%0 Journal Article
%T Defunct brain stem cardiovascular regulation underlies cardiovascular collapse associated with methamphetamine intoxication
%A Faith CH Li
%A JC Yen
%A Samuel HH Chan
%A Alice YW Chang
%J Journal of Biomedical Science
%D 2012
%I BioMed Central
%R 10.1186/1423-0127-19-16
%X The distribution of METH in brain and heart on intravenous administration in male Sprague-Dawley rats, and the resultant changes in arterial pressure (AP), heart rate (HR) and indices for baroreflex-mediated sympathetic vasomotor tone and cardiac responses were evaluated, alongside survival rate and time.Intravenous administration of METH (12 or 24 mg/kg) resulted in a time-dependent and dose-dependent distribution of the psychostimulant in brain and heart. The distribution of METH to neural substrates associated with brain stem cardiovascular regulation was significantly larger than brain targets for its neurological and psychological effects; the concentration of METH in cardiac tissues was the lowest among all tissues studied. In animals that succumbed to METH, the baroreflex-mediated sympathetic vasomotor tone and cardiac response were defunct, concomitant with cessation of AP and HR. On the other hand, although depressed, those two indices in animals that survived were maintained, alongside sustainable AP and HR. Linear regression analysis further revealed that the degree of dampening of brain stem cardiovascular regulation was positively and significantly correlated with the concentration of METH in key neural substrate involved in this homeostatic mechanism.We conclude that on intravenous administration, METH exhibits a preferential distribution to brain stem nuclei that are associated with cardiovascular regulation. We further found that the concentration of METH in those brain stem sites dictates the extent that baroreflex-mediated sympathetic vasomotor tone and cardiac responses are compromised, which in turn determines survival or fatality because of cardiovascular collapse.The psychostimulant methamphetamine (METH; N-methyl-O-phenylisopropylamine) is among the most popular illegal drugs worldwide [1-4]. Based on records between 1998 and 2001 from the Ministry of Justice, Taiwan, it has been reported that this schedule II controlled drug is being used by
%U http://www.jbiomedsci.com/content/19/1/16