Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0241981 (loss of balance)
 452 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The GABAergic agonist, muscimol, and antagonists, picrotoxin and bicuculline, have been studied in rats with chronic portacaval shunts and in rats developing hepatic encephalopathy after massive ischemic necrosis due to hepatic artery ligation within 48 hr of a portacaval shunt. After the chronic portacaval shunt and to a lesser extent in normal rats intraventricular muscimol resulted in chewing and eating behavior, ataxia and loss of balance that lasted 2 to 3 hr. Lethargy, stupor and coma did not occur. Intraventricular saline had no effect. Bicuculline i.p. lessened the effects of the muscimol. In rats developing hepatic encephalopathy, intraventricular muscimol shortened the time to precoma and coma by approximately 40%. Bicuculline i.p. counteracted this effect of muscimol significantly. However, neither bicuculline nor picrotoxin given alone altered the times to precoma (Stage III), coma (Stage IV) or death. While hepatic encephalopathy in this experimental model is susceptible to GABAergic effects, its natural progression does not appear to be due to GABA.
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PMID:In vivo studies of GABAergic effects in experimental hepatic encephalopathy. 375 44

The central nervous system is severely affected by hypoxic conditions, which produce alterations in neural cytoarchitecture and neurotransmission, resulting in a variety of neuropathological conditions such as convulsive states, neurobehavioral impairment and motor CNS alterations. Some of the neuropathologies observed in hypobaric hypoxia, corresponding to high altitude conditions, have been correlated with a loss of balance between excitatory and inhibitory neurotransmission, produced by alterations in glutamatergic and GABAergic receptors. In the present work, we have studied the effect of chronic hypobaric hypoxia (506 hPa, 18 h/day x 21 days) applied to adult male mice on GABA(A) receptors from cerebral cortex, to determine whether hypoxic exposure may irreversibly affect central inhibitory neurotransmission. Saturation curves for [3H]GABA specifically bound to GABA(A) receptors in isolated synaptic membranes showed a 30% decrease in maximal binding capacity after hypoxic exposure (Bmax control, 4.70+/-0.19, hypoxic, 3.33+/-0.10 pmol/mg protein), with no effect on GABA binding sites affinity (Kd control: 159.3+/-13.3 nM, hypoxic: 164.2+/-15.1 nM). Decreased B(max) values were observed up to the 10th post-hypoxic day, returning to control values by the 15th post-hypoxic day. Pharmacological properties of GABA(A) receptor were also affected by hypoxic exposure, with a 45 to 51% increase in the maximal effect by positive allosteric modulators (pentobarbital and 5alpha-pregnan-3alpha-ol-20-one). We conclude that long-term hypoxia produces a significant but reversible reduction on GABA binding to GABA(A) receptor sites in cerebral cortex, which may reflect an adaptive response to this sustained pathophysiological state.
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PMID:Prolonged exposure to hypobaric hypoxia transiently reduces GABA(A) receptor number in mice cerebral cortex. 1124 12