Serotonin isolation

Wlien C -labeled tryptamine was administered to rabbits, the serotonin isolated from platelets, stomach, and intestine was found to be devoid of... 

Rapport MM, Green AA, Page H. Serum vasoconstrictor, serotonin isolation and characterization. / Biol Chem. 

Lesch, K. R et al. (1993). Isolation of a cDNA encoding the human brain serotonin transporter. /. Neural Transm. Gen. Sect., 91, 67-72. 

In regard to the experimental evidence available, a substantial number of reports on the chemical constituents of the plant are available, but much less work has been done with the pharmacological properties. Kasture et al., however, made the important observation that a triterpene isolated from R. cordifolia induces anxiety in rodents, an effect accompanied with an increase in serotonin contents in the brain (30). An interesting development from that observation would be to explore further the molecular-pharmacological pathway and the effect of this agent on the serotoninergic system because terpenes, compared with indole alkaloids, are seldom reported for serotoninergic activities. 

Autonomic effects Harmala alkaloids, as well as isolated harmine and harmaline, produce a dose-dependent hypothermia (Abdel-Fattah et al. 1995). This effect is serotonin-dependent, and partly mediated by 5-HTlA receptors. 

Several natural products have been evaluated in rodent models of nicotine withdrawal. An extract of Hypericum perforatum (St. John s Wort, a putative antidepressant, and inhibitor of serotonin reuptake) reversed somatically expressed withdrawal behaviors and locomotor depression in spontaneous withdrawal (Catania et al. 2003). A benzoflavone compound isolated from Passiflora incarnata, interfered with the induction of physical dependence. Coadministration with chronic nicotine prevented various subsequent indicators of withdrawal syndrome in the mouse, including jumping, locomotor inactivity, immobility in the swim test and naloxone-precipitated escape jumping (Dhawan et al. 2002). 

To date, at least four major subtypes of serotonin receptor have been described in detail and a major advance has been made with the isolation of genomic clones for these receptor subtypes. We now await the further development of selective ligands for all the serotonin receptor subtypes which may ultimately lead to a better understanding of the functional significance and clinical relevance of serotonin receptors in health and disease. Hopefully such a development will also result in the availability of more effective drugs to treat neurological and psychiatric diseases. 

The regulation of calcitonin synthesis and release from the parafollicular C cells of the thyroid gland is calcium dependent. Rising serum calcium is the principal stimulus responsible for calcitonin synthesis and release. Other hormones, such as glucagon, gastrin, and serotonin, also stimulate calcitonin release. Calcitonin has been isolated in tissues other than the parafollicular C cells (parathyroid, pancreas, thymus, adrenal), but it is not known whether this material is biologically active. 

Maurice M. Rapport, Arda Alden Green, and Irvine H. Page of the Cleveland Clinic foundation in Ohio isolate and name the chemical serotonin, which they discover in the blood. 

Murasaki M, Mori A, Endo S, et al Late phase 2 study of a new anxiolytic SM-3997 (tandospirone) on neurosis. Clinical Evaluation 20 259-293, 1992 Murase K, Randic M, Shirasaki T, et al Serotonin suppresses N-methyl-D-aspartate responses in acutely isolated spinal dorsal horn neurones of the rat. Brain Res 525 84-91, 1990... 

Norbufotenine (5-hydroxy-N-methyltryptamine, N-methylserotonin, 5-OH-NMT) This base is scattered in both the animal and the plant kingdoms. It has been found in quite a few toads and in barley shoots. It has been isolated from the herb Desmodium pulchellum. This is an interesting twilight compound lying halfway between a notorious toxin (bufotenine) and a vital neurotransmitter (serotonin). And it is unexplored, for shame. It has been detected in the urine... 

To measure serotonin (5-hydroxytryptamine), by the internal standard method, a 1 ml aliquot of the unknown solution is added to 1 ml of a solution containing 30 ng of N-methyl-serotonin. This mixture is then treated to remove all other compounds which could interfere with the experiment. The operation performed was an extraction in the solid phase to isolate the serotonin and its methyl derivative, diluted in a suitable medium. 

Specific decarboxylases for most of the common amino acids have been isolated. In mammals, a decarboxylase involved in the biosynthesis of neuroactive amines is particularly important. This enzyme decarboxylates 3,4-dihydroxyphenylalanine and 5-hydroxytryp-tophan (both products of tetrahydrobiopterin-dependent hydroxylations—Section 1.10.5.1) to give 3,4-dihydroxyphenethylamine and serotonin (equation 10), respectively (70MI11002). 

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