Pharmacokinetic and pharmacodynamic properties of aerosolized ("vaped") THC in adolescent male and female rats.
C M Ruiz, Alexa Torrens, Valeria Lallai, E Castillo, Letizia Manca, M X Martinez, D N Justeson, Christie D Fowler, Daniele Piomelli, S V Mahler
Psychopharmacology December 2021 DOI: 10.1007/s00213-021-05976-8 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Preclinical pharmacokinetic and pharmacodynamic study in rodents Peer reviewed |
|---|---|
| Population | Adolescent Wistar rats of both sexes |
| Dose | 25 or 100 mg/ml, 30-min inhalation exposure |
| Duration | 30-min aerosol dosing session; measurements at 5, 30, 60, and 120 min after dosing; activity measured for 120 min after aerosol |
| Measures | Liquid chromatography/mass spectrometry for THC and metabolites in blood plasma and brain tissue; activity in a novel environment; body temperature |
| Topics | Anxiety Cannabis |
| Keywords | Blood Brain E-cigarette Inhalation Locomotion Pharmacodynamics Pharmacokinetics Vapor |
| Key points | Sex-dependent differences appeared in the pharmacokinetics of THC and its active (11-OH-THC) and inactive (11-COOH-THC) metabolites in blood and brain, along with dose- and sex-dependent effects on anxiety-like and exploratory behaviors. Females showed greater 11-OH-THC levels and stronger behavioral effects at the low dose, while hypothermic effects were similar in both sexes at the high dose. |
Abstract
Adolescent exposure to ∆9-tetrahydrocannabinol (THC), the psychotropic constituent of cannabis, might affect brain development, and in rodent models leads to long-term behavioral and physiological alterations. Yet, the basic pharmacology of this drug in adolescent rodents, especially when ingested via ecologically relevant routes like aerosol inhalation, commonly referred to as "vaping," is still poorly characterized. Moreover, sex differences exist in THC metabolism, kinetics, and behavioral effects, but these have not been rigorously examined after vapor dosing in adolescents. We investigated the pharmacokinetics and pharmacodynamics of aerosolized THC (30 min inhalation exposure, 25 or 100 mg/ml) in adolescent Wistar rats of both sexes. Liquid chromatography/mass spectrometry analysis of THC and its major metabolites was conducted on blood plasma and brain tissue at 5, 30, 60, and 120 min following a 30-min aerosol dosing session. Effects on activity in a novel environment for 120 min after aerosol, and temperature, were measured in separate rats. We found sex-dependent differences in the pharmacokinetics of THC and its active (11-OH-THC) and inactive (11-COOH-THC) metabolites in the blood and brain, along with dose- and sex-dependent effects on anxiety-like and exploratory behaviors; namely, greater 11-OH-THC levels accompanied by greater behavioral effects in females at the low dose but similar hypothermic effects in both sexes at the high dose. These results provide a benchmark for dosing adolescent rats with aerosolized (or "vaped") THC, which could facilitate adoption by other labs of this potentially human-relevant THC exposure model to understand cannabis effects on the developing brain.
Comparable studies
Other preclinical and animal studies on cannabis for anxiety, most cited first.