Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The vanilloid receptor VR1 is a nonselective cation channel activated by capsaicin as well as increases in temperature and acidity, and can be viewed as molecular integrator of chemical and physical stimuli that elicit pain. The distribution of VR1 receptors in peripheral and central processes of rat primary vagal afferent neurons innervating the gastrointestinal tract was investigated by immunohistochemistry. Forty-two percent of neurons in the nodose ganglia retrogradely labeled from the stomach wall expressed low to moderate VR1 immunoreactivity (VR1-IR). VR1-IR was considerably lower in the nodose ganglia as compared to the jugular and dorsal root ganglia. In the vagus nerve, strongly VR1-IR fibers ran in separate fascicles that supplied mainly cervical and thoracic targets, leaving only weakly VR1-IR fibers in the subdiaphragmatic portion. Vagal afferent intraganglionic laminar endings (IGLEs) in the gastric and duodenal myenteric plexus did not express VR1-IR. Similarly, VR1-IR was contained in fibers running in perfect register with vagal afferents, but was not colocalized with horseradish peroxidase in the same varicosities of intramuscular arrays (IMAs) and vagal afferent fibers in the duodenal submucosa anterogradely labeled from the nodose ganglia. Only in the gastric mucosa did we find evidence for colocalization of VR1-IR in vagal afferent terminals. In contrast, many nerve fibers coursing through the myenteric and submucosal plexuses contained detectable VR1-IR, the majority of which colocalized calcitonin gene-related peptide immunoreactivity. In the dorsal medulla there was a dense plexus of VR1-IR varicose fibers in the commissural, dorsomedial and gelatinosus subnuclei of the medial NTS and the lateral aspects of the area postrema, which was substantially reduced, but not eliminated on the ipsilateral side after supranodose vagotomy. It is concluded that about half of the vagal afferents innervating the gastrointestinal tract express low levels of VR1-IR, but that presence in most of the peripheral terminal structures is below the immunohistochemical detection threshold.
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PMID:Vanilloid receptor (VR1) expression in vagal afferent neurons innervating the gastrointestinal tract. 1265 36

Autoimmune dysfunction of certain vasoactive neuropeptides (VNs) has been postulated as a contributing cause of sudden infant death syndrome (SIDS), chronic fatigue syndrome (CFS), Gulf War syndrome (GWS) and other fatigue-related disorders. This family of VNs includes pituitary adenylate cyclase activating polypeptide (PACAP), vasoactive intestinal peptide (VIP) and calcitonin gene related peptide (CGRP). The postulated mechanism is compromise of adenylate cyclase activation, a vital and unique step in cyclic AMP production from ATP, through autoimmune dysfunction of VNs, their receptors or their genes possibly involving cytosine-phosphate-guanine (CpG) fragments. CpG fragments are immunomodulatory dinucleotides serving as 'friend or foe' recognition systems to differentiate bacterial and viral (hypomethylated CpG) from mammalian (methylated CpG) DNA. However hypomethylation disorders affecting these fragments in mammals may convert them to dysfunctional states by promoting autoimmune inflammatory reactions. Epigenetic mechanisms acting on gene promoter regions may contribute to the development of VN autoimmune fatigue-related disorders through CpG fragments located in vital segments of VN/receptor genes by causing signalling defects with profound implications for VN function. Neurotransmitter dysfunction particularly glutamatergic transmission could also result with disruption of neuronal cellular biochemical functions such as ammonia regulation. Endosomal acidity and mitochondrial membrane potential modifiers such as chloroquine, together with immunoregulatory therapies, may have therapeutic implications in protecting against these apparent autoimmune disorders. This paper examines specific epigenetic and biochemical mechanisms possibly mediated by VN or receptor genes resulting in postulated VN autoimmune fatigue-related disorders. These mechanisms may have implications for treatment and prevention options for VN autoimmune disorders. VN autoimmune processes have implications for military medicine where radiological, chemical and biological agents may play an important role in pathogenesis.
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PMID:Does dysregulation of key epigenetic and biochemical pathways occur in postulated vasoactive neuropeptide autoimmune disorders? 1602 37


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