Physiological and Pharmacokinetic Effects of E‐cigarette Type Exposure to Δ9‐Tetrahydrocannabinol (THC)

Abstract

The increase in availability of electronic cigarettes (e‐cigarettes) for delivery of nicotine has led to the adaptation of these devices for the delivery of marijuana. Although there have been studies investigating the effects of intrapulmonary delivery of Δ9‐tetrahydrocannabinol (THC), no studies have investigated the effects of e‐cigarette type exposure in rodents. The goal of this study was to determine if vapor delivery of THC using e‐cigarette technology would produce cannabinoid‐typical effects observed in rodents using other routes of administration. Male Wistar rats received an injection of THC (0.3–10 mg/kg,i.p.) or were exposed to vaporized THC or crude marijuana extract in propylene glycol (PG) vehicle (200 mg/mL and 400 mg/mL respectively; 4 puffs per 5 min for 10–40 min). Rats were tested for changes in body temperature and nociception, and plasma THC content was analyzed using fast liquid chromatography/mass spectrometry (LC/MS). Vapor exposure to THC or crude extract significantly reduced body temperature up to 165 min following vape initiation. Tail flick latency was assessed using a hot water bath (52°C), and results showed increased latency up to 60 min post‐vape initiation. Plasma THC levels following a 10 mg/kg intraperitoneal injection were similar to levels produced by 30 min of inhalation exposure to THC in PG. Our results demonstrate that intrapulmonary delivery of THC using‐e‐cigarette type devices produces physiological effects, and this study validates this novel method of intrapulmonary THC delivery in rats.Support or Funding InformationDA024105 and DA035482