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Torrens A, Roy P, Lin L, Vu C, Grimes D, Inshishian VC, Montesinos JS, Ahmed F, Mahler SV, Huestis MA, Das A, Piomelli D. Comparative Pharmacokinetics of Δ 9-Tetrahydrocannabinol in Adolescent and Adult Male and Female Rats. Cannabis Cannabinoid Res 2022; 7:814-826. [PMID: 35353551 PMCID: PMC9784615 DOI: 10.1089/can.2021.0205] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Introduction: Studies in rodent models have shown that adolescent exposure to Δ9-THC, the psychotropic constituent of cannabis, produces long-lasting alterations in brain function and behavior. However, our understanding of how age and sex might influence the distribution and metabolism of THC in laboratory rodents is still incomplete. In the present report, we provide a comparative analysis of the pharmacokinetic (PK) properties of THC in adolescent and adult rats of both sexes, and outline several dissimilarities across these groups. Materials and Methods: A single (acute) or 2-week daily (subchronic) administration of THC (0.5 or 5 mg/kg, acute; 5 mg/kg, subchronic; intraperitoneal) was given to adolescent (33-day-old, acute; 30-44-day-old, subchronic) and young adult (70-day-old, acute only) male and female rats. THC and its first-pass metabolites-11-hydroxy-Δ9-THC (11-OH-THC) and 11-nor-9-carboxy-Δ9-THC (11-COOH-THC)-were quantified in plasma and brain tissue using a selective isotope-dilution liquid chromatography/tandem mass spectrometry assay. Changes in body temperature were measured using abdominally implanted microchips. Biotransformation of THC to its metabolites using freshly prepared liver microsomes was assessed. Results: At the acute 5 mg/kg dose, maximal plasma concentrations of THC were twice as high in adult than in adolescent rats. Conversely, in adults, brain concentrations and brain-to-plasma ratios for THC were substantially lower (25-50%) than those measured in adolescents. Similarly, plasma and brain concentrations of THC metabolites were higher in adolescent male rats compared with adult males. Interestingly, plasma and brain concentrations of the psychoactive THC metabolite 11-OH-THC were twofold to sevenfold higher in female animals of both ages compared with males. Moreover, liver microsomes from adolescent males and adolescent and adult females converted THC to 11-OH-THC twice as fast as adult male microsomes. A dose-dependent hypothermic response to THC was observed in females with 0.5 and 5 mg/kg THC, whereas only the highest dose elicited a response in males. Finally, subchronic administration of THC during adolescence did not significantly affect the drug's PK profile. Conclusions: The results reveal the existence of multiple age and sex differences in the distribution and metabolism of THC in rats, which might influence the pharmacological response to the drug.
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Affiliation(s)
- Alexa Torrens
- Department of Anatomy and Neurobiology, University of California, Irvine, California, USA
| | - Pritam Roy
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Lin Lin
- Department of Anatomy and Neurobiology, University of California, Irvine, California, USA
| | - Cindy Vu
- Department of Anatomy and Neurobiology, University of California, Irvine, California, USA
| | - Dakota Grimes
- Department of Anatomy and Neurobiology, University of California, Irvine, California, USA
| | - Victoria C. Inshishian
- Department of Neurobiology and Behavior, University of California, Irvine, California, USA
| | - Johanna S. Montesinos
- Department of Neurobiology and Behavior, University of California, Irvine, California, USA
| | - Faizy Ahmed
- Department of Anatomy and Neurobiology, University of California, Irvine, California, USA
| | - Stephen V. Mahler
- Department of Neurobiology and Behavior, University of California, Irvine, California, USA
| | - Marylin A. Huestis
- Institute of Emerging Health Professions, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Aditi Das
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Daniele Piomelli
- Department of Anatomy and Neurobiology, University of California, Irvine, California, USA
- Department of Biological Chemistry, and University of California, Irvine, California, USA
- Department of Pharmaceutical Sciences, University of California, Irvine, California, USA
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Watanabe K, Arai M, Narimatsu S, Yamamoto I, Yoshimura H. Effect of repeated administration of 11-hydroxy-delta 8-tetrahydrocannabinol, an active metabolite of delta 8-tetrahydrocannabinol, on the hepatic microsomal drug-metabolizing enzyme system of mice. Biochem Pharmacol 1986; 35:1861-5. [PMID: 3013200 DOI: 10.1016/0006-2952(86)90304-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effects of delta 8-tetrahydrocannabinol (delta 8-THC) and its major and active metabolite, 11-hydroxy-delta 8-tetrahydrocannabinol (11-OH-delta 8-THC), on the hepatic microsomal drug-metabolizing enzyme system were studied in mice. The repeated administration of 11-OH-delta 8-THC (5 mg/kg/day, i.v.) for 3 or 7 days increased significantly the activities of aniline hydroxylase and p-nitroanisole O-demethylase. By the same treatment, cytochrome P-450 content (3 days) or NADPH-cytochrome c reductase activity (7 days) was also increased significantly. The treatment with delta 8-THC for 7 days (5 mg/kg/day, i.v.) significantly increased aniline hydroxylase only. 11-OH-delta 8-THC increased the Vmax, but not the Km, values for both drug-metabolizing enzymes, whereas delta 8-THC decreases significantly the Km value (270 microM) for p-nitroanisole O-demethylase as compared with the control (398 microM). Repeated administration of these cannabinoids for 7 days also increased the metabolism of delta 8-THC by hepatic microsomes; this was attributed to an enhanced formation of 11-OH-delta 8-THC. In contrast, microsomal formation of 7 alpha-OH-delta 8-THC was decreased significantly by treatment with delta 8-THC. 11-OH-delta 8-THC, but not delta 8-THC, treatment increased the metabolism of 11-OH-delta 8-THC by hepatic microsomes. These findings indicate that delta 8-THC and 11-OH-delta 8-THC treatment can induce hepatic microsomal drug-metabolizing enzymes and affect differently the catalytic properties of the enzymes.
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