RATIONALE AND OBJECTIVES There is evidence that drug addiction is associated with increased physiological and psychological responses to stress. In this pilot functional magnetic resonance imaging (fMRI) study we assessed whether a prototype behavioral addiction, pathological gambling (PG), is likewise associated with an enhanced response to stress. METHODS We induced stress by injecting yohi...

The potassium (K+)-induced release of endogenous norepinephrine from the coccygeal artery of spontaneously hypertensive rats has been studied as a function of the development of hypertension. The absolute amount of norepinephrine released by potassium was greater in spontaneously hypertensive rat than the normotensive Wistar-Kyoto rat, regardless of age or blood pressure. However, the %-fractio...

OBJECTIVE Increases in adrenergic activity are associated with stress, anxiety, and other psychiatric, neurological, and medical disorders. To improve understanding of normal CNS adrenergic function, CBF responses to adrenergic stimulation were determined. METHODS Using PET, the CBF changes after intravenous yohimbine, an alpha2-adrenoreceptor antagonist that produces adrenergic activation, w...

Rauwolfia species (Apocynaceae) are medicinal plants well known worldwide due to its potent bioactive monoterpene indole alkaloids (MIAs) such as reserpine, ajmalicine, ajmaline, serpentine and yohimbine. Reserpine, ajmalicine and ajmaline are powerful antihypertensive, tranquilizing agents used in hypertension. Yohimbine is an aphrodisiac used in dietary supplements. As there is no report on t...

in this study, the effect of α-adrenoceptor agents on imipramine-induced antinociception was investigated using formalin test. intraperitoneal (i.p.) administration of imipramine at different doses (10-80 mg/kg) induced antinociception in both phases of formalin test. in addition, intracerebroventricular (i.c.v.) injection of imipramine (1, 5, and 10 µg/rat) did not elicit any effect, although ...

The purpose of this study was to determine whether both alpha 1- and alpha 2-adrenergic receptors exist on vascular smooth muscle of microvessels and whether adrenergic constriction of anatomically distinct microvascular segments is differentially subserved by either receptor subtype. The cremaster skeletal muscle of anesthetized rats was acutely denervated and suspended in a Krebs bath contain...

Juvenile spontaneously hypertensive rats (SHR) have higher plasma levels of catechols and markedly larger catechol responses to yohimbine than do normotensive Wistar-Kyoto rats, indicating increased sympathoadrenal outflow and increased o^-adrenergic receptor-mediated restraint of peripheral catecholamine release during hypertension development in SHR. Yohimbine-induced catecholamine release an...