PT - JOURNAL ARTICLE AU - B. Bhagat TI - PRESSOR RESPONSES TO AMPHETAMINE IN THE SPINAL CAT AND ITS INFLUENCE ON TACHYPHYLAXIS TO TYRAMINE DP - 1965 Aug 01 TA - Journal of Pharmacology and Experimental Therapeutics PG - 206--211 VI - 149 IP - 2 4099 - http://jpet.aspetjournals.org/content/149/2/206.short 4100 - http://jpet.aspetjournals.org/content/149/2/206.full SO - J Pharmacol Exp Ther1965 Aug 01; 149 AB - Studies of the development of tachyphylaxis to amphetamine in spinal cats have shown that tachyphylaxis was developed rapidly, and was not accompanied by any change in cardiac catecholamine levels. The tachyphylaxis was specific, and could not be "crossed over" to tyramine. Amphetamine hastened the development of tachyphylaxis to tyramine. The development of tachyphylaxis to amphetamine was not altered by injections of tyramine. The rate of fall in specific activity of myocardial norepinephrine after administration of labeled catecholamine did not change in animals treated with successive doses of amphetamine, but increased in animals treated with tyramine. Amphetamine prevented the "escape" from tachyphylaxis to tyramine without influencing the tyramine-induced release of catecholamine from the heart. The mechanism of tachyphylaxis to amphetamine appears to differ from that to tyramine. The Williams & Wilkins Comapny