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Biomedical subjects

E Kriek

Publications and source records attributed to E Kriek.

At least 37 records · Page 2Linked to original sources
PubMed1991

Immunocytochemical visualization of DNA adducts in mouse tissues and human white blood cells following treatment with benzo[a]pyrene or its diol epoxide. A quantitative approach.

The formation and stability of benzo[a]pyrene DNA adducts were studied in tissues of BALB/c mice exposed to benzo[a]pyrene (B[a]P). The DNA adducts were visualized with an immunocytochemical peroxidase staining technique using an antiserum specific for the major B[a]P-derived adduct in DNA [(+/-)trans-7,8-dihydroxy-anti-9,10-epoxy-7,8,9,10- tetrahydrobenzo[a]pyrene (BPDE-N2-dG)]. The nuclear staining density was measured by microdensitometry. When mice were treated with an increasing dose of B[a]P the nuclear staining increased in the tissues studied (lung, heart and kidney). A linear relationship was found between the immunocytochemical nuclear staining signal and the actual DNA adduct level in the lung as measured by 32P-postlabeling. Maximum adduct formation was found 5 days after a single i.p. injection of B[a]P. Adduct levels decreased gradually after 7 days, but even after 61 days a slight specific staining was still present, suggesting that not all adducts had disappeared at that time. As judged from the disappearance of [3H]thymidine from prelabeled DNA the loss of adducts from the lung was not a result of DNA repair but one of cell turnover. In human white blood cells B[a]P-derived adducts could be detected after in vitro incubation with the reactive metabolite of B[a]P (BPDE). Dose-response studies demonstrated a positive relationship between BPDE-DNA adduct formation, the immunocytochemical staining signal and the BPDE concentration in the culture medium.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed1991

Does regional norepinephrine spillover represent local sympathetic activity?

Regional spillover of norepinephrine (NE), based on isotope dilution and single-compartment steady-state kinetics, is considered one of the best parameters for estimating organ sympathetic activity. However, the effects of local changes in clearance of NE on the spillover have not yet been investigated. We studied local NE kinetics and clearance in the forearm of 10 healthy subjects using intra-arterial infusions of NE, tritiated NE, the neuronal uptake inhibitor desipramine, and tyramine, which competes with NE for the neuronal uptake carrier. Before and during complete blockade of neuronal uptake by desipramine the venous concentration-time curves for tritiated NE and for NE released by tyramine were biexponential, consistent with the presence of (at least) two compartments for circulating tritiated NE and for locally released NE. The time constants for tyramine-induced release of NE and, in the same subjects during desipramine infusion, for tritiated NE were almost equal at the same level of forearm blood flow. This argues against possible diffusion or transport differences for NE to and from the circulation and the synapse. The regional intrinsic clearance capacity (a measure of the maximal ability of an organ to irreversibly remove drug by all pathways in the absence of any flow limitations) for NE decreased in the forearm by 65% (p less than 0.01) during neuronal uptake blockade by desipramine; the forearm clearance decreased by 59% (p less than 0.001), whereas the spillover rate of NE increased from 33 +/- 5 to 63 +/- 11 pmol.min-1 (p less than 0.05). Nitroprusside-induced increments in blood flow increased the spillover of NE from 18 +/- 4 to 35 +/- 6 pmol.min-1 (p less than 0.01); the clearance of circulating NE also increased (by 58%, p less than 0.05), and the intrinsic clearance capacity remained unchanged. This demonstrates that regional spillover of NE is markedly influenced by local changes in clearance and flow. The new parameter plasma appearance rate of NE is proposed. Although also derived from isotope dilution, this parameter may better approximate the regional entry of NE into the blood pool than spillover. This is corroborated by the nonsignificant changes of plasma appearance rate of NE during our desipramine and nitroprusside infusions.

Adult↗
PubMed1990

Determination of benzo[a]pyrene diol epoxide-DNA adducts in white blood cell DNA from coke-oven workers: the impact of smoking.

We have undertaken a study among coke-oven workers to test the feasibility of an enzyme-linked immunosorbent assay with anti-trans-7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydro-benzo[a]pyrene- DNA antibodies for monitoring occupational exposure to polycyclic aromatic hydrocarbons (PAH). Coke-oven workers are occupationally exposed to relatively high levels of PAH and are at increased risk for lung cancer. Three blood samples were collected from each of the 56 coke-oven workers exposed to PAH and 44 unexposed workers employed in a steel-rolling factory of the same plant. In addition, PAH levels were measured in ambient air by personal sampling, and the excretion of 1-hydroxypyrene in urine was also measured on 3 consecutive working days. All participants were interviewed regarding working conditions, personal hygiene, and smoking habits. The results showed that the coke-oven workers were exposed to substantial concentrations of atmospheric PAH (1-186 micrograms/m3), including benzo[a]pyrene (0.1-7.8 micrograms/m3) and pyrene (0.6-23.6 micrograms/m3). Both benzo[a]pyrene and pyrene were shown to be representative for the whole group of PAH. Forty-seven percent of the coke-oven workers had detectable levels of PAH-DNA adducts in their white blood cells, compared with 30% of the controls. In both groups, smokers had significantly higher levels of PAH-DNA adducts than did nonsmokers. At one site, we found the correlation positive between DNA adducts and the duration of exposure (r = .47, P = .005). Generally, the correlation was not significant between PAH-DNA adducts in blood and the concentration of PAH in the air and 1-hydroxypyrene in urine.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed1990

Polycyclic aromatic hydrocarbon-DNA adducts in lung tissue from lung cancer patients.

In an attempt to probe for polycyclic aromatic hydrocarbon (PAH)-DNA adducts in human subjects resulting from smoking (or other chronic environmental exposure), lung tissue and lung tumours were obtained from patients hospitalized for lung cancer. DNA was isolated from the tissue samples and examined both in an ELISA using a polyclonal antibody against (+/-)trans-7,8-dihydroxy-anti-9,10-epoxy-7,8,9,10- tetrahydrobenzo[a]pyrene (BPDE)-DNA as well as by the nuclease P1-mediated modification of the 32P-post-labelling technique. The ELISA results showed BPDE-DNA antigenicity in lung DNA from 6 out of 21 patients, and adduct levels ranged from 2 to 134 adducts per 10(8) nucleotides. For all 21 patients, the autoradiographs of chromatograms of 32P-postlabelled digests of DNA from non-tumorous lung tissue showed a strong diagonal radioactive zone (DRZ). This DRZ was generally absent in tumorous tissue. DNA samples that were positive in the ELISA contained a dominant spot within the DRZ that co-chromatographed with the major BPDE-DNA adduct (BPDE-dG). The quantities of the BPDE-dG spots ranged from 2.1 to 42 adducts in 10(9) nucleotides. These values were lower than the levels found in the ELISA but correlated well with the ELISA results (Kendall W = 0.97; P = 0.00). The levels of the DRZ adducts ranged from 1.9 to 34 adducts in 10(8) nucleotides. Correlations between smoking and DNA adduct levels were poor because of the small number of current smokers (n = 13). However, smokers of filter cigarettes had significantly lower DNA adduct levels compared with smokers of cigarettes without a filter (P = 0.02 by Fischer's exact test).

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed1989

Synthesis of heterocyclic N-acetoxyarylamines and their reactivity with DNA.

2-Acetoxyamino-5-phenylpyridine and 2-acetoxyamino-3-methyl-5-phenylpyridine, being proposed ultimate carcinogens of the heterocyclic aromatic amines 2-amino-5-phenylpyridine (APP) and 2-amino-3-methyl-5-phenylpyridine (AMPP), respectively, were synthesized, crystallized and characterized. Using the 32P-postlabelling technique, we show that the total amount of adducts found in DNA after reaction with these N-acetoxyarylamines is at least 30- and 450-fold higher than in DNA reacted with equimolar amounts of the proposed proximate carcinogens 2-hydroxyamino-5-phenylpyridine and 2-hydroxyamino-3-methyl-5-phenylpyridine, respectively. These results support a postulated activation mechanism, in which N-acetoxyarylamines are the ultimate reactive species responsible for DNA modification by carcinogenic aromatic amines in vivo. The possibility to obtain the reactive 0-acetyl derivatives of APP and AMPP in crystalline form makes them unique model compounds for studies on the interaction of ultimate carcinogens of aromatic amines with DNA.

Amines↗
PubMed1989

Stimulation of norepinephrine release by peripheral presynaptic beta-adrenoceptors.

Increases in plasma norepinephrine (NE) concentration induced by beta-agonist infusion have been taken as evidence for the existence of peripheral presynaptic beta-adrenoceptors, facilitating NE release. Concomitant hemodynamic changes, however, could invoke reflex mechanisms and thus hamper the interpretation of the results. We studied the presence of peripheral presynaptic beta-adrenoceptors by giving intra-arterial infusions of EPI in the forearm before and during uptake inhibition, and the effects of systemic infusions of very low-dose epinephrine (EPI) and isoproterenol (ISO) on hemodynamics and arterial and venous plasma NE concentrations. An i.a. infusion of EPI, 0.1 ng.kg-1.min-1, increased the net overflow of NE from 0.3 +/- 1.0 to 5.4 +/- 1.8 pmol.min-1 (M +/- SEM, p less than 0.05) and raised the calculated arterial plasma EPI concentration to 0.92 +/- 0.22 nmol.l-1. The uptake inhibition increased the net overflow of NE to 15.4 +/- 2.4 pmol.min-1 and during addition of EPI, 0.1 ng.kg-1.min-1, it further increased to 23.0 +/- 4.1 pmol.min-1 (p less than 0.05), while it decreased during addition of an effective beta-blocking dose of propranolol, 50 ng.kg-1.min-1 i.a., to 18.2 +/- 4.1 pmol.min-1 (n.s.). Systemic infusions of EPI and ISO increased blood pressure, heart rate, and forearm blood flow before significant changes in arterial or venous plasma NE concentrations were found. It is concluded that the increases in net NE overflow from the forearm during local EPI infusions indicate the presence of peripheral presynaptic beta-adrenoceptors which are responsive to physiologic concentrations of EPI. Systemic infusions of EPI or ISO elicit hemodynamic effects, and thus may invoke reflex mechanisms, before an influence on arterial or venous plasma NE concentration is found.

Adult↗
PubMed1988

Haemodynamic effects of physiological concentrations of circulating noradrenaline in man.

1. To define the role of circulating noradrenaline in cardiovascular regulation, threshold concentrations for haemodynamic effects were determined in arterial and venous plasma of eight healthy volunteers. 2. Five doses of noradrenaline, 0-54 ng min-1 kg-1, were infused intravenously in random order and single-blind for 15 min per dose. Changes in intra-arterial blood pressure, heart rate, forearm blood flow and forearm vascular resistance were determined, and plasma noradrenaline was measured in arterial and venous blood samples. 3. Significant increases in systolic and diastolic blood pressure were found at arterial and venous plasma noradrenaline concentrations (means +/- SEM) of 3.00 +/- 0.23 and 1.35 +/- 0.12 nmol/l, respectively. A significant decrease in heart rate was found at arterial and venous plasma noradrenaline concentrations of 8.99 +/- 0.69 and 3.09 +/- 0.60 nmol/l, respectively. The lower doses of noradrenaline tended to increase forearm blood flow and to decrease forearm vascular resistance, whereas the higher doses had no consistent effect on forearm haemodynamics. 4. During the noradrenaline infusions 73 +/- 5% of the increase in arterial plasma noradrenaline concentration was extracted in the forearm. 5. The venous plasma noradrenaline threshold concentration was found to be much lower than previously reported. It is concluded that arterial and venous plasma noradrenaline concentrations which are readily encountered in physiological circumstances elicit haemodynamic effects.

Adult↗
PubMed1988

Binding efficiency of antibodies to DNA modified with aromatic amines and polycyclic aromatic hydrocarbons: implications for quantification of carcinogen-DNA adducts in vivo.

Antibodies raised against the bovine serum albumin conjugates of N-(guanosin-8-yl)-N-2-acetylaminofluorene (Guo-8-AAF), the imidazole ring-opened form of N-(guanosin-8-yl)-2-aminofluorene (roGuo-8-AF) and the methylated bovine serum albumin complex of DNA modified with (+/-)trans-7,8-dihydroxy-anti-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyre ne (BPDE) have been employed in a highly sensitive enzyme-linked immunosorbent assay (ELISA) to determine their affinity for DNA modified with the corresponding carcinogens at various levels of modification. All antibodies recognized highly modified DNA more efficiently than DNA of low modification. This property, which may be common to all antibodies raised against carcinogen-DNA adducts, has to be taken into account when these antibodies are used to quantify carcinogen-DNA adducts in biological samples. Appropriate DNA preparations of low modification have to be used as reference compounds in immunoassays to allow reliable quantification of adduct levels in DNA from animals and human cells.

2-Acetylaminofluorene↗
PubMed1987

The binding efficiency of polyclonal and monoclonal antibodies to DNA modified with benzo[a]pyrene diol epoxide is dependent on the level of modification. Implications for quantitation of benzo[a]pyrene-DNA adducts in vivo.

A number of polyclonal antibodies specific for DNA modified with (+/-)trans-7,8-dihydroxy-anti-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyre ne (BPDE) were obtained from the sera of New Zealand white rabbits immunized with BPDE-DNA, complexed with methylated bovine serum albumin (mBSA). Monoclonal antibodies were developed by fusion of mouse myeloma cells with spleen cells isolated from BALB/c mice immunized with the same complex of BPDE-DNA and mBSA. These antibodies have been characterized for specificity in a highly sensitive, enzyme-linked immunosorbent assay (ELISA). All antibodies showed a very high affinity for single-stranded BPDE-DNA, but had lower affinity towards native BPDE-DNA. The affinity for the free mononucleoside BPDE-dG was at least 100-fold lower than that for BPDE-DNA, and no affinity was detected for BP tetrols or DNA modified with N-acetoxy-N-acetyl-2-aminofluorene. A high cross reactivity was observed with DNA modified with (+/-)-trans-1,2-dihydroxy-anti-3,4-epoxy-1,2,3,4-tetrahydrochrysene++ +. Using five different antibodies, monoclonal or polyclonal, we observed that the antibody affinity for BPDE-DNA was dependent on the level of modification; in the competitive ELISA as little as 4 fmol BPDE-DNA (50 pmol/micrograms) was sufficient for 50% inhibition with our best antisera, but 17 fmol of the adduct was required when [3H]BPDE-DNA of low modification (1-10 fmol/micrograms) was used as inhibitor. When samples of [3H]BP-DNA isolated from the livers of mice, treated i.p. with different doses of [3H]BP were examined by competitive ELISA and calibrated with [3H]BPDE-DNA of low modification (1-10 fmol/micrograms), binding values calculated from the immunoassay were in good agreement with those obtained from radioactivity measurements. In contrast, when this DNA was quantitated in competitive ELISA using highly modified BPDE-DNA as standards, values by ELISA were 20-40% of those obtained by radioactivity. These results indicate that the use of serially diluted BPDE-DNA of high modification as standard competitor in the ELISA will lead to erroneous results in the measurement of adducts in DNAs modified to a low extent (biological samples). The property of antisera specific for BP-DNA, recognizing highly modified DNA more efficiently than DNA modified to a low extent, may be common to all antisera elicited against highly modified DNA immunogens. Therefore we conclude that antibody affinity must be tested also with DNA samples of low modification, obtained either in vitro or in vivo.

2-Acetylaminofluorene↗
PubMed1986

The biological activity of single-stranded phi X174 DNA, modified by N-hydroxy-2-aminofluorene, is inhibited by guanine imidazole ring-opening of the major, non-lethal aminofluorene-DNA adduct.

The major aminofluorene-DNA derivative, found in the liver of rats after administration of the hepatocarcinogen N-acetyl-2-aminofluorene and identified as N-(deoxyguanosin-8-yl)-2-aminofluorene (dGuo-C8-AF), was introduced in different amounts in single-stranded phi X174 DNA by reacting the DNA with tritium labeled N-hydroxy-2-aminofluorene. The modified DNA was subsequently incubated in 0.1 M NaOH at 37 degrees C for increasing periods of time to convert the dGuo-C8-AF residues into their guanine imidazole ring-opened forms. The degree of conversion was determined by measuring the amount of residual N-(guanin-8-yl)-2-aminofluorene in trifluoroacetic acid hydrolyzates of the alkali-treated DNA by h.p.l.c. In addition, the effect of ring opening on the biological activity of the DNA was monitored by transfecting the DNA to Escherichia coli wild-type spheroplasts. The results indicate that the major aminofluorene-DNA adduct formed initially, which contributes little to inactivation, becomes lethal when its guanine imidazole ring is opened.

Bacteriophage phi X 174↗
PubMed1985

Hybridization of N-acetoxy-N-acetyl-2-aminofluorene-labelled RNA to Q-banded metaphase chromosomes.

This paper describes improvements of a recently developed immunocytochemical method for the detection of specific polynucleotide sequences within chromosomes, as well as conditions by which this method can be combined with chromosome banding. The immunocytochemical method involves modification of polynucleotide probes with N-acetoxy-N-acetyl-2-aminofluorene (AAAF)2), and hybridization of the modified probes with metaphase chromosomes; the hybrids are made visible immunocytochemically by means of an antiserum which recognizes AAAF-induced polynucleotide modifications. We have sorted out conditions which allow a high sensitivity of hybrid detection by the above procedure, in combination with chromosome banding. The best results are obtained if the ABC-technique is used for the visualization of the hybrids; the lower limit of detection is estimated to be a sequence of about 7000 nucleotides. The method can be combined with Q-banding of chromosomes, if this is performed not more than 1 day prior to hybridization, and if excitation of the Q-banded chromosomes is kept to a minimum.

2-Acetylaminofluorene↗
PubMed1985

By-pass of the major aminofluorene-DNA adduct during in vivo replication of single- and double-stranded phi X174 DNA treated with N-hydroxy-2-aminofluorene.

To examine the effects of aminofluorene-DNA adduct formation on the biological activity of DNA, single-stranded (ss) phi X174 DNA and phi X174 replicative form (RF) DNA were modified to different extents with 3H-labeled N-hydroxy-2-aminofluorene and subsequently transfected to Escherichia coli spheroplasts with different repair capabilities. When the fraction of active ss phi X174 DNA molecules was measured as a function of the mean number of adducts per molecule, exponential survival curves were obtained from which it could be deduced that in wild-type, uvrA- and recA- cells at least 86%, and in uvrC- cells at least 82% of the introduced adducts do not cause inactivation. In the case of RF DNA the survival curves are non-exponential, but they nevertheless show that an exceptionally high number of adducts per RF molecule must be introduced to destroy its biological activity. On average 52 adducts per RF molecule were needed to reduce the survival to 37%, irrespective of whether wild-type, uvrA- or recA- cells were used. On the other hand, the survival of the uvrC- cells was considerably lower, but even in these cells a majority of the adducts is not lethal. By h.p.l.c. analysis of the modified DNA after hydrolysis with trifluoroacetic acid, 81 and 84% of the adducts in ss- and RF DNA, respectively, could be identified as N-(guanin-8-yl)-2-aminofluorene. The results strongly indicate that this type of major modification product is very frequently by-passed during replication of both single- and double-stranded DNA. The results together with the data obtained by sucrose gradient analysis both before and after an alkali treatment and those obtained by h.p.l.c. analysis suggest that inactivation of ssDNA is mainly due to minor modifications such as secondary lesions consisting of chain breaks and alkali-labile sites together with unidentified interaction products.

Bacteriophage phi X 174↗
PubMed1985

Immunohistochemical localization of O6-ethyldeoxyguanosine and deoxyguanosin-8-yl-(acetyl)aminofluorene in liver sections of rats treated with diethylnitrosamine, ethylnitrosourea or N-acetylaminofluorene.

Antibodies raised in rabbits against the bovine serum albumin conjugates of O6-ethylguanosine (O6-EtGuo) and N-(guanosin-8-yl)-N-acetyl-2-aminofluorene (Guo-8-AAF) have been used in a double peroxidase-antiperoxidase staining assay to visualize the localization of DNA-O6-ethyldeoxyguanosine (O6-EtdGuo) and some of the interaction products of N-acetyl-2-aminofluorene (AAF) with DNA guanine in liver sections of rats treated with diethylnitrosamine (DEN), ethylnitrosourea (ENU), or AAF respectively. O6-EtdGuo could be detected in nuclei of parenchymal cells after injection of DEN (12-50 mg/kg) or ENU (140 mg/kg). Clear time and dose dependencies were observed. The lowest dose of DEN which, at 5 h after injection, resulted in immunohistochemically detectable levels of O6-EtdGuo, was 12 mg/kg; 5 h after 6 mg/kg no consistent difference between treated and untreated rats could be observed. A striking heterogeneity in staining pattern was observed after DEN: centrilobular regions were stained much more than peripheral zones. At 7 days after a single DEN injection of 50 mg/kg small rims of significantly stained hepatocytes could still be observed around the central veins. No heterogeneity of staining pattern was observed 2 h after ENU. ENU, in contrast with DEN, also resulted in a significant staining of nonparenchymal cells. At 24 h after ENU no significant staining of hepatocytes could be detected, but positive staining was still present in bile duct cells, vascular endothelial cells and sinusoidal cells. The results indicate a detection level of approximately 5 mumol O6-EtdGuo/mol DNA-P, i.e., 5 X 10(4) O6-EtdGuo residues per diploid genome. Using the anti-Guo-8-AAF antiserum, positive results were obtained 6 days after a single AAF dose of 0.5-10 mg/kg, corresponding to a detection limit of less than or equal to 0.4 mumol dGuo-8-(A)AF/mol DNA-P. Staining was rather homogenously distributed over the liver lobules. Persistency of the AAF-DNA interaction products was investigated both after 10 and 2 mg/kg AAF. Increased nuclear staining could be observed up to 8 weeks after 10 mg/kg and 4 weeks after 2 mg/kg.

2-Acetylaminofluorene↗
PubMed1984

Quantitation of carcinogen-DNA adducts by a standardized high-sensitive enzyme immunoassay.

A highly sensitive competitive enzyme immunoassay has been developed, allowing accurate determination of DNA containing the adducts N-(deoxyguanosin-8-yl)-N-acetyl-2-amino-fluorene, N-(deoxyguanosin-8-yl)-2-aminofluorene, 1-[6-(2,5-diamino-4-oxopyrimidinyl-N6-deoxyriboside)]-3-(2-fluo renyl)urea or trans-(7R)-N2-[10-(7 beta,8 alpha,9 alpha-trihydroxy-7,8, 9,10-tetrahydrobenzo[a]pyren)yl]deoxyguanosine. Standard amounts of the carcinogen-modified DNA preparations (25 fmol/500 ng) were coated on the wells of microtitre plates. Various amounts of the modified DNA preparations were used as inhibitors and added before binding of the antibodies (dilution 1:10(6). As second antibody, goat anti-rabbit IgG coupled to alkaline phosphatase was used. The amount of enzyme was determined with 4-methylumbelliferyl phosphate as substrate (Van der Laken et al., 1982). The 50% inhibition values of the standard curves are in the range of 2-16 fmol for the enzyme immunoassays. It is possible to add up to 50 micrograms of unknown DNA to the wells, allowing for comparison with the same quantity of modified DNA. This extends the limit of detection to 1-6 adducts per 10(8) nucleotides. The sensitivity of the assay seems sufficient to demonstrate exposure of humans to known chemical carcinogens.

Animals↗
PubMed1982

Measurement of O6-ethyldeoxyguanosine and N-(deoxyguanosin-8-yl)-N-acetyl-2-aminofluorene in DNA by high-sensitive enzyme immunoassays.

Antibodies raised in rabbits against the bovine serum albumin conjugates of O6-ethylguanosine and N-(guanosin-8-yl)-N-acetyl-2-aminofluorene have been used to develop a high-sensitive enzyme-linked immunosorbent assay (HS-ELISA) for the quantification of adducts in DNA modified by ethylating agents and N-acetyl-2-aminofluorene. Linear dose-response relations were obtained in the non-competitive HS-ELISA between 0.5 fmol and 50 fmol O6-ethyldeoxy-guanosine per 2.8 microgram DNA, and between 0.1 fmol and 20 fmol N-(deoxyguanosin-8-yl)-N-acetyl-2-aminofluorene per 0.8 microgram DNA. The sensitivity of an ultrasensitive radioimmunoassay was in the same order of magnitude. Modification levels as low as 0.1 mumol of adduct/mol DNA-nucleotides (1: 10(7)) can be detected by each assay.

2-Acetylaminofluorene↗
PubMed1982

Immunological detection and quantification of the reaction products of 2-acetylaminofluorene with guanine in DNA.

Rabbits were immunized with N-(guanosin-8-yl)-N-acetyl-2-aminofluorene bound to bovine serum albumin. The presence of specific antibodies was determined in a radioimmunoassay by competing N-([5'-3H]-guanosin-8-yl)-N-acetyl-2-aminofluorene (specific radioactivity, 25 Ci/mmol) as tracer against various carcinogen-modified and normal DNA components. Highly specific antibodies were obtained (affinity constant, 6.0 X 10(9) l/mol) and have been employed in a sensitive radioimmunoassay to determine N-(deoxyguanosin-8-yl)-N-acetyl-2-aminofluorene directly in enzymatic hydrolysates of DNA modified with N-acetoxy-N-acetyl-2-aminofluorene. In a similar fashion, the modified nucleoside could be detected in hydrolysed rat liver DNA following administration of N-acetyl-2-aminofluorene, with a detection limit of one carcinogen-modified deoxyguanosine moiety per 10(6) deoxynucleotides in 150 micrograms of DNA.

2-Acetylaminofluorene↗