Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023380 (lethargy)
 5,697 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A protein toxic to mice was isolated from the venom of the Mexican beaded lizard Heloderma horridum horridum by a combination of gel filtration (Sephadex G-75) and ion exchange chromatography (both diethylaminoethyl-cellulose [DE-cellulose] and carboxymethyl-cellulose [CM-cellulose]). The purified polypeptide component has an apparent mol. wt of 25,500 and is composed of approximately 220 amino acid residues. It has an isoelectric point (pI) of 6.8 and its N-terminal amino acid sequence was shown to be: Glu-Ala-Ser-Pro-Lys-Leu-Pro-Gly-Leu-Met-Thr-Ser-Asn-Pro-Asp-Gln-Gln-Thr- Glu-Ile. The sequence has no significant similarity with any other protein previously reported in the literature. Enzymatic activities such as phospholipase, hyaluronidase and proteinase, commonly present in venoms, could not be demonstrated in this protein. Patch-clamp experiments conducted with excitable membranes show no effects on Na+, K+ or Ca2+ ion channels. Among the constant physiological effects observed in mice injected with this toxin are lethargy, partial paralysis of rear limbs and lowering of body temperature, suggesting that it might be a hypothermic toxin. We propose calling this toxin Helothermine.
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PMID:Isolation and characterization of helothermine, a novel toxin from Heloderma horridum horridum (Mexican beaded lizard) venom. 169 19

Rats with a portacaval anastomosis and ligation of the hepatic artery 2 days later were infused for 6 hr with a 10% glucose solution (group I) or the same solution combined with 0.24 M/liter branched-chain amino acids (BCAA, group II). Control animals with portacaval anastomosis and sham-operation (group III) or two sham-operations (group IV) were infused with a 10% glucose solution. The rats were killed by decapitation and indoleamines and amino acids were determined in the brain. Rats with liver ischemia were stuporous at the end of the experiment irrespective of treatment. The concentrations in the cortex of lysine, methionine, phenylalanine, threonine, alanine, glutamine, glycine, histidine, and tyrosine were significantly increased in group I compared to group IV. Infusion of BCAA to rats with liver-ischemia (group II) resulted in significantly lower concentrations of lysine, methionine, phenylalanine, threonine, histidine and tyrosine and increased concentrations of isoleucine, leucine, valine, and arginine compared to group I. The content of serotonin in the cortex and brain stem was significantly increased in group I compared with the BCAA-treated animals (group II) and the control groups III and IV. The concentrations of 5-hydroxyindoleacetic acid (5-HIAA) in the cortex and brain stem were higher in group I than in group IV. Infusion of BCAA to rats with liver ischemia normalized the concentrations of 5-HIAA in the cortex and brain stem.
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PMID:Amino acids and indoleamines in the brain after infusion of branched-chain amino acids to rats with liver ischemia. 242 87

A review is presented of 22 published cases of verified or probable mitochondrial 2-methylacetoacetyl-CoA thiolase deficiency, a disorder of isoleucine and ketone body metabolism. The clinical expression, characterized by ketoacidosis, vomiting and lethargy, is highly variable. Typical age of onset is between 6 and 24 months. The disorder, which has been observed in several ethnic groups, is apparently inherited as an autosomal, recessive trait. The prognosis is relatively good if acute episodes of ketoacidosis and dehydration are adequately treated. There is abnormal urinary excretion of 2-methyl-3-hydroxybutyric acid, tiglylglycine, and in some instances also 2-methyl-acetoacetic acid. However, such a pattern of organic aciduria has also been found in cases with normal thiolase activity. Genetic complementation analyses have demonstrated considerable heterogeneity. The cDNA for human methyl-acetoacetyl-CoA thiolase has been cloned and sequenced. Studies in one patient showed a G-to-A substitution at position 1138 of the mRNA, causing 347Ala to Thr change in the mature enzyme. Studies in other patients have shown variable enzyme amount and/or stability.
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PMID:Mitochondrial 2-methylacetoacetyl-CoA thiolase deficiency: an inborn error of isoleucine and ketone body metabolism. 848 3

Calcineurin is a Ca(2+)-calmodulin-dependent serine/threonine protein phosphatase that has been implicated in various signaling pathways. Here we report the identification and characterization of calcineurin genes in Caenorhabditis elegans (cna-1 and cnb-1), which share high homology with Drosophila and mammalian calcineurin genes. C. elegans calcineurin binds calcium and functions as a heterodimeric protein phosphatase establishing its biochemical conservation in the nematode. Calcineurin is expressed in hypodermal seam cells, body-wall muscle, vulva muscle, neuronal cells, and in sperm and the spermatheca. cnb-1 mutants showed pleiotropic defects including lethargic movement and delayed egg-laying. Interestingly, these characteristic defects resembled phenotypes observed in gain-of-function mutants of unc-43/Ca(2+)-calmodulin-dependent protein kinase II (CaMKII) and goa-1/G(o)-protein alpha-subunit. Double mutants of cnb-1 and unc-43(gf) displayed an apparent synergistic severity of movement and egg-laying defects, suggesting that calcineurin may have an antagonistic role in CaMKII-regulated phosphorylation signaling pathways in C. elegans.
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PMID:Calcineurin, a calcium/calmodulin-dependent protein phosphatase, is involved in movement, fertility, egg laying, and growth in Caenorhabditis elegans. 1222 Nov 32

Arousal and maintenance of a wake state is dependent on the hypothalamic hypocretin/orexin system. We found that hypocretin neurons are depressed by opiates, drugs of abuse that reduce cognitive alertness. Met-enkephalin (mENK), an endogenous opioid, and exogenous opiates such as morphine inhibited the hypocretin system by direct actions on the cell body that include reduced spike frequency, hyperpolarization, increased G-protein-coupled inwardly rectifying K(+) channel current, and attenuated calcium current, and indirectly through reducing excitatory synaptic tone by a presynaptic mechanism. CTAP (H-d-Phe-Cys-Tyr-d-Trp-Arg-Thr-Pen-Thr-NH(2)) and naloxone, antagonists of mu-opioid receptors, blocked mu agonist actions. In the absence of exogenous opioids, mu receptor antagonists enhanced activity of the hypocretin system, suggesting ongoing inhibition by endogenous receptors. Morphine pretreatment attenuated subsequent excitatory responses to hypocretin, suggesting a long-lasting depression caused by opiate exposure. Chronic exposure to morphine reduced subsequent responses to morphine and to mENK, but increased the response to opioid receptor antagonists. Together, these data are consistent with the view that the hypocretin system may be an important direct target for drugs of abuse, including opiates, that induce sedation and mental lethargy.
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PMID:Mu-opioid receptor-mediated depression of the hypothalamic hypocretin/orexin arousal system. 1833 11

Citrin deficiency is a common congenital metabolic defect not only in East Asian populations but also in other populations around the world. It has been shown that although liver transplantation is ultimately required in many patients to prevent neurological decompensation associated with hyperammonaemia, arginine is effective in lowering ammonia in hyperammonaemic patients, and a high-protein low-carbohydrate diet may provide some benefit to infants in improving failure to thrive. In the present study, the clinical symptoms and laboratory findings are reported for a 13-year-old citrin-deficient girl in the early stage of adult-onset type II citrullinaemia (CTLN2), and the therapeutic effect of orally administered arginine and sodium pyruvate was investigated. The patient complained of anorexia, lethargy, fatigue and poor growth, and showed laboratory findings typical of CTLN2; elevated levels of plasma citrulline, threonine-to-serine ratio, and serum pancreatic secretory trypsin inhibitor. Oral administration of arginine and sodium pyruvate for over 3 years improved her clinical symptoms and has almost completely normalized her laboratory findings. It is suggested that the administration of arginine and sodium pyruvate with low-carbohydrate meals may be an effective therapy in patients with citrin deficiency in order either to prolong metabolic normalcy or to provide a safer and more affordable alternative to liver transplantation.
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PMID:Treatment of a citrin-deficient patient at the early stage of adult-onset type II citrullinaemia with arginine and sodium pyruvate. 1895 81