Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002736 (amyotrophic lateral sclerosis)
 19,048 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this study, we examined the effects of oxidative stress on a nitric oxide (NO)-regulated neuroendocrine function, the release of arginine vasopressin (AVP) by the hypothalamo-neurohypophyseal axis. Treatment of mouse-isolated hypothalami and neurointermediate lobes (NIL) with H2O2 increased AVP release. This effect was inhibited by copper-zinc superoxide dismutase-1 (SOD1) analogs. By measuring cGMP accumulation as an indicator of biologically active NO, we found that H2O2 treatment decreased cGMP formation in both hypothalami and NIL. We have previously shown that NO inhibits AVP release by a cGMP-independent mechanism. Given that H2O2 stimulated AVP release, while it reduced cGMP production, our findings strongly suggest that oxidative damage affects neurosecretion by reducing NO availability. To test whether such a mechanism may operate under pathological conditions with pronounced oxidative stress, we compared neurosecretion in wild-type and transgenic mice carrying a mutated form of SOD1 associated with human familial amyotrophic lateral sclerosis. Reminiscent of the data obtained from H2O2-treated tissues, hypothalami and NIL from SOD1 mutants displayed decreased cGMP accumulation and increased AVP release, compared with tissues from wild-type littermates. Since neuronal NO synthase expression was not modified, we conclude that the perturbed free radical metabolism associated with the SOD1 mutation is likely to trap NO, and thereby alter neurosecretion, a mechanism that can be exacerbated in specific physiopathological conditions.
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PMID:Oxidative stress and a murine superoxide dismutase-1 mutation promoting amyotrophic lateral sclerosis alter neurosecretion in the hypothalamo-neurohypophyseal axis. 1034 79

Amyotrophic lateral sclerosis (ALS) is a fatal, paralytic disorder that primarily affects motoneurons. By combining physiological and morphological approaches, we examined the effect of a murine superoxide dismutase 1 (SOD1) mutation (G86R), which induces neurological disorders resembling human familial ALS (FALS), on the arginine vasopressin (AVP) hypothalamo-neurohypophysial axis, an unmyelinated tract poor in neurofilaments. First, we observed that G86R mice progressively consumed more water than wild-type littermates. Furthermore, levels of plasma AVP and neurohypophysial AVP content were decreased in the SOD1 mutant mice, whereas the amount of hypothalamic AVP increased in an age-dependent manner. However, hypothalamic AVP mRNA levels were not significantly modified in these animals. At the ultrastructural level, we found that the neurohypophysis of G86R mice had a decreased number of neurosecretory axons. Conversely, the presence of large axon swellings was more pronounced in the SOD1 mutant mice. In addition, the size of neurosecretory granules was higher in G86R than in wild-type animals. All these findings strongly suggest that the FALS-associated SOD1 mutation injures the hypothalamo-neurohypophysial axis by provoking early, progressive disturbances in the axonal transport of neurosecretory products from neuronal perikarya to nerve terminals. This blockade could ultimately result in degeneration of the tract, as proposed for the myelinated, neurofilament-enriched motor axons affected by ALS.
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PMID:A mouse model of familial amyotrophic lateral sclerosis expressing a mutant superoxide dismutase 1 shows evidence of disordered transport in the vasopressin hypothalamo-neurohypophysial axis. 1059 43

A 71-year-old man developed dysarthria and difficulty of swallowing in December 1997. He was diagnosed as having the bulbar type of amyotrophic lateral sclerosis (ALS). In November 1998, he was admitted to our hospital to undergo treatment for bulbar palsy and respiratory discomfort. In January 1999, ventilatory support (synchronous intermittent mandatory ventilation) during sleep at night was initiated. Severe progressive hypotension and loss of consciousness were observed soon after the start of artificial respiration, and both symptoms disappeared after artificial respiration was discontinued. This phenomenon was observed consistently during ventilatory support, while unpleasant stimuli such as bronchoscopy and replacement of the cannula tube induced severe hypertension. To clarify the mechanism of underlying these abnormal changes in blood pressure, autonomic function tests were performed while awake during the daytime. Ventilatory support induced a drop in blood pressure accompanied by a decrease in influx speed to the right ventriculum, the latter of which suggested a reduction in venous return. These values returned to the baseline following detachment of the ventilator. A 60 degrees head-up tilt (HUT) angle and standing from a supine position produced orthostatic hypotension, the latter of which was accompanied by a compensatory increase in pulse rate. The basal supine plasma noradrenaline (NA) level was high and the HUT showed a slight elevation of NA. The basal supine plasma arginine vasopressin (AVP) level was within the normal range, whereas the AVP level did not increase during HUT. Urinary secretion rates of NA and 3-methoxy-4-hydroxy-phenylglycol were elevated. A cold pressor test demonstrated reflex hypertension. The oculovagal reflex, coefficient of variation of R-R intervals. (CVR-R) and increase in pulse rate in response to atropine administration were within the normal range. The combination of midodrine, L-dihydroxyphenylserine (DOPS) and increasing intravascular volume via continuous intravenous drip infusion relieved the circulatory collapse during artificial respiration. In conclusion, the present case of ALS had sympathetic hyperactivity, somatosympathetic reflex and dysregulation of the baroreflex arc. Degeneration of central autonomic network, including the hypothalamus and the central nucleus of the amygdala, which has been shown in some ALS patients, might underlie the autonomic abnormalities in this patient.
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PMID:[A case of amyotrophic lateral sclerosis presenting with circulatory collapse during artificial respiration]. 1125 87

The coppery titi monkey (Callicebus cupreus) is a socially monogamous New World primate that has been studied in the field and the laboratory to investigate the behavioral neuroendocrinology of primate pair bonding and parental care. Arginine vasopressin has been shown to influence male titi monkey pair-bonding behavior, and studies are currently underway to examine the effects of oxytocin on titi monkey behavior and physiology. Here, we use receptor autoradiography to identify the distribution of arginine vasopressin 1a receptor (AVPR1a) and oxytocin receptors (OXTR) in hemispheres of titi monkey brain (n=5). AVPR1a are diffuse and widespread throughout the brain, but the OXTR distribution is much more limited, with the densest binding being in the hippocampal formation (dentate gyrus, CA1 field) and the presubiculum (layers I and III). Moderate OXTR binding was detected in the nucleus basalis of Meynert, pulvinar, superior colliculus, layer 4C of primary visual cortex, periaqueductal gray (PAG), pontine gray, nucleus prepositus, and spinal trigeminal nucleus. OXTR mRNA overlapped with OXTR radioligand binding, confirming that the radioligand was detecting OXTR protein. AVPR1a binding is present throughout the cortex, especially in cingulate, insular, and occipital cortices, as well as in the caudate, putamen, nucleus accumbens, central amygdala, endopiriform nucleus, hippocampus (CA4 field), globus pallidus, lateral geniculate nucleus, infundibulum, habenula, PAG, substantia nigra, olivary nucleus, hypoglossal nucleus, and cerebellum. Furthermore, we show that, in the titi monkey brain, the OXTR antagonist ALS-II-69 is highly selective for OXTR and that the AVPR1a antagonist SR49059 is highly selective for AVPR1a. Based on these results and the fact that both ALS-II-69 and SR49059 are non-peptide, small-molecule antagonists that should be capable of crossing the blood-brain barrier, these two compounds emerge as excellent candidates for the pharmacological manipulation of OXTR and AVPR1a in future behavioral experiments in titi monkeys and other primate species.
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PMID:Neuroanatomical distribution of oxytocin and vasopressin 1a receptors in the socially monogamous coppery titi monkey (Callicebus cupreus). 2481 26