001, Istanbul; 6th International ISSX Meeting, Munich, 2001     

Effect of β-naphthoflavone on AhR-regulated genes (CYP1A1, 1A2, 1B1, 2S1, Nrf2, and GST) and antioxidant enzymes in various brain regions of pig

The constitutive and inducible expression of aryl hydrocarbon receptor (AhR) and of the AhR-regulated genes coding for CYP1A1, CYP1A2, CYP1B1, CYP2S1, and Nrf2 was investigated by real-time or traditional PCR in cerebral areas (cortex, cerebellum, midbrain, and hippocampus), blood–brain interfaces (meninges and brain microvessels) and liver obtained from control pigs and from pigs treated with β-naphthoflavone (βNF), a potent AhR agonist. The enzymatic activities of ethoxyresorufin-O-deethylase (EROD), and methoxyresorufin-O-deethylase (MEROD), marker for CYP1A1 and CYP1A2, the GST and various antioxidant enzymes (catalase, superoxide dismutase, GSSG-reductase, and GSH-peroxidase) were also determined in the same CNS regions. The AhR, CYP1A1, CYP1A2, CYP1B1, Nrf2 mRNAs were detected, although at different extent, in all the CNS regions, while CYP2S1 mRNA was detected only in midbrain. In the blood–brain interfaces, the constitutive basal expression of AhR and CYP1A1 was comparable to the hepatic one and even higher for CYP1B1 and Nrf2. The treatment with βNF determined the induction of CYP1A1 and 1B1 (but not of AhR, CYP1A2, and Nrf2) mRNA levels in various CNS areas; notably, CYP1A1 mRNA was increased to about 300-fold in the microvessels. The analysis of enzymatic activities revealed that EROD, but not MEROD, was induced in microsomes but not in mitochondria of all the CNS areas. However, the mitochondrial EROD activities were comparable (in midbrain, meninges) or higher (in cortex, cerebellum, hippocampus) than the microsomal ones, suggesting an important metabolic function of CYP1A1 in this subcellular localization. The activities of GST and antioxidant enzymes were detected in all CNS tissues, with levels lower than the hepatic ones, but found quite evenly distributed and marginally affected by βNF treatment. The high expression of metabolic enzymes found in blood–brain interfaces could represent a very important defence toward toxins of CNS.     

Hexavalent chromium induced ROS formation,Akt, NF-κB,and MAPK activation,and TNF-α and IL-1α production in keratinocytes

In certain cell types, it has been found that, hexavalent chromium could increase ROS formation, activate cell signaling and stimulate the release of cytokines. But, in keratinocytes, these effects have not yet fully been demonstrated. Our aim is to observe the above effects of hexavalent chromium on keratinocytes. By utilizing HaCaT cells and the skin of albino guinea pigs, we showed that hexavalent chromium could increase ROS formation, activate the Akt, NF-kB, and MAPK pathways as well as increase the production of cytokines, including TNF-α and IL-1α. The release of these cytokines from keratinocytes is considered to be a key participant in the pathogenesis of contact hypersensitivity. Among cement workers, chromium hypersensitivity is an important occupational skin disease issue. Therefore, the observations of our study help us better understand the role of hexavalent chromium on the development of chromium hypersensitivity, which might provide clues for clinicians in the development of chemopreventative agents for the prevention of chromium hypersensitivity among cement workers.     

Life Stage,Alcohol Consumption Patterns,Alcohol‐Related Consequences,and Gender 1

This paper presents findings from a European collaborative study. A common framework for reanalysis of existing data was devised. Alcohol‐related problems encountered were classified as “internal”; and “external.”; Logistic regression analyses were then conducted to predict lifetime presence of any internal problem, any external problem, and any problem at all. The predictor variables were gender, life stage (corresponding roughly to young, middle and older age), past year's drinking level in four categories of grams of alcohol per month, and past year's “binge”; drinking. All four predictor variables were associated with the presence of alcohol‐related problems, with women and retired people having fewer problems and heavy drinkers and binge drinkers having more. At all levels of alcohol consumption, men were more likely than women to experience at least one adverse consequence. Internal problems were more common than external problems. Country differences are discussed and recommendations are made for further studies.     

Proteomic analysis of trichloroethylene-induced alterations in expression, distribution, and interactions of SET/TAF-Iα and two SET/TAF-Iα-binding proteins, eEF1A1 and eEF1A2, in hepatic L-02 cells

Emerging evidence indicates that trichloroethylene (TCE) exposure causes severe hepatotoxicity. However, the mechanisms of TCE hepatotoxicity remain unclear. Recently, we reported that TCE exposure up-regulated the expression of the oncoprotein SET/TAF-Iα and SET knockdown attenuated TCE-induced cytotoxicity in hepatic L-02 cells. To decipher the function of SET/TAF-Iα and its contributions to TCE-induced hepatotoxicity, we employed a proteomic analysis of SET/TAF-Iα with tandem affinity purification to identify SET/TAF-Iα-binding proteins. We identified 42 novel Gene Ontology co-annotated SET/TAF-Iα-binding proteins. The identifications of two of these proteins (eEF1A1, elongation factor 1-alpha 1; eEF1A2, elongation factor 1-alpha 2) were confirmed by Western blot analysis and co-immunoprecipitation (Co-IP). Furthermore, we analyzed the effects of TCE on the expression, distribution and interactions of eEF1A1, eEF1A2 and SET in L-02 cells. Western blot analysis reveals a significant up-regulation of eEF1A1, eEF1A2 and two isoforms of SET, and immunocytochemical analysis reveals that eEF1A1 and SET is redistributed by TCE. SET is redistributed from the nucleus to the cytoplasm, while eFE1A1 is translocated from the cytoplasm to the nucleus. Moreover, we find by Co-IP that TCE exposure significantly increases the interaction of SET with eEF1A2. Our data not only provide insights into the physiological functions of SET/TAF-Iα and complement the SET interaction networks, but also demonstrate that TCE exposure induces alterations in the expression, distribution and interactions of SET and its binding partners. These alterations may constitute the mechanisms of TCE cytotoxicity.     

Effects of saffron and its constituents, crocin-1, crocin-2, and crocetin on α-synuclein fibrils

Journal of Natural Medicines - Saffron, the stigma of Crocus sativus Linné (Iridaceae family), has been known to inhibit aggregation of β-amyloid, a nerve tissue protein. α-Synuclein...     

Effects of dexamethasone and ibuprofen on LPS-induced gene expresion of TNF_ α,IL-1β,and MIP-1α in rat lung

研究地塞米松（Ｄｅｘ）和布洛芬（Ｉｂｕ）对脂多糖（ＬＰＳ）诱导的大鼠肺ＴＮＦα、ＩＬ-１β和ＭＩＰ-１α基因表达的影响．方法：荧光法测定肺中伊文斯蓝含量，Ｓｌｏｔｂｌｏｔ对细胞因子ｍＲＮＡ表达相对定量．结果：腹腔注射ＬＰＳ导致大鼠肺中ＴＮＦα、ＩＬ-１β和ＭＩＰ-１αｍＲＮＡ表达明显增加，与ＬＰＳ剂量有依赖关系，峰值分别在２，６，１２小时．在ＬＰＳ前１小时给药，Ｄｅｘ５０ｍｇ·ｋｇ－１和Ｉｂｕ９０ｍｇ·ｋｇ－１均明显降低肺中伊文斯蓝含量，同时ＴＮＦα、ＩＬ-１β和ＭＩＰ-１αｍＲＮＡ表达量亦明显减少．结论：ＬＰＳ诱导大鼠肺中ＴＮＦα、ＩＬ-１β和ＭＩＰ-１α基因表达，Ｄｅｘ和Ｉｂｕ通过抑制细胞因子表达而减轻肺损伤．     

Design,Synthesis, and Pharmacological Evaluation of Fluorescent and Biotinylated Antagonists of ρ1 GABAC Receptors

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Inhibitory evaluation of oligonol on α-glucosidase,protein tyrosine phosphatase 1B,cholinesterase, and β-secretase 1 related to diabetes and Alzheimer’s disease

Oligonol is a low-molecular-weight form of polyphenol that is derived from lychee fruit extract and contains catechin-type monomers and oligomers of proanthocyanidins. This study investigates the anti-diabetic activities of oligonol via α-glucosidase and human recombinant protein tyrosine phosphatase 1B (PTP1B) assays, as well as its anti-Alzheimer activities by evaluating the ability of this compound to inhibit acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-site amyloid precursor protein cleaving enzyme 1 (BACE1). Oligonol exhibited potent concentration-dependent anti-diabetic activities by inhibiting α-glucosidase and PTP1B with IC₅₀ values of 23.14 µg/mL and 1.02 µg/mL, respectively. Moreover, a kinetics study revealed that oligonol inhibited α-glucosidase (K _i = 22.36) and PTP1B (K _i = 8.51) with characteristics typical of a mixed inhibitor. Oligonol also displayed potent concentration-dependent inhibitory activity against AChE and BChE with IC₅₀ values of 4.34 µg/mL and 2.07 µg/mL, respectively. However, oligonol exhibited only marginal concentration-dependent BACE1 inhibitory activity with an IC₅₀ value of 130.45 µg/mL. A kinetics study revealed mixed-type inhibition against AChE (K _i = 4.65) and BACE1 (K _i = 58.80), and noncompetitive-type inhibition against BChE (K _i = 9.80). Furthermore, oligonol exhibited dose-dependent inhibitory activity against peroxynitrite (ONOO^?)-mediated protein tyrosine nitration. These results indicate that oligonol has strong preventative potential in diabetes mellitus and in Alzheimer’s disease.     

A comparison of the central actions of prostaglandins A1, E1, E2, F1α, and F2α in the rat

The effect of prostaglandins (PGs) A₁, E₁, E₂, F₁, and F₂ administered intraventricularly at doses of 0.02–4.0 g/rat were studied in some behavioral, antinociceptive and anticonvulsant tests in rats. Exploratory and locomotor activity were decreased by all PGs except A₁ and F₂ which had no effect on locomotor activity. All PGs studied, except A₁, induced hyperthermia and afforded protection in the hot-plate analgesic test and against maximal electroshock seizures.     

A comparison of the central actions of prostaglandins A1, E1, E2, F1α, and F2α in the rat

Prostaglandins (PGs) injected into the right lateral brain ventricle (i.v.c.) of the rat increased the sleeping time induced by hexobarbital, chloral hydrate, and ethanol. PGE₁ and PGE₂ intensified chlorpromazine-induced catalepsy, inhibited amphetamine hyperactivity, and significantly depressed the amphetamine-induced stereotypy. NA concentrations were decreased by PGE₁ and PGE₂ and were increased by PGF₂. PGF₂ increased both 5-HT and 5-HIAA levels in rat brain. Total ACh concentrations were increased by PGF₁ and PGF₂. PGE₁, PGE₂, and PGF₂ enhanced the turnover of NA, DA, and 5-HT. PGE₂ counteracted the decreased activity induced by -MT and abolished the hypothermic action of -MT. PGF₂ had little effect on the activity of PCPA pretreated rats, whereas the higher doses of PGF₂ increased body temperature in these animals.     

TGF-β1 Signalling, Connecting Aberrant Inflammation and Colorectal Tumorigenesis

TGF-β1 is an anti-inflammatory cytokine recognised as a key regulator of immunological homeostasis and inflammatory responses. Furthermore, TGF-β1 is important for the regulation of cell growth, differentiation and apoptosis in a wide range of tissues including the intestinal epithelium. Reduced TGF-β1 activity is thought to be responsible for the development of autoimmune disorders in several pathological conditions, including inflammatory bowel disease [IBD]. Although the cause of IBD is not yet known, research has shown that a number of factors may be involved including environment, diet and genetics, as well as cytokine exposure. Importantly, IBD is also associated with an increased lifetime risk of developing colorectal cancer, which remains the fourth most common cancer worldwide, representing a significant therapeutic challenge. As functionally implicated in both maintenance of the immune response and tissue homeostasis in the colon, TGF-β1 signalling potentially sits at the crossroads between aberrant inflammation and colorectal tumorigenesis. Hence, the purpose of this paper is to review the evidence for cross talk between TGF-β1 signalling and pathways important for colorectal tissue homeostasis, with the emphasis on understanding how deregulation of TGF-β1 signalling contributes not only to aberrant inflammatory disease but also to colorectal tumour progression.     

Long-term α1A-adrenergic receptor stimulation improves synaptic plasticity, cognitive function, mood, and longevity

The role of α(1)-adrenergic receptors (α(1)ARs) in cognition and mood is controversial, probably as a result of past use of nonselective agents. α(1A)AR activation was recently shown to increase neurogenesis, which is linked to cognition and mood. We studied the effects of long-term α(1A)AR stimulation using transgenic mice engineered to express a constitutively active mutant (CAM) form of the α(1A)AR. CAM-α(1A)AR mice showed enhancements in several behavioral models of learning and memory. In contrast, mice that have the α(1A)AR gene knocked out displayed poor cognitive function. Hippocampal brain slices from CAM-α(1A)AR mice demonstrated increased basal synaptic transmission, paired-pulse facilitation, and long-term potentiation compared with wild-type (WT) mice. WT mice treated with the α(1A)AR-selective agonist cirazoline also showed enhanced cognitive functions. In addition, CAM-α(1A)AR mice exhibited antidepressant and less anxious phenotypes in several behavioral tests compared with WT mice. Furthermore, the lifespan of CAM-α(1A)AR mice was 10% longer than that of WT mice. Our results suggest that long-term α(1A)AR stimulation improves synaptic plasticity, cognitive function, mood, and longevity. This may afford a potential therapeutic target for counteracting the decline in cognitive function and mood associated with aging and neurological disorders.     

The contribution of α 1-acid glycoprotein,lipoproteins, and albumin to the plasma binding of perazine,amitriptyline, and nortriptyline in healthy man

Summary Parameters for the binding of perazine (PER), amitriptyline (AT) and nortriptyline (NT) to plasma and to single plasma proteins were determined by equilibrium dialysis. The highest affinity (K at least 10⁵ M^–1) and lowest capacity (first site 1 mol/mol) towards all three drugs was exhibited by ₁-acid glycoprotein (₁-AGP). From the parameters, ₁-AGP was estimated to contribute 43% to total binding of PER and 49 and 31%, respectively, to AT and NT binding in samples with normal protein concentrations. Fractions bound to total lipoproteins would amount to 32% (PER), 40% (AT) and 52% (NT), respectively, while the contribution of albumin would range from 11% (AT) to 25% (PER). The extent of the binding to plasma was compared with that to single proteins and their mixtures. Binding to combinations of ₁-AGP, lipoproteins and albumin exceeded that to plasma with PER, but not with AT and NT. This leads to the assumption that additional plasma constitutents interfere with PER binding.     

Comparison of bidirectional lamivudine and zidovudine transport using MDCK,MDCK–MDR1, and Caco-2 cell monolayers

Bidirectional transport studies were conducted using Caco-2, MDCK, and MDCK–MDR1 to determine P-gp influences in lamivudine and zidovudine permeability and evaluate if zidovudine permeability changes with the increase of zidovudine concentration and/or by association of lamivudine. Transport of lamivudine and zidovudine separated and coadministrated across monolayers based on these cells were quantified using LC–MS–MS. Drug efflux by P-gp was inhibited using GG918. Bidirectional transport of lamivudine and zidovudine was performed across MDCK–MDR1 and Caco-2 cells. Statistically significant transport decrease in B → A direction was observed using MDCK–MDR1 for zidovudine and MDCK–MDR1 and Caco-2 for lamivudine. Results show increased transport in B → A and A → B directions as concentration increases but data from P_app increase in both directions for both drugs in Caco-2, decrease in MDCK, and does not change significantly in MDCK–MDR1. Zidovudine transport in A → B direction increases when coadministrated with increasing lamivudine concentration but does not change significantly in B → A direction. Zidovudine and lamivudine are P-gp substrates, but results assume that P-gp does not affect significantly lamivudine and zidovudine. Their transport in monolayers based on Caco-2 cells increase proportionally to concentration (in both directions) and zidovudine transport in Caco-2 cell monolayer does not show significant changes with lamivudine increasing concentrations. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:4413–4419, 2009     

Epinephrine,phenylephrine, and methoxamine induce infiltrative anesthesia via α1-adrenoceptors in rats

Aim:

To assess whether epinephrine, phenylephrine, and methoxamine act via certain subtypes of adrenoceptors to exert their local anesthetic activity.

Methods:

We investigated cutaneous anesthesia from adrenoceptor agonists and/or antagonists in conscious, unanesthetized Sprague-Dawley male rats (weight 200−250 g). Cutaneous anesthesia was evidenced by a block of the cutaneous trunci muscle reflex, which is characterized by reflex movement of the skin over the back produced by twitches of lateral thoracispinal muscles in response to local dorsal cutaneous noxious pinprick.

Results:

Local infiltration of epinephrine, L-phenylephrine, or methoxamine alone induces cutaneous anesthesia in rats in a dose-dependent way. Epinephrine is found to be 19 and 29 times more potent than those of methoxamine and L-phenylephrine, respectively. The cutaneous anesthesia induced by epinephrine, phenylephrine, or methoxamine can be significantly reduced by α₁-adrenoceptor antagonists (eg, prazosin), α1, α2-adrenoceptor antagonist, α_1A-adrenoceptor antagonist (eg, 5-methylurapdil), α_1B-adrenoceptor antagonist (eg, chloroethylclonidine), or α_1D-adrenoceptor antagonist (eg, BMY7873).

Conclusion:

Our results indicate that epinephrine, phenylephrine and methoxamine all act mainly via mixed subtypes of α₁-adrenoceptors to induce cutaneous anesthesia in the rat.     

Esmolol,an ultrashort-acting,selective β1-adrenoceptor antagonist: pharmacodynamic and pharmacokinetic properties

The effects of esmolol at different rates of infusion (100, 250 and 500 g·kg^–1 BW·min^–1) were compared with -adrenoceptor occupancy (₁ and ₂, estimated by a subtype selective radioreceptor assay) and plasma concentrations of esmolol and its acid metabolite were measured by HPLC. Up to a rate of infusion of esmolol of 500 g·kg^–1 BW·min^–1 there was a maximal ₁-receptor occupancy of 84.7% while ₂-receptor occupancy was below the detection limit; confirming the ₁ selectivity of esmolol. Exercise-induced increases in heart rate and systolic blood pressure were reduced by esmolol in a dose-dependent manner. The estimated EC₅₀ values of rate of infusion for the reduction in heart rate and systolic blood pressure during exercise were 113 and 134 g·kg^–1 BW · min^–1, respectively. Additionally, heart rate and systolic blood pressure were reduced moderately at rest. Because of the short elimination half-life of esmolol caused by the rapid hydrolysis to its acid metabolite, 45 min after end of infusion high plasma concentrations of the metabolite (maximally 80 g·ml^–1) but no esmolol were detectable. Since no in vivo effects have been observed, despite the presence of high plasma concentrations of the metabolite, the metabolite did not participate in the observed effects up to an infusion rate of esmolol of 500 g·kg^–1 BW·min^–1. The plasma concentrations of antagonist detected by radioreceptor assay and plasma concentrations of esmolol detected by HPLC showed a good correlation (r=0.97). Since the cardiovascular effects, determined before and 45 min after termination of infusion of esmolol were similar, it can be concluded that the observed effects on heart rate and systolic blood pressure are exclusively mediated by esmolol.Dedicated to Dr. P.Rajagopal, Kuantan Specialist Hospital, Kuantan, Malaysia     

Comparative studies of saponins in 1–3-year-old main roots, fibrous roots, and rhizomes of Panax notoginseng, and identification of different parts and growth-year samples

Notoginsenosides R₁, R₄, Fa, and K (N-R₁, N-R₄, N-Fa, and N-K), as well as ginsenosides Rg₁, Rb₁, Rd, Re, Rf, Rg₂ and Rh₁ (G-Rg₁, G-Rb₁, G-Rd, G-Re, G-Rf, G-Rg₂ and G-Rh₁) in 47 Notoginseng samples including 1-, 2- and 3-year-old main roots, rhizomes and fibrous roots of Panax notoginseng were determined by high-performance liquid chromatography-diode array detection method. Total contents (%) of the 11 saponins were 9.82–14.57 for 2-year old and 14.20–16.00 for 3-year-old rhizomes; 2.72–4.50 for 2-year-old and 1.98–4.92 for 3-year-old fibrous roots; 1.75–3.05 for 1-year-old whole roots; and 3.71–8.98 for 2-year-old and 7.03–11.23 for 3-year-old main roots. Contents of most saponins and total content of 11 saponins were in the order 3- >2- >1-year-old main root samples. G-Rf content, sum of G-Rf and G-Rh₁ were, respectively, 0.08–0.18 and 0.14–0.32 for 2- or 3-year-old rhizomes, and 0.01–0.07 and 0.03–0.10 for 2- or 3-year-old main roots. Combined contents of N-R₁, G-Rg₁ and G-Rb₁ were 5.78–9.37 in 3-year-old main roots, and 2.99–7.13 in 2-year-old main roots, of which nearly one-third of samples were lower than the limit (5 %) in the Chinese Pharmacopoeia. Those of 2- or 3-year-old fibrous roots (1.47–3.83) and 1-year-old whole roots (1.41–2.44) were much lower than the limit, and were considered not suitable for use as Notoginseng. Two-year-old main roots are not appropriate for collection as Notoginseng. Different parts and growth years of P. notoginseng can be identified from each another according to differences in saponin content.