Serotonin is a modulatory neurotransmitter in the human brain that regulates mood, anger, reward, aggression, and appetite and plays a central role in brain development. These effects are mediated through the interaction of serotonin with at least 15 different receptor molecules. Through the development and careful characterization of novel radiotracers, we have been able to visualize and quant...

Serotonin acts on 5-hydroxytryptamine (5-HT)1B-like receptors in isolated rabbit ear artery precontracted with phenylephrine (PHE). These receptors are inactive, or "silent," in untreated vessels. Ear artery rings were mounted in tissue baths for the measurement of isometric contraction to further characterize these 5-HT1B-like receptors. The 5-HT1-selective receptor agonist sumatriptan failed ...

BACKGROUND Hereditary tyrosinemia type 1 (HT1; MIM 276700) is caused by mutations in the fumarylaceto-acetate hydrolase (FAH) gene, and is the most severe disorder associated with the tyrosine catabolic pathway. HT1 is a very rare disorder and no genetically confirmed case of HT1 in Korea has yet been reported. In this study, we present a Korean neonate with clinical and biochemical features of...

Hereditary Tyrosinemia type 1 (HT1) is a metabolic liver disease caused by genetic defects of fumarylacetoacetate hydrolase (FAH), an enzyme necessary to complete the breakdown of tyrosine. The severe hepatic dysfunction caused by the lack of this enzyme is prevented by the therapeutic use of NTBC (2-[2-nitro-4-(trifluoromethyl)benzoyl] cyclohexane-1,3-dione). However despite the treatment, chr...

BACKGROUND The antiepileptic drug lamotrigine is effective in the treatment of focal epilepsies. It is thought to act by inhibition of glutamate release through blockade of voltage-sensitive sodium channels and stabilization of the neuronal membrane. Lamotrigine is also effective in the treatment of mood disorders such as bipolar disorder. However, its exact mechanism of action in these conditi...

Fasting gastric fundus tone is maintained by continuous cholinergic input. 5-Hydroxytryptamine-1 (5-HT1) receptor activation decreases gastric fundus tone in humans. Whether this fundus-relaxing effect is mediated via inhibition of cholinergic input or via activation of a nitrergic pathway is unknown. The aim of the present study was to determine the effect of nitrergic inhibition on feline gas...

In this study, [1251]iodocyanopindolol ([125I]ICYP), in the presence of isoproterenol, was used to label 5-hydroxytryptaminelB (5HTIB) receptors in homogenates of the cortex, substantia nigra and caudate-putamen of the rat. The determination of the appropnate concentrations of isoproterenol required to block optimally beta adrenoceptors whereas producing minimal occupancy of 5HT1B receptors was...

Plasma osmolality alters control of sympathetic activity and heart rate in animal models; however, it is unknown whether physiological increases in plasma osmolality have such influences in humans and what effect concurrent changes in central venous and/or arterial pressures may have. We tested whether physiological increases in plasma osmolality (similar to those during exercise dehydration) a...

Diabetic neuropathic pain, an important micro vascular complication in diabetes mellitus, has been recognized as one of the most difficult types of pain to treat. Lack of understanding of etiology involved, inadequate relief, development of tolerance and potential toxicity of classical anti-nociceptive agents warrants the investigation of newer agents to relieve this pain. The aim of the presen...

Background. Platelets release two powerful vasoconstrictors thromboxane A2 (TXA2) and 5-hydroxytryptamine (5-HT). Animal studies have suggested that these two substances may act in a synergistic fashion to stimulate platelet activity and smooth muscle vasoconstriction. Methods and Results. To assess the interaction between TXA2 and 5-HT at the individual 5--HT receptor subtypes reported to medi...