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Uno Y, Shimizu M, Yamazaki H. A variety of cytochrome P450 enzymes and flavin-containing monooxygenases in dogs and pigs commonly used as preclinical animal models. Biochem Pharmacol 2024:116124. [PMID: 38490520 DOI: 10.1016/j.bcp.2024.116124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 02/29/2024] [Accepted: 03/11/2024] [Indexed: 03/17/2024]
Abstract
Drug oxygenation is mainly mediated by cytochromes P450 (P450s, CYPs) and flavin-containing monooxygenases (FMOs). Polymorphic variants of P450s and FMOs are known to influence drug metabolism. Species differences exist in terms of drug metabolism and can be important when determining the contributions of individual enzymes. The success of research into drug-metabolizing enzymes and their impacts on drug discovery and development has been remarkable. Dogs and pigs are often used as preclinical animal models. This research update provides information on P450 and FMO enzymes in dogs and pigs and makes comparisons with their human enzymes. Newly identified dog CYP3A98, a testosterone 6β- and estradiol 16α-hydroxylase, is abundantly expressed in small intestine and is likely the major CYP3A enzyme in small intestine, whereas dog CYP3A12 is the major CYP3A enzyme in liver. The roles of recently identified dog CYP2J2 and pig CYP2J33/34/35 were investigated. FMOs have been characterized in humans and several other species including dogs and pigs. P450 and FMO family members have been characterized also in cynomolgus macaques and common marmosets. P450s have industrial applications and have been the focus of attention of many pharmaceutical companies. The techniques used to investigate the roles of P450/FMO enzymes in drug oxidation and clinical treatments have not yet reached maturity and require further development. The findings summarized here provide a foundation for understanding individual pharmacokinetic and toxicological results in dogs and pigs as preclinical models and will help to further support understanding of the molecular mechanisms of human P450/FMO functionality.
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Affiliation(s)
- Yasuhiro Uno
- Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima-city, Kagoshima 890-0065, Japan
| | - Makiko Shimizu
- Showa Pharmaceutical University, Machida, Tokyo 194-8543, Japan
| | - Hiroshi Yamazaki
- Showa Pharmaceutical University, Machida, Tokyo 194-8543, Japan.
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Jukier T, Gross A, Boothe D. Pharmacokinetics and tolerability of a veterinary phenobarbital product in healthy dogs. Front Vet Sci 2024; 10:1307888. [PMID: 38249559 PMCID: PMC10796454 DOI: 10.3389/fvets.2023.1307888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 12/07/2023] [Indexed: 01/23/2024] Open
Abstract
Introduction Phenobarbital has been used for many decades in both human and veterinary epileptic patients. Many formulations for a particular drug exist, most of which are marketed for humans. Recently a veterinary specific phenobarbital product has been introduced to the market in the United States. Utilizing a specific formulation to treat patients may help decrease the issue of bioequivalence between one pharmaceutical product to another. Therefore, the goal of this study was to determine single and multiple dosing pharmacokinetics and tolerability of a veterinary specific phenobarbital product over a 4-week time period. Materials and methods 8 Healthy dogs from a canine research colony were used in the study. Results Overall, this phenobarbital formulation was well tolerated in the dogs in this study. Cmax, Tmax, half-life, and AUC after single 12 mg/kg oral dose were 23.5 μg/mL, 4.2 h, 94 h, and 2,758 h*μg/mL. Following chronic dosing, these parameters were 29.1 μg/mL, 3.4 h, 70 h, and 2,971 h*μg/mL, respectively. Discussion This formulation demonstrated a mean absolute bioavailability of 100%, with similar pharmacokinetic properties to previously published data.
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Affiliation(s)
- Tom Jukier
- Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Amanda Gross
- Scott Ritchey Research Center, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Dawn Boothe
- Department of Anatomy, Physiology, and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
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Watanabe K, Kondo M, Ikenaka Y, Nakayama SMM, Ishizuka M. A Comparative Genomic and Phylogenetic Investigation of the Xenobiotic Metabolism Enzymes of Cytochrome P450 in Elephants Shows Loss in CYP2E and CYP4A. Animals (Basel) 2023; 13:1939. [PMID: 37370449 DOI: 10.3390/ani13121939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 06/04/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
Cytochrome P450 is an important enzyme that metabolizes a variety of chemicals, including exogenous substances, such as drugs and environmental chemicals, and endogenous substances, such as steroids, fatty acids, and cholesterol. Some CYPs show interspecific differences in terms of genetic variation. As little is known about the mechanisms of elephant metabolism, we carried out a comparative genomic and phylogenetic analysis of CYP in elephants. Our results suggest that elephant CYP genes have undergone independent duplication, particularly in the CYP2A, CYP2C, and CYP3A genes, a unique cluster specific to elephant species. However, while CYP2E and CYP4A were conserved in other Afrotheria taxa, their decay in elephants resulted in genetic dysfunction (pseudogene). These findings outline several remarkable characteristics of elephant CYP1-4 genes and provide new insights into elephant xenobiotic metabolism. Further functional investigations are necessary to characterize elephant CYP, including expression patterns and interactions with drugs and sensitivities to other chemicals.
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Affiliation(s)
- Kanami Watanabe
- Laboratory of Toxicology, Department of Environmental Veterinary Science, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
| | - Mitsuki Kondo
- National Institute for Environmental Studies (NIES) Biodiversity Division, Ecological Risk Assessment and Control Section, Tsukuba 305-8506, Japan
| | - Yoshinori Ikenaka
- Laboratory of Toxicology, Department of Environmental Veterinary Science, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2520, South Africa
- Translational Research Unit, Veterinary Teaching Hospital, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
- One Health Research Center, Hokkaido University, Sapporo 060-0818, Japan
| | - Shouta M M Nakayama
- Laboratory of Toxicology, Department of Environmental Veterinary Science, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
- Biomedical Sciences Department, School of Veterinary Medicine, The University of Zambia, P.O. Box 32379, Lusaka 10101, Zambia
| | - Mayumi Ishizuka
- Laboratory of Toxicology, Department of Environmental Veterinary Science, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
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Rochat B, Paus E, Maitre C, Baumann P. Citalopram in vitro metabolism in a Beagle dog: A role for CYP2D15 in the production of toxic didesmethylcitalopram? VET MED-CZECH 2023; 68:135-144. [PMID: 37982088 PMCID: PMC10581520 DOI: 10.17221/65/2022-vetmed] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Accepted: 03/13/2023] [Indexed: 11/21/2023] Open
Abstract
After administration of the serotonergic antidepressant citalopram (CIT) to Beagle dogs, the dogs may experience severe convulsive attacks in relation to the considerably higher plasma concentrations of the metabolite didesmethyl-CIT (DDCIT), when compared to those in humans medicated with CIT. This pilot study aimed at determining the role of cytochrome P-450 (CYP450) isozymes in the in vitro metabolism of CIT to desmethyl-CIT (DCIT), and of DCIT to DDCIT in the liver microsomes of a single Beagle dog. Incubations with racemic CIT or DCIT reveal a high-affinity enzyme with Km between 0.3 μM and 1.4 μM for S- and R-DCIT and S- and R-DDCIT productions, respectively. In comparison to human enzymes, the intrinsic clearance values of this high-affinity enzyme are between 15 μl/(min × mg of protein) and 52 μl/(min × mg of protein), i.e., very high. In vitro experiments with inhibitors suggest that CYP2D15, which shows an analogy with human CYP2D6, is by far the main CYP450 isozyme involved in the production of DCIT and DDCIT, whereas CYP3A12 and CYP2C21/41 showed a weak implication. These observations partly explain why, in humans, the plasma concentrations of the toxic DDCIT are considerably lower than those observed in dogs, after administration of CIT.
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Affiliation(s)
- Bertrand Rochat
- Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Department of Education and Research, University of Lausanne, Lausanne, Switzerland
- Bertrand Rochat, Erik Paus and Pierre Baumann contributed equally to this work
| | - Erik Paus
- Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland, and Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, Geneva, Switzerland
- Bertrand Rochat, Erik Paus and Pierre Baumann contributed equally to this work
| | - Cedric Maitre
- Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- PharmaciePlus Franches-Montagnes, Saignelégier, Switzerland
| | - Pierre Baumann
- Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Bertrand Rochat, Erik Paus and Pierre Baumann contributed equally to this work
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Specific Gene Duplication and Loss of Cytochrome P450 in Families 1-3 in Carnivora (Mammalia, Laurasiatheria). Animals (Basel) 2022; 12:ani12202821. [PMID: 36290207 PMCID: PMC9597770 DOI: 10.3390/ani12202821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 09/30/2022] [Accepted: 10/05/2022] [Indexed: 11/21/2022] Open
Abstract
Simple Summary In this study we investigated the specific duplication and loss events of cytochrome P450 (CYP) genes in families 1-3 in Carnivora. These genes have been recognized as essential detoxification enzymes, and, using genomic data, we demonstrated a synteny analysis of the CYP coding cluster and a phylogenetic analysis of these genes. We discovered the CYP2Cs and CYP3As expansion in omnivorous species such as the badger, the brown bear, the black bear, and the dog. Furthermore, phylogenetic analysis revealed the evolution of CYP2Cs and 3As in Carnivora. These findings are essential for the appropriate estimation of pharmacokinetics or toxicokinetic in wild carnivorans. Abstract Cytochrome P450s are among the most important xenobiotic metabolism enzymes that catalyze the metabolism of a wide range of chemicals. Through duplication and loss events, CYPs have created their original feature of detoxification in each mammal. We performed a comprehensive genomic analysis to reveal the evolutionary features of the main xenobiotic metabolizing family: the CYP1-3 families in Carnivora. We found specific gene expansion of CYP2Cs and CYP3As in omnivorous animals, such as the brown bear, the black bear, the dog, and the badger, revealing their daily phytochemical intake as providing the causes of their evolutionary adaptation. Further phylogenetic analysis of CYP2Cs revealed Carnivora CYP2Cs were divided into CYP2C21, 2C41, and 2C23 orthologs. Additionally, CYP3As phylogeny also revealed the 3As’ evolution was completely different to that of the Caniformia and Feliformia taxa. These studies provide us with fundamental genetic and evolutionary information on CYPs in Carnivora, which is essential for the appropriate interpretation and extrapolation of pharmacokinetics or toxicokinetic data from experimental mammals to wild Carnivora.
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Cloning and Functional Characterization of Dog OCT1 and OCT2: Another Step in Exploring Species Differences in Organic Cation Transporters. Int J Mol Sci 2022; 23:ijms23095100. [PMID: 35563491 PMCID: PMC9102066 DOI: 10.3390/ijms23095100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 04/28/2022] [Accepted: 04/30/2022] [Indexed: 12/21/2022] Open
Abstract
OCT1 and OCT2 are polyspecific membrane transporters that are involved in hepatic and renal drug clearance in humans and mice. In this study, we cloned dog OCT1 and OCT2 and compared their function to the human and mouse orthologs. We used liver and kidney RNA to clone dog OCT1 and OCT2. The cloned and the publicly available RNA-Seq sequences differed from the annotated exon-intron structure of OCT1 in the dog genome CanFam3.1. An additional exon between exons 2 and 3 was identified and confirmed by sequencing in six additional dog breeds. Next, dog OCT1 and OCT2 were stably overexpressed in HEK293 cells and the transport kinetics of five drugs were analyzed. We observed strong differences in the transport kinetics between dog and human orthologs. Dog OCT1 transported fenoterol with 12.9-fold higher capacity but 14.3-fold lower affinity (higher KM) than human OCT1. Human OCT1 transported ipratropium with 5.2-fold higher capacity but 8.4-fold lower affinity than dog OCT1. Compared to human OCT2, dog OCT2 showed 10-fold lower transport of fenoterol and butylscopolamine. In conclusion, the functional characterization of dog OCT1 and OCT2 reported here may have implications when using dogs as pre-clinical models as well as for drug therapy in dogs.
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