D F Dougan

Learn More
The stereoselective accumulation of alpha-methyl-p-tyramine (AMPT) and alpha-methyl-p-octopamine (AMPO) in rat striatum and hypothalamus after acute and chronic administration of the (+)- and (-)-isomers of amphetamine (Amphet) and the acute administration of (+)- and (-)-AMPT has been investigated by chemical ionization gas chromatography mass spectrometry(More)
The concentration in rat striatum of the meta and para isomers of tyramine and alpha-methyltyramine, after the administration of (+)-amphetamine, alpha-methyl-p-tyrosine (AMPT) and alpha-methylphenylalanine (AMPA) has been determined using chemical ionization gas chromatography mass spectrometry (c.i.g.c.m.s.). Twenty hours after the last of 7 daily(More)
The mechanism underlying the modulation, by dextroamphetamine and compounds related to phenylethanolamine, of responses to dopamine and serotonin has been studied in the isolated ventricle and aortic bulb of the clam Tapes watlingi. Dextroamphetamine and phenylethanolamine but not cocaine and benztropine have the ability to unmask inhibitory responses to(More)
The effect of the invertebrate octopamine agonists chlordimeform and clonidine on the concentration and turnover of p-octopamine and m- and p-tyramine was determined in rat hypothalamus and striatum. Clonidine (0.25 mg/Kg, s.c.) did not alter the concentration of p-octopamine in the hypothalamus or p-tyramine in the striatum. Administration of chlordimeform(More)
Behavioural studies showed that administration of alpha-methyl-p-tyramine (AMT; 10 mg/kg i.p.) to rats 24 hr before treatment with d-amphetamine (AMPHET; 4 mg/kg i.p.) resulted in augmentation of AMPHET-induced stereotype activity. Parallel experiments involving electro-chemical estimation of dopamine metabolites in the striatum showed that the decrease in(More)
The presence of specific, stereo-selective octopamine receptors has been demonstrated in the non-spontaneously beating accessory ventricle (aortic bulb) of the clam Tapes watlingi. Analogues of octopamine with a single chloro group in either the para or meta positions of the benzene ring were 10 times less potent than octopamine in their agonist activity.(More)
A method has been developed for the quantitation of the putative phenolamine neurotransmitter octopamine, and its precursor tyramine, in brain tissue. The procedure employs methane chemical ionization of the pentafluoropropionate derivatives of octopamine and tyramine together with the use of deuterated internal standards and selected ion monitoring.(More)
1. Sulpiride, but not procainamide, antagonizes the excitatory effects of (+/-)-octopamine receptors in the Tapes ventricle. Neither compound attenuates dopamine excitation. 2. Clozapine will attenuate the effects of (+/-)-octopamine and (-)-alpha-methyl octopamine at the octopamine receptor but not the excitatory effect of dopamine at dopamine receptors.(More)
  • 1