Biology subjects

Coons, T. R.

Publications and source records attributed to Coons, T. R..

2 recordsLinked to original sources

bioRxiv2026

Effects of vapor inhalation of 6-methyl nicotine in female and male rats

Background: The nicotine analog 6-methyl nicotine (6-MN) has appeared in commercial e-cigarette liquids, and other products, spurring interest in determining the extent to which it conveys similar effects to those of nicotine. Objective: To determine if 6-MN acts like nicotine to decrease body temperature, decrease nociception, suppress wheel activity and reinforce operant behavior when delivered by vapor inhalation using an Electronic Nicotine Delivery System (ENDS; "e-cigarette") approach in a rat model. Methods: Male and female (N=8 per sex) young adult Sprague-Dawley rats were evaluated for rectal temperature and nociceptive responses (warm water tail-withdrawal) to the inhalation of vapor from (-)-6-MN or (-)-nicotine in concentrations ranging from 5-30 mg/mL in the propylene glycol vehicle. Rats were then assessed for the reinforcing effects of nicotine and 6-MN using a vapor self-administration procedure and the rate suppressing effects of nicotine and 6-MN on wheel activity following injection. Results: Inhalation of nicotine or 6-MN for 30 minutes decreased the rectal temperature and increased tail-withdrawal latency of female and male rats in a concentration-dependent manner. The magnitude of the effects of 6-MN and nicotine were similar at similar vapor concentrations. Operant responding for 6-MN vapor was increased by pre-treatment with the antagonist mecamylamine. 6-MN was more potent than nicotine at suppressing wheel activity after injection. Conclusions: 6-MN induces effects very similar to those of nicotine, at a similar potency when inhaled and at a slightly increased potency when injected.

pharmacology and toxicology↗

bioRxiv2025

Effects of 6-methyl nicotine in middle aged female rats with a history of nicotine vapor self-administration

RationaleThe nicotine analog 6-methyl nicotine (6-MN) has recently appeared in non-tobacco nicotine delivery products, including oral pouches and e-cigarette liquids, in an apparent ploy to evade regulation of nicotine by the United States Food and Drug Administration or other public health agencies. Unfortunately, only minimal scientific information on the effects of 6-MN is available. ObjectiveTo determine the extent to which 6-MN produces nicotine-like effects on body temperature, wheel activity and nociception in laboratory rodents. MethodsMiddle-aged (starting at Post Natal Day 425) female Wistar rats were evaluated for rectal temperature, voluntary wheel activity, and nociceptive responses (warm water tail-withdrawal) to subcutaneous injection of nicotine (0.0, 0.8 mg/kg) or 6-methyl nicotine (6-MN; 0.0, 0.4, 0.8 mg/kg). Temperature and nociceptive responses to vapor inhalation of 6-MN [0-30 mg/mL in the propylene glycol (PG) vehicle] were assessed. Finally, the self-administration of 6-MN vapor was compared with nicotine vapor self-administration. Results6-MN decreased rectal temperature, suppressed wheel activity and induced modest nociceptive effects. The magnitude of the effect of 0.8 mg/kg 6-MN and 0.8 mg/kg nicotine were similar across all three assays. Vapor self-administration of 6-MN and nicotine was likewise comparable at a 10 mg/mL concentration. Conclusion6-MN administered by injection or by vapor inhalation produces behavioral and physiological effects that are very similar to those produced by nicotine in rats. It is therefore likely that detrimental health effects of 6-MN will be quite similar to those established for nicotine.

pharmacology and toxicology↗