You are here:
EFFECTS OF 3,4-METHYLDENDIOXYMETHAMPHETAMINE ON AUTONOMIC THERMOREGULATORY RESPONSES OF THE RAT
Citation:
Gordon, C., W. Watkinson, J. O'Callaghan, AND D. Miller. EFFECTS OF 3,4-METHYLDENDIOXYMETHAMPHETAMINE ON AUTONOMIC THERMOREGULATORY RESPONSES OF THE RAT. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-91/021 (NTIS PB91183459).
Description:
3,4-methylenedioxymethamphetamine (MDMA), a substituted amphetamine analogue which stimulates serotonin release in the CNS, has been shown to induce near lethal elevations in core temperature in the rat. o characterize the effects of MDMA on temperature regulation, we measured metabolic rate (MR), evaporative water loss ([WI), motor activity (MA), and colonic temperature (Tc) in male, Long-Evans rats at 60 min following 30 mg/kg (s.c.) MDMA or saline at ambient temperatures (Ta) of 10, 20, and 30 degrees C. DMA caused an elevation in MR at Ta's of 20 and 30 degrees C but had no effect at 10 degrees C. t a Ta of 30 degrees C, MR of the MDMA group was double that of the saline group. WL was elevated by MDMA, an effect which was potentiated with increasing Ta. DMA also elicited an increase in MA at all three Ta's. DMA led to a 3.2 degrees C increase in Tc at 30 degrees C, no change in T6 at 20 degrees C, and a 2.0 degrees C decrease in Tc at 10 degrees C. A second study found that rats treated with 20 mg/kg MDMA failed to demonstrate an increase in blood flow to the tail in spite of a hyperthermic core temperature of 41.4 degrees C. reliminary studies using radiotelemetry methodology suggested that MDMA lethality is preceded by precipitous elevations in heart rate and core temperature. he data suggest that, at relatively warm Ta's, MDMA-induced stimulation of serotonergic pathways causes an elevation in MR and peripheral vasoconstriction, thus producing life-threatening elevations in Tc. he increase in EWL following MDMA partially attenuates the hyperthermia at warm Ta's and leads to hypothermia in the rat maintained at a cold Ta of 10 degrees C.