Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042963 (vomiting)
 31,883 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mammalian tachykinins (substance P, neurokinin A, and neurokinin B) are widely distributed throughout the central and peripheral nervous systems, where they act as neurotransmitters or neuromodulators. Historically, the tachykinins have been implicated in a wide variety of biological actions such as pain transmission, neurogenic inflammation, smooth muscle contraction, vasodilation, secretion, and activation of the immune system. Their effects are mediated via specific G-protein-coupled receptors (NK1, NK2, and NK3 receptors). The development of nonpeptide receptor antagonists revealed species differences in neurokinin-receptor pharmacology, and the recent cloning of human neurokinin receptors has led to development of compounds with optimized affinity for the human target receptor. The neurokinin-receptor antagonists have been used in preclinical experiments to confirm the physiological roles of the tachykinins. Importantly, it is now recognised that these agents can inhibit the actions of tachykinins released from peripheral nerves, and for the NK1-receptor antagonists (the most widely studied class of neurokinin-receptor antagonists) central sites of action have also been demonstrated. These studies support the development of neurokinin-receptor antagonists as potentially exploitable drug therapies in humans, particularly in the treatment of pain and emesis.
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PMID:Neurokinin-receptor antagonists: pharmacological tools and therapeutic drugs. 927 38

After its discovery in 1931, substance P (SP) remained the only mammalian member of the family of tachykinin peptides for several decades. Tachykinins thus refer to peptides sharing the common C-terminal amino acid sequence Phe-X-Gly-Leu-Met x NH2. In recent years the family of mammalian tachykinins has grown with the isolation of two novel peptides from bovine and porcine central nervous system (CNS), neurokinin A and neurokinin B. In parallel with the identification of multiple endogenous tachykinins several classes of tachykinin receptors were discovered. The receptors described so far are named tachykinin NK1 receptor, tachykinin NK2 receptor and tachykinin NK1 receptor, respectively. The present review focuses on the pharmacology and putative function of tachykinin NK1 receptors in brain. The natural ligand with the highest affinity for the tachykinin NK1 receptor is SP itself. The C-terminal sequence is essential for activity, the minimum length of a fragment with reasonable affinity for the tachykinin NK1 receptor is the C-terminal hexapeptide. A rapid advance of knowledge was caused by development of non-peptidic tachykinin NK1 receptor antagonists. This area is under rapid development and a variety of different chemical classes of compounds are involved. Species-dependent affinities of tachykinin NK1 receptor antagonists reveal two clusters of compounds, targeting the tachykinin NK1 receptor subtype found in guinea pig, human or ferret or the one in rat or mouse, respectively. The most recently developed compounds are highly selective, enter the brain and are orally bioavailable. Distinct behavioural effects in experimental animals suggest the involvement of tachykinin NK1 receptors in nociceptive transmission, basal ganglia function or anxiety and depression. Recent clinical trials in man showed that tachykinin NK1 receptor antagonists are effective in treating depression and chemotherapy-induced emesis. Therefore, it is well possible that tachykinin NK1 receptor antagonists will be clinically used for treatment of specific CNS disorders within a short period of time.
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PMID:The tachykinin NK1 receptor in the brain: pharmacology and putative functions. 1044 64

The classical tachykinins, substance P, neurokinin A and neurokinin B are predominantly found in the nervous system where they act as neurotransmitters and neuromodulators. Their respective preferred receptors are NK1, NK2, and NK3 receptors. The presence of substance P in nociceptive primary afferent neurons, electrophysiological studies showing that it activated neurons in the dorsal horn of the spinal cord, and behavioral studies in animals, supported the concept that substance P was an important transmitter in the nociceptive pathway. It was therefore surprising that non-peptide NK1 receptor antagonists were ineffective as analgesics in clinical pain conditions. Nevertheless, the discovery that NK1 receptor antagonists had antidepressant activity led to renewed interest in these antagonists. It is disappointing that clinical trials of MK869 (aprepitant) for depression were suspended. The future of NK1 receptor antagonists as antidepressant drugs will depend on the outcome of clinical trials with other NK1 receptor antagonists. NK1 receptor antagonists were also found to be effective antiemetics, and aprepitant has recently become available for the treatment of chemotherapy induced emesis. Although less is known of the potential of NK2 and NK3 receptor antagonists, recent trials of NK3 receptor antagonists have shown efficacy in schizophrenia. The discovery of a new family of tachykinins, the hemokinins and endokinins, which acts on NK1 receptors and has potent effects on immune cells, has implications for the clinical use of NK1 receptor antagonists. Thus specific therapeutic strategies may be required to enable NK1 receptor antagonists to be introduced for treatment of neuropsychiatric disorders.
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PMID:Tachykinins and neuropsychiatric disorders. 1691 27