We quantified the binding potentials (BPND) of [(11)C]yohimbine binding in rat brain to alpha-2 adrenoceptors to evaluate [(11)C]yohimbine as an in vivo marker of noradrenergic neurotransmission and to examine its sensitivity to the level of noradrenaline. Dual [(11)C]yohimbine dynamic positron emission tomography (PET) recordings were applied to five Sprague Dawley rats at baseline, followed b...

Antibodies were raised against a newly synthesized analog (CP57,609) of the alpha 1-selective antagonist prazosin, and against the alpha 2-selective antagonist, yohimbine, by immunization of rabbits with antigens prepared by covalent linkage of these ligands to albumin. Competitive inhibition of [3H]prazosin binding to anti-CP57,609 antiserum by a variety of unlabeled ligands revealed a spectru...

BACKGROUND "Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder associated with ovulatory dysfunction". "Autonomic and central nervous systems play important roles in the regulation of ovarian physiology". The noradrenergic nucleus locus coeruleus (LC) plays a central role in the regulation of the sympathetic nervous system and synaptically connected to the preganglio...

Menegaz, Rubia G., Daniel R. Kapusta, Antonio M. Cabral. Role of intrarenal a2-adrenoceptors in the renal responses to xylazine in rats. Am J Physiol Regulatory Integrative Comp Physiol 278: R1074–R1081, 2000.—This study examined the contribution of intrarenal a2-adrenoceptor mechanisms to the enhanced urine flow rate (V) and urinary sodium excretion (UNaV) responses in ketaminexylazine-anesthe...

We studied the influence of the alpha 2-adrenoreceptor-blocking drug, yohimbine, on blood pressure, plasma norepinephrine, and other measures of autonomic function in normal male volunteers. These studies were designed to evaluate the role of alpha 2-receptors in the tonic regulation of sympathetic outflow in humans. In a dose-ranging study, we found that yohimbine HCl (0.016-0.125 mg/kg) elici...

This study examined the effects of the nitric oxide-precursor L-arginine combined with the alpha 2-blocker yohimbine on subjective and physiological sexual arousal in postmenopausal women with Female Sexual Arousal Disorder. Twenty-four women participated in three treatment sessions in which self-report and physiological (vaginal photoplethysmograph) sexual responses to erotic stimuli were meas...

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used in pain whose mechanism of action is the inhibition cyclooxygenase enzymes (COXs), however, there evidence other mechanisms action, such as substance P, interaction with systems NO, monoaminergic and others. The objective present work was to study participation a-1 (prazosin) a-2 (yohimbine) adrenoceptors antagonists antinociception...

introduction: estrogen and progesterone are supposed to modify pain sensitivity. however, the actual role of each of these steroid hormones in this respect is not well known. plasma concentrations of these hormones show variation during estrous cycle. the role of alpha2 receptors in tonic pain has been pointed out. the aim of the present study was to investigate the agonist and antagonist effec...

BACKGROUND The role of noradrenergic system in the control of nociception is documented in some vertebrate animals. However, there are no data showing the role of this system on nociception in the marsh terrapins. METHODOLOGY In this study, the antinociceptive action of intrathecal administration of the α 2-adrenoreceptor agonist clonidine and α 2-adrenoreceptor antagonist yohimbine was evalu...