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Puviani A, Lodi A, Tassinari B, Ottolenghi C, Ganzerli S, Ricci D, Pazzi P, Morsiani E. Morphological and Functional Evaluation of Isolated Rat Hepatocytes in three Dimensional Culture Systems. Int J Artif Organs 2018. [DOI: 10.1177/039139889902201112] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Various three-dimensional configurations, such as polyester tissue and woven-nonwoven, hydrophilic polyester fabric, either collagen-coated or uncoated, were investigated as potential scaffold for hepatocyte culture, in view of their use in bioreactors for hybrid liver support systems. Attachment, morphology and ultrastructure of primary adult rat hepatocytes were evaluated, as well as urea production and ammonium detoxification during a 24h incubation period in serum-free tissue culture medium. As control, hepatocytes were also plated onto collagen-coated dextran microcarriers and on plastic petri dishes, either collagen-coated or uncoated. In all the three-dimensional cultures, hepatocytes appeared morphologically intact without any statistically significant difference in metabolic activity. Collagen-coating did not influence cell attachment to polyester substrates, whereas woven-nonwoven hydrophilic polyester fabric may offer some potential advantages as three-dimensional system for hepatocyte culture in hybrid liver support systems.
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Affiliation(s)
- A.C. Puviani
- Departments of Biology, University of Ferrara and Sant'Anna Hospital, Ferrara - Italy
| | - A. Lodi
- Departments of Biology, University of Ferrara and Sant'Anna Hospital, Ferrara - Italy
| | - B. Tassinari
- Departments of Biology, University of Ferrara and Sant'Anna Hospital, Ferrara - Italy
| | - C. Ottolenghi
- Departments of Biology, University of Ferrara and Sant'Anna Hospital, Ferrara - Italy
| | - S. Ganzerli
- Departments of Biology, University of Ferrara and Sant'Anna Hospital, Ferrara - Italy
| | - D. Ricci
- Departments of Human Anatomy, University of Ferrara and Sant'Anna Hospital, Ferrara - Italy
| | - P. Pazzi
- Departments of Gastroenterology and University of Ferrara and Sant'Anna Hospital, Ferrara - Italy
| | - E. Morsiani
- Departments of Surgery, University of Ferrara and Sant'Anna Hospital, Ferrara - Italy
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Transcriptomic characterization of bovine primary cultured hepatocytes; a cross-comparison with a bovine liver and the Madin-Darby bovine kidney cells. Res Vet Sci 2017; 113:40-49. [PMID: 28863307 DOI: 10.1016/j.rvsc.2017.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 07/07/2017] [Accepted: 08/07/2017] [Indexed: 02/06/2023]
Abstract
Bovine primary cultured hepatocytes (CHs) are widely used in vitro models for liver toxicity testing. However, little is known about their whole-transcriptome profile and its resemblance to the normal liver tissue. In the present study, we profiled - by microarray - the whole-transcriptome of bovine CHs (n=4) and compared it with the transcriptomic landscape of control liver samples (n=8), as well the Madin-Darby bovine kidney (MDBK) cells (n=4). Compared with liver tissue, the bovine CHs relatively expressed (fold change >2, P<0.05) about 2155 and 2073 transcripts at a lower and higher abundance, respectively. Of those expressed at a lower abundance, many were drug biotransformation enzyme-coding genes, such as the cytochrome P450 family (CYPs), sulfotransferases, methyltransferases, and glutathione S-transferases. Also, several drug transporters and solute carriers were expressed at a lower abundance in bovine CHs. 'Drug metabolism', 'PPAR signaling', and 'metabolism of xenobiotics by CYPs' were among the most negatively-enriched pathways in bovine CHs compared with liver. A qPCR cross-validation using 8 selected genes evidenced a high correlation (r=0.95, P=0.001) with the corresponding microarray results. Although from a kidney origin, and albeit to a lower extent compared to bovine CHs, the MDBK cells showed a basal expression of many CYP-coding genes. Our study provides a whole-transcriptome-based evidence for the bovine CHs and hepatic tissue resemblance. Overall, the bovine CHs' transcriptomic profile might render it unreliable as an in vitro model to study drug metabolism.
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Primary hepatocytes as an useful bioassay to characterize metabolism and bioactivity of illicit steroids in cattle. Toxicol In Vitro 2012; 26:1224-32. [DOI: 10.1016/j.tiv.2012.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 06/04/2012] [Accepted: 06/08/2012] [Indexed: 12/28/2022]
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Wu H, Li L, Shen J, Wang Y, Liu K, Zhang S. In vitro metabolism of cyadox in rat, chicken and swine using ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry. J Pharm Biomed Anal 2012; 67-68:175-85. [DOI: 10.1016/j.jpba.2012.04.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2012] [Revised: 04/01/2012] [Accepted: 04/04/2012] [Indexed: 11/29/2022]
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Montesissa C, Capolongo F, Santi A, Biancotto G, Dacasto M. Metabolism of tilmicosin by rabbit liver microsomes and hepatocytes. Vet J 2004; 167:87-94. [PMID: 14623156 DOI: 10.1016/s1090-0233(03)00077-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We investigated tilmicosin (TIM) metabolism, at 25, 50 or 100 microM, in cultures of primary hepatocytes from rabbits bred commercially for food and in liver microsomes prepared from both untreated and rifampicin (RIF)-treated rabbits. RIF is a well-known cytochrome P4503A (CYP 3A) inducer in rabbits and most macrolides are known to be substrates of CYP 3A. No peaks in addition to those of the cis and trans forms of TIM were observed by high performance liquid chromatography (HPLC) in extracts of microsomes from untreated rabbits. When TIM was incubated with induced microsomes, at least two peaks were found by HPLC and an additional peak, eluting at shorter retention time was isolated from hepatocytes incubated for 24h with the macrolide. The structures of the metabolites were then estimated by liquid chromatography-mass spectrometry (LC-MS) in concentrated extracts from induced microsomes. Five metabolites were separated and putatively identified: cis and trans demethylated tilmicosin, tilmicosin N-oxide and cis and trans tilmicosin epoxide. The overall amount of metabolites produced in vitro using livers of untreated and RIF treated rabbits was very low, has also been observed in vivo and in vitro in cattle, chickens and pigs.
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Affiliation(s)
- C Montesissa
- Dipartimento di Sanità pubblica Patologia comparata ed Igiene veterinaria, Agripolis, I-35020 Legnaro, Padua, Italy.
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Montesissa C, Huveneers MB, Hoogenboom LA, Amorena M, De Liguoro M, Lucisano A. The oxidative metabolism of aldicarb in pigs: in vivo-in vitro comparison. DRUG METABOLISM AND DRUG INTERACTIONS 2002; 11:127-38. [PMID: 12369596 DOI: 10.1515/dmdi.1994.11.2.127] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Aldicarb was administered (1 mg/kg b.w.) to four female pigs and the kinetics of its major oxidized metabolites (sulfoxide and sulfone) was followed for 6 hours. The in vitro transformations of the carbamate pesticide into these two still active metabolites were also investigated in hepatocytes and in microsomes from pig livers. In all cases, aldicarb was quickly oxidized to the sulfoxide (major metabolite) and only a minor quantity of sulfone was produced. The in vivo toxic symptomatology was related to the peak serum concentration of sulfoxide, suggesting that this metabolite is principally responsible for the aldicarb toxicity. Selective in vitro inhibition of flavin-containing and cytochrome P-450 monooxygenases confirmed that the former enzymes catalyze mainly sulfoxide production whereas the latter that of sulfone.
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Affiliation(s)
- C Montesissa
- Institute of Veterinary Pharmacology, Pharmacokinetics and Toxicology, University of Bologna, Italy
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Eeckhoutte C, Albo AG, Carletti M, Giaccherino AR, Galtier P, Nebbia C, Dacasto M. Time-dependent variations of drug-metabolising enzyme activities (DMEs) in primary cultures of rabbit hepatocytes. Toxicol In Vitro 2002; 16:375-82. [PMID: 12110275 DOI: 10.1016/s0887-2333(02)00018-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In the present study, time-dependent variations of drug-metabolising enzyme activities (DMEs) in primary cultures of rabbit hepatocytes, a species of economic importance in Mediterranean countries, were investigated. Cross-bred rabbits were anesthetised and their livers perfused in situ by a two-step collagenase technique; cells suspensions were filtered, seeded in collagen-coated dishes and cultivated at 37 degrees C in a controlled atmosphere for 24 and 72 h. Cytochrome P450 and b(5) contents as well as the catalytic activity of some P450-dependent monooxygenases were measured in subcellular fractions obtained by differential ultracentrifugation; microsomal proteins were also subjected to immunoblotting, using antibodies to rat P4501A, 2B, 2E1 and 3A isoforms. The activity of some microsomal hydrolytic enzymes was also determined. As regards conjugative enzymes, glutathione content and activities of glutathione S-transferase, uridindiphosphoglucuronosyl-transferase, acetyl-transferase and 1,2-epoxibuthane glutathione transferase were assayed. An overall reduction of the catalytic activity was observed 72 h after plating, reaching in certain instances the level of statistical significance. On the whole, our data confirm those previously reported with hepatocytes obtained from other species; however, the evidence that DMEs were still measurable after 72 h supports the usefulness of this in vitro method for drug metabolism studies in the rabbit as well.
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Affiliation(s)
- C Eeckhoutte
- Institut Nationale de la Recherche Agronomique, Laboratoire de Pharmacologie et Toxicologie, UR66, 180 chemin de Tournefeuille, St. Martin du Touch, BP 3, 31931 Toulouse cedex, France
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Morsiani E, Brogli M, Galavotti D, Bellini T, Ricci D, Pazzi P, Puviani AC. Long-term expression of highly differentiated functions by isolated porcine hepatocytes perfused in a radial-flow bioreactor. Artif Organs 2001; 25:740-8. [PMID: 11722353 DOI: 10.1046/j.1525-1594.2001.06669.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
To overcome the limitations of standard hollow-fiber module in ensuring efficient cell perfusion and long-term expression of highly differentiated hepatocyte functions, we developed a novel bioreactor in which a three-dimensional hepatocyte culture system was perfused in radial-flow geometry. Isolated porcine hepatocytes were cultured for 2 weeks in recirculating serum-free tissue culture medium, in which NH4Cl and lidocaine were repeatedly added, and ammonia removal, urea synthesis, monoethylglycinexylide (MEGX) production, albumin secretion, Po2, Pco2, O2 consumption, and pH were measured thereafter. During the whole duration of the study, ammonia removal was paralleled by urea production, while MEGX concentration was constantly increased. Our results indicated that hepatocytes remained differentiated and metabolically active throughout the duration of the study. The radial-flow bioreactor allowed physiological contact between recirculating fluid and cells by equalizing the concentration of the perfusing components, including O2, throughout the module, suggesting a potential use of this configuration for extracorporeal liver support.
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Affiliation(s)
- E Morsiani
- Department of Surgery, University of Ferrara School of Medicine and Sant'Anna Hospital, Corso Giovecca 203, I-44100 Ferrara, Italy.
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Behnia K, Bhatia S, Jastromb N, Balis U, Sullivan S, Yarmush M, Toner M. Xenobiotic metabolism by cultured primary porcine hepatocytes. TISSUE ENGINEERING 2000; 6:467-79. [PMID: 11074934 DOI: 10.1089/107632700750022125] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Considering the large yield of viable cells comparable to human liver, primary porcine hepatocytes offer a valuable resource for constructing a bioartificial liver device. In this study, the ability of cultured primary porcine hepatocytes to detoxify xenobiotics has been examined using various known substrates of cytochrome P450 isoenzymes and UDP-glucuronosyltransferases. Present investigation demonstrated the stability of the isoenzymes responsible for the metabolism of diazepam in native state and stabilization of other isoenzymes, as judged by ethoxycoumarin o-dealkylase (ECOD), ethoxyresorufin o-dealkylase (EROD), benzyloxyresorufin o-dealkylase (BROD), and pentoxyresorufin o-dealkylase (PROD) activities following induction in culture environment, for a period of 8 days. Resorufin O-dealkylase activities were found to be the most unstable and deteriorated within first 5 days in culture. These activities were restored following induction with 3-methylcholanthrene (3-MC) or sodium phenobarbital (PB) to 20-fold of 1 activity for EROD, and 60 and 174% of day 1 activity for PROD and BROD on day 8, respectively. Metabolism of methoxyresorufin was most strikingly increased following induction with 3-MC to approximately 60-fold of day 1 activity, on day 8. UDP-glucuronosyltransferase-dependent glucuronidation of phenol red, however, stayed intact during the course of our study without induction. Our study indicated that porcine hepatocytes in vitro maintain many important liver-specific functions including detoxification (steady state and inducibility).
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Affiliation(s)
- K Behnia
- Centre for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School and Shriners Hospitals for Children, Boston, Massachusetts 02114, USA
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Kuilman ME, Maas RF, Woutersen-van Nijnanten FM, Fink-Gremmels J. Inhibition of aflatoxin M1 production by bovine hepatocytes after intervention with oltipraz. Vet Q 2000; 22:30-5. [PMID: 10682385 DOI: 10.1080/01652176.2000.9695020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022] Open
Abstract
It is well known that cattle ingesting aflatoxin B1 contaminated feed commodities excrete aflatoxin M1 into their milk. As aflatoxin M1 originates from hepatic metabolism, measures to prevent aflatoxin M1 formation need to be directed to either the immobilization of aflatoxin B1 in the gastrointestinal tract or the modification of hepatic metabolism of aflatoxin B1. Here we studied the influence of oltipraz and a second dithiolthione, (1,2) dithiolo (4,3-c)-1,2-dithiole-3,6 dithione (DDD) on bovine hepatic aflatoxin B1 biotransformation. Oltipraz inhibited aflatoxin B1 metabolism as no aflatoxin M1 and no aflatoxin B1-dihydrodiol, the second metabolite found in bovine hepatocytes, was formed. DDD did not significantly inhibit aflatoxin B1 metabolism. It could be demonstrated that the inhibition of aflatoxin B1 metabolism was due to the inhibition of several cytochrome P450 enzyme activities by oltipraz. In contrast, DDD inhibited only ethoxyresorufin O-deethylation activity. These findings suggest a high efficacy of oltipraz in inhibiting aflatoxin M1 contamination of milk from dairy cows exposed to aflatoxin B1 contaminated feeds.
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Affiliation(s)
- M E Kuilman
- National Institute of Public Health and the Environment Center for Substances and Risk Assessment, The Netherlands.
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Van Puymbroeck M, Kuilman ME, Maas RF, Witkamp RF, Leyssens L, Van Miert AS, Hendriks L, Vanderzande D, Adriaensens P, Jacobs MP, Raus J. 17alpha-ethyl-5beta-estrane-3alpha, 17beta-diol, a biological marker for the abuse of norethandrolone and ethylestrenol in slaughter cattle. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1999; 728:217-32. [PMID: 10406207 DOI: 10.1016/s0378-4347(99)00091-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The metabolism of the illegal growth promoter ethylestrenol (EES) was evaluated in bovine liver cells and subcellular fractions of bovine liver preparations. Incubations with bovine microsomal preparations revealed that EES is extensively biotransformed into norethandrolone (NE), another illegal growth promoter. Furthermore, incubations of monolayer cultures of hepatocytes with NE indicated that NE itself is rapidly reduced to 17alpha-ethyl-5beta-estrane-3alpha, 17beta-diol (EED). In vivo tests confirmed that, after administration of either EES or NE, EED is excreted as a major metabolite. Therefore, it was concluded that, both in urine and faeces samples, EED can be used as a biological marker for the illegal use of EES and/or NE. Moreover, by monitoring EED in urine or faeces samples, the detection period after NE administration is significantly prolonged. These findings were further confirmed by three cases of norethandrolone abuse in a routine screening program for forbidden growth promoters.
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Affiliation(s)
- M Van Puymbroeck
- Dr. L. Willems-Instituut, Department of Drug and Residue Analysis, Limburgs Universitair Centrum, Diepenbeek, Belgium
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Swales NJ, Caldwell J. Phase 1 and 2 Metabolism in Freshly Isolated Hepatocytes and Subcellular Fractions from Rat, Mouse, Chicken and Ox Livers. ACTA ACUST UNITED AC 1999. [DOI: 10.1002/(sici)1096-9063(199703)49:3<291::aid-ps505>3.0.co;2-i] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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13
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Huveneers-Oorsprong M, Hoogenboom L, Kuiper H. The use of the MTT test for determining the cytotoxicity of veterinary drugs in pig hepatocytes. Toxicol In Vitro 1997; 11:385-92. [DOI: 10.1016/s0887-2333(97)00022-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/1997] [Indexed: 10/17/2022]
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Alsemgeest SP, van 't Klooster GA, van Miert AS, Hulskamp-Koch CK, Gruys E. Primary bovine hepatocytes in the study of cytokine induced acute-phase protein secretion in vitro. Vet Immunol Immunopathol 1996; 53:179-84. [PMID: 8941979 DOI: 10.1016/0165-2427(96)05602-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
To investigate the utility of primary cultures of bovine hepatocytes for compartmentalized acute phase protein studies the secretion of serum amyloid-A (SAA) and haptoglobin (Hp) was measured after stimulation by pro-inflammatory cytokines (recombinant human IL-6 (rhIL-6) and recombinant human tumour necrosis factor-alpha (rhTNF-alpha)). During the incubation period of the experiment, the SAA and Hp secretion into the culture medium increased (P < 0.05). SAA concentrations showed an additional increase following treatment with each of the cytokines (P < 0.01). Hp concentrations remained unchanged, whereas incubation with a combination of both resulted in a significant increase of the medium concentration of both SAA (P < 0.01) and Hp (P < 0.05). From these findings it is concluded that primary bovine hepatocytes can be used for in vitro studies on acute-phase protein secretion.
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Affiliation(s)
- S P Alsemgeest
- Department of Pathology, Faculty of Veterinary Medicine, Utrecht University, The Netherlands
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15
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Montesissa C, Anfossi P, Van't Klooster G, Mengelers M. The use of cultured hepatocytes from goats and cattle to investigate xenobiotic oxidative metabolism. Vet Res Commun 1996; 20:449-60. [PMID: 8908725 DOI: 10.1007/bf00419182] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The oxidative metabolism of aldicarb (ALD), a carbamate pesticide, and fenbendazole (FBZ), an anthelmintic, was studied using cultured hepatocytes obtained from 4 goats and a bullock and incubated with ALD (50 mumol/L) and FBZ (10 mumol/L). The parent compounds and the metabolites were measured by HPLC. Both compounds are metabolized at the sulphur atom via two sequential oxidations, first to the sulphoxide (aldicarb sulphoxide and oxfendazole, respectively) and then to the sulphone. Oxfendazole and fenbendazole sulphone from FBZ, and aldicarb sulphoxide from ALD were found in both species. Aldicarb sulphone was not produced by the hepatocyte preparations from the bullock. The good correlation obtained comparing the in vitro results of FBZ metabolism with published in vivo data obtained on FBZ kinetics in the same species confirmed the usefulness of in vitro models for predictive analysis of in vivo xenobiotic biotransformations.
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Affiliation(s)
- C Montesissa
- Institute of Veterinary Pathology and Hygiene, Faculty of Veterinary Medicine, University of Padova, Agripolis, Legnaro, Italy
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Karlik W, Fink-Gremmels J, Garwacki S, Van't Klooster G, van Miert A, Wiechetek M. The influence of nitrite, nitrate and nitric oxide on ammonia use and urea production in primary cultures of sheep hepatocytes. Toxicol In Vitro 1995; 9:711-6. [DOI: 10.1016/0887-2333(95)00058-g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/1995] [Indexed: 01/24/2023]
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van 't Klooster GA, Woutersen-van Nijnanten FM, Blaauboer BJ, Noordhoek J, van Miert AS. Applicability of cultured hepatocytes derived from goat, sheep and cattle in comparative drug metabolism studies. Xenobiotica 1994; 24:417-28. [PMID: 8079501 DOI: 10.3109/00498259409043245] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
1. Using trimethoprim (TMP), scoparone (SCOP), ethylmorphine (EtM), 1-naphthol (1-N) and phenol red (PhR) as test substrates, biotransformation activities were investigated in cultured hepatocytes from male and female rat, male and female goat, and female sheep and cattle. 2. As compared with rat hepatocytes, the total culture cytochrome P450 content was relatively well maintained in ruminant hepatocytes. In 72 h, it decreased to approximately half the initial content, whereas in rat hepatocytes only 30% was maintained. In ruminant hepatocytes, sulphation of 1-N remained fairly stable, glucuronidation of PhR decreased gradually, and glucuronidation of 1-N increased during the 72-h culture period. 3. Oxidative metabolism of TMP was rapid in goat and sheep hepatocytes, as compared with rat hepatocytes, reflecting species differences in TMP pharmacokinetics in vivo. In contrast with rat hepatocytes, 6-O-demethylation was by far the major pathway of scoparone metabolism in ruminant hepatocytes. The glucuronidation and sulphation activities were similar among the species. 4. In goat liver cells, sex differences in some oxidative biotransformations were observed, females being more active than males. In rat hepatocytes, a reverse sex difference was observed. 5. In conclusion, cultured hepatocytes from agricultural target species appear a useful in vitro model to study comparative metabolism of veterinary drugs and other xenobiotics. Comparing rat and ruminant, sex and species differences and similarities in drug metabolism can be observed that reflect the in vivo situation.
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Affiliation(s)
- G A van 't Klooster
- Department of Veterinary Basic Sciences, University of Utrecht, The Netherlands
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18
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van 't Klooster GA, Blaauboer BJ, Noordhoek J, van Miert AS. Sulfadimidine metabolism in vitro: II. Comparative studies in cultured rat, goat, sheep and cattle hepatocytes. J Vet Pharmacol Ther 1993; 16:454-61. [PMID: 8126762 DOI: 10.1111/j.1365-2885.1993.tb00211.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Hydroxylation and acetylation of sulphadimidine (SDD) and the deacetylation of N4-acetyl SDD was investigated in cultured hepatocytes from male and female rats, from male and female goats and from female sheep and cattle. Significant sex differences were observed for hydroxylation of SDD in hepatocytes from rat and goat. In goat, sheep and cow hepatocytes, the hydroxylation pathway is relatively important, whereas in rat hepatocytes, acetylation is predominant. Hepatocytes of all four species deacetylated N4-acetyl SDD. In ruminant hepatocytes, deacetylating activity was of considerable importance, whereas in rat hepatocytes, it appeared a minor pathway of metabolism. Similar to the in vivo situation, formation of N4-acetyl SDD in cultured hepatocytes results from an equilibrium of acetylation and deacetylation. A good correlation was found between results in isolated hepatocytes and previous findings in vivo, both in levels of species-related activities and in acetylation-hydroxylation ratios. In conclusion, cultured hepatocytes appear a useful in vitro model to study comparative sulfonamide metabolism.
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Affiliation(s)
- G A van 't Klooster
- Department of Veterinary Pharmacology, Pharmacy and Toxicology, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands
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van 't Klooster GA, Blaauboer BJ, Noordhoek J, van Miert AS. Cytochrome P450 induction and metabolism of alkoxyresorufins, ethylmorphine and testosterone in cultured hepatocytes from goats, sheep and cattle. Biochem Pharmacol 1993; 46:1781-90. [PMID: 8250964 DOI: 10.1016/0006-2952(93)90583-i] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Very little is known of cytochrome P450 (P450) patterns and enzyme characteristics in food-producing animal species. Oxidative metabolism of alkoxyresorufins, ethylmorphine (EtM) and testosterone (TST) was used to monitor the effects of the P450 inducers phenobarbital (PB), beta-naphthoflavone (BNF), dexamethasone (DEX) and triacetyloleandomycin (TAO) in primary cultured hepatocytes from goats, sheep and cattle. BNF effectively and specifically induced ethoxyresorufin deethylase (> 20-fold), indicating the presence of an inducible P450 1A form, and down-regulated EtM demethylation and most selected TST hydroxylations. In non-induced hepatocyte cultures, TST was metabolized to 6 beta-, 2 beta-, 12 beta-, and 11 alpha-hydroxy-TST (OHT). PB and, to a lesser extent, DEX non-specifically induced all OHT formations, and EtM demethylation. TAO almost completely inhibited OHT formation and EtM demethylation. These results indicate the involvement of principally one P450 form, or a restricted number of related P450 forms, presumably belonging to the P450 3A subfamily. In western blot analysis, cross reactivity was found with rat anti-P450 3A1 and anti-sheep P450 3A. A more specific PB effect was observed for 16 alpha-OHT, which may be formed though a ruminant P450 2B form. None of the inducers influenced pentoxyresorufin depentylase (PROD) or EtM O-deethylation. Metabolite patterns and inducibility of selected activities in ruminant hepatocytes are in accordance with previous findings in goats in vivo. Cytochrome P450 characteristics in ruminants appear to differ from those in rats whereas similarities to the situation in humans appear to exist.
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Affiliation(s)
- G A van 't Klooster
- Department of Veterinary Pharmacology and Toxicology, University of Utrecht, The Netherlands
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van't Klooster GA, Woutersen-van Nijnanten FM, Kolker HJ, Noordhoek J, van Miert AS. Improved high-performance liquid chromatographic method for the determination of ethylmorphine and its metabolites in microsomal incubations and cell culture media. JOURNAL OF CHROMATOGRAPHY 1992; 579:158-64. [PMID: 1447343 DOI: 10.1016/0378-4347(92)80374-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Ethylmorphine N-demethylation is used as a marker pathway in studies of rat cytochrome P450 3A and 2C11 biotransformations. At present, microsomal activities are generally measured by a colorimetric determination of the formed formaldehyde. In the present study, a high-performance liquid chromatographic method of separating and quantifying both the N-demethylated (norethylmorphine) and the O-de-ethylated (morphine) metabolites is described. Either samples are extracted with ethyl acetate or proteins are precipitated with zinc sulphate-barium hydroxide. Separation is achieved on a CN reversed-phase column, using a mobile phase of phosphate buffer (pH 4.5)-acetonitrile (90:10, v/v). At a flow-rate of 1.5 ml/min, the analysis time is 30 min. The limit of detection (ultraviolet, 210 nm) for ethylmorphine and its metabolites is 0.5 micrograms/ml.
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Affiliation(s)
- G A van't Klooster
- Department of Veterinary Basic Sciences, University of Utrecht, Netherlands
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