Influence of thyroid hormones on 3,4-methylenedioxymethamphetamine-induced thermogenesis and reinforcing strength in monkeys.
Matthew L Banks, Paul W Czoty, Jon E. Sprague, Michael A Nader
Behavioural Pharmacology March 2008 DOI: 10.1097/fbp.0b013e3282f62c40 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Experimental animal study Peer reviewed |
|---|---|
| Sample size | 4 |
| Population | Rhesus monkeys |
| Interventions | Levothyroxine MDMA |
| Dose | Levothyroxine 3.0 or 4.5 micrograms/kg/day intramuscularly; MDMA 1.5 mg/kg intravenously for thermogenesis; MDMA 0.03-0.3 mg/kg/injection for self-administration |
| Topics | MDMA |
| Key findings | Chronic levothyroxine increased MDMA-induced thermogenesis in rhesus monkeys but had no effect on MDMA choice in a concurrent food-drug self-administration task. The authors suggest that changes in thyroxine levels do not parallel the changes in ambient temperature in altering the reinforcing strength of MDMA. |
Abstract
In monkeys, elevating ambient temperature has been shown to increase sensitivity to 3,4-methylenedioxymethamphetamine (MDMA) reinforcement. Earlier rodent studies have shown that elevations in thyroid levels (hyperthyroidism) parallel changes in elevating the ambient temperature on MDMA-induced thermogenesis, but the interaction has not been examined in monkeys. This study was designed to evaluate the effects of chronic levothyroxine (3.0 or 4.5 microg/kg/day, intramuscularly; Levo) treatment on MDMA-induced increases in body temperature following 1.5 mg/kg (intravenously) MDMA and self-administration when MDMA (0.03-0.3 mg/kg/injection) and food were available under a concurrent fixed-ratio 30 schedule of reinforcement in rhesus monkeys (n=4). Earlier studies had shown that 1.5 mg/kg MDMA did not affect thermoregulation at 24 degrees C. Chronic Levo treatment resulted in significant increases in MDMA-induced thermogenesis. In the self-administration experiment, MDMA choice increased with dose, such that food was preferred over saline and a low MDMA dose (0.03 mg/kg/injection), whereas 0.1 and 0.3 mg/kg/injection MDMA was preferred over food. Although elevating ambient temperature had been shown to increase MDMA potency, there was no effect of chronic Levo treatment on MDMA choice. These results suggest that changes in thyroxine levels do not parallel the changes in ambient temperature in altering the reinforcing strength of MDMA.
Comparable studies
Other preclinical and animal studies on MDMA, most cited first.
Citations in the library
Cited by 3
- MDMA Self-Administration in Laboratory Animals: A Summary of the Literature and Proposal for Future Research Neuropsychobiology 2009
- Drug seeking in response to a priming injection of MDMA in rats: relationship to initial sensitivity to self-administered MDMA and dorsal striatal dopamine The International Journal of Neuropsychopharmacology March 25, 2010
- Assessment of the Reinforcing Properties of Orally Administered MDMA ('Ecstasy') in Rats 2010
Cites 3
- Effects of ambient temperature on the relative reinforcing strength of MDMA using a choice procedure in monkeys. Psychopharmacology January 2008
- Ambient temperature effects on 3,4-methylenedioxymethamphetamine-induced thermodysregulation and pharmacokinetics in male monkeys. Drug Metabolism and Disposition October 2007
- Does hyperthyroidism increase risk of death due to the ingestion of ecstasy? Journal of Forensic Sciences July 2007