The data obtained in this study demonstrate that the concentration of serotonin is markedly elevated (18- to 27-fold) at the site of a coronary arterial stenosis in open-chest, anesthetized dogs with cyclic flow variations. Cyclic flow variations in this experimental preparation were abolished by ketanserin, a 5-hydroxytryptamine antagonist, but serotonin concentration at the site of the corona...

The new selective 5-HT2 receptor blocking agent ketanserin was given in a dose of 10 mg intravenously to 12 patients with essential hypertension. It caused a distinct fall in supine systemic arterial, right atrial, pulmonary artery, and pulmonary capillary "wedge" pressures. Cardiac output, renal blood flow, and glomerular filtration rate showed no persistent changes. Thus 5-HT2 receptor blocka...

PURPOSE The aim of this study was to assess the potential involvement of a specific subtype of 5-hydroxytryptamine (5-HT), 5HT2 receptors in neurally-induced contractions of the human detrusor. METHODS Contractile responses to electrical field stimulation (EFS) were examined in human isolated urinary bladder muscle strips. The potentiation of EFS-induced detrusor contraction was examined by a...

BACKGROUND Salvinorin-A is a terpene found in the leaves of the plant Salvia divinorum. When administered to humans, salvinorin-A induces an intense but short-lasting modified state of awareness, sharing features with those induced by the classical serotonin-2A receptor agonist psychedelics. However, unlike substances such as psilocybin or mescaline, salvinorin-A shows agonist activity at the k...

5-hydroxytryptamine (5-HT) released in inflammatory tissues plays a pivotal role in pain hypersensitivity. However, it is not clear whether 5-HT2A receptors in the inflamed tissues mediate this effect. The present study investigated the contribution of 5-HT2A receptors in the periphery to chronic inflammatory pain. Complete Freund's adjuvant (CFA) was injected subcutaneously in the hindpaw of r...

Background. Serotonin, released by aggregating platelets, may contribute to or cause myocardial ischemia by constricting epicardial vessels. Experimental studies suggest that this constriction is mediated by two distinct serotonin receptor subtypes: 5-hydroxytryptaminel-like (S,-like) and 5-hydroxytryptamine2 (S2). Methods and Results. To determine the relative contribution of S,-like and S2 re...

Exposure of sensitised intestine to specific allergen is known to produce appreciable reduction in water and electrolyte absorption. The mediators participating in this process have not been fully characterised. The effects of the 5-hydroxytryptamine2 (5-HT2) and 5-HT3 receptor antagonists, ketanserin and granisetron, respectively, on water movement during intestinal anaphylaxis were studied. H...

Due to the stimulatory action of serotonin (5HT) and nitric oxide (NO) on the secretion of gonadotropins and PRL, this work aimed at investigating the participation of serotoninergic receptors 5HT(1) and 5HT(2) of the medial preoptic area (MPOA) in the control of luteinizing hormone (LH), follicle stimulating hormone (FSH) and prolactin (PRL) secretion and the possible modulation by ovarian ste...

BACKGROUND Serotonin, released by aggregating platelets, may contribute to or cause myocardial ischemia by constricting epicardial vessels. Experimental studies suggest that this constriction is mediated by two distinct serotonin receptor subtypes: 5-hydroxytryptamine1-like (S1-like) and 5-hydroxytryptamine2 (S2). METHODS AND RESULTS To determine the relative contribution of S1-like and S2 re...