J A Garcia-Sevilla

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After two weeks of twice-daily administration of amitriptyline to rats, the binding of [3H]clonidine to presynaptic alpha 2-adrenoreceptors was decreased in membranes isolated from 5 areas of the rat brain. After one day of treatment, binding did not differ from saline treated controls. In vitro, a high concentration of amitriptyline caused a competitive(More)
The aim of this study was to quantitate the turnover of alpha 2-adrenoceptors in different regions of the rat brain and its modulation during desipramine (a cyclic antidepressant drug)-induced receptor down-regulation. The recovery of [3H]clonidine (a mixed alpha 2A/B-adrenoceptor agonist) binding after irreversible inactivation by(More)
The alpha-2 adrenoceptor antagonist idazoxan has been shown to also recognize with high affinity nonadrenoceptor sites (I2-imidazoline sites). In contrast, the 2-methoxy derivative of idazoxan, 2-methoxy idazoxan (RX821002), binds almost exclusively to alpha-2 adrenoceptors. The purpose of this study was to assess and extend the pharmacological(More)
OBJECTIVE To directly evaluate the guanine nucleotide-binding (G) protein subunits alpha, beta, and gamma, which are involved in the signal transduction of opioid receptors, in the postmortem brains of heroin addicts who had died of an opiate overdose. METHODS Specimens of the frontal cortex (Brodmann's area 9) were collected from 11 heroin addicts and 10(More)
The specific binding of the full agonist [3H] (-) adrenaline to platelet membranes was measured in 14 drug-free depressed patients with melancholia. There was an increased number of binding sites (Bmax) with the same apparent affinity (KD) for the radioligand, indicating that platelet alpha 2-adrenoceptor density in the high affinity state was increased in(More)
Antiotensin II facilitated in a concentration-dependent manner the potassium-evoked 3H-noradrenaline over-flow from the rabbit hypothalamus. This effect which is probably mediated through presynaptic angiotensin facilitatory receptors on noradrenergic nerve terminals was blocked by the specific angiotensin receptor antagonist, saralasin. These results(More)
Specific binding of 3H-clonidine to alpha 2 adrenoreceptors upon human blood platelet membranes is increased in patients with major depressive disorder (endogenous depression). Specific binding of 3H-yohimbine to the platelet adrenoreceptor is not altered in endogenously depressed patients. Other psychiatric disorders are not associated with alterations in(More)