The pharmacology of the acute hyperthermic response that follows administration of 3,4‐methylenedioxymethamphetamine (MDMA, ‘ecstasy’) to rats
British Journal of Pharmacology – January 01, 2002
Source: OpenAlex
Summary
MDMA, commonly known as ecstasy, can trigger significant hyperthermia in rats, with a dose of 12.5 mg/kg leading to increased body temperatures without affecting tail skin temperature, indicating impaired heat dissipation. Notably, the dopamine D1 antagonist SCH 23390 effectively reduced this hyperthermic response in a dose-dependent manner. In contrast, various serotonin receptor antagonists and uptake inhibitors did not mitigate hyperthermia. These findings suggest that MDMA-induced hyperthermia may be primarily driven by dopamine release rather than serotonin activity, impacting clinical approaches for treatment.
Abstract
The pharmacology of the acute hyperthermia that follows 3,4‐methylenedioxymethamphetamine (MDMA, ‘ecstasy’) administration to rats has been investigated. MDMA (12.5 mg kg −1 i.p.) produced acute hyperthermia (measured rectally). The tail skin temperature did not increase, suggesting that MDMA may impair heat dissipation. Pretreatment with the 5‐HT 1/2 antagonist methysergide (10 mg kg −1 ), the 5‐HT 2A antagonist MDL 100,907 (0.1 mg kg −1 ) or the 5‐HT 2C antagonist SB 242084 (3 mg kg −1 ) failed to alter the hyperthermia. The 5‐HT 2 antagonist ritanserin (1 mg kg −1 ) was without effect, but MDL 11,939 (5 mg kg −1 ) blocked the hyperthermia, possibly because of activity at non‐serotonergic receptors. The 5‐HT uptake inhibitor zimeldine (10 mg kg −1 ) had no effect on MDMA‐induced hyperthermia. The uptake inhibitor fluoxetine (10 mg kg −1 ) markedly attenuated the MDMA‐induced increase in hippocampal extracellular 5‐HT, also without altering hyperthermia. The dopamine D 2 antagonist remoxipride (10 mg kg −1 ) did not alter MDMA‐induced hyperthermia, but the D 1 antagonist SCH 23390 (0.3 – 2.0 mg kg −1 ) dose‐dependently antagonized it. The dopamine uptake inhibitor GBR 12909 (10 mg kg −1 ) did not alter the hyperthermic response and microdialysis demonstrated that it did not inhibit MDMA‐induced striatal dopamine release. These results demonstrate that in vivo MDMA‐induced 5‐HT release is inhibited by 5‐HT uptake inhibitors, but MDMA‐induced dopamine release may not be altered by a dopamine uptake inhibitor. It is suggested that MDMA‐induced hyperthermia results not from MDMA‐induced 5‐HT release, but rather from the increased release of dopamine that acts at D 1 receptors. This has implications for the clinical treatment of MDMA‐induced hyperthermia. British Journal of Pharmacology (2002) 135 , 170–180; doi: 10.1038/sj.bjp.0704442