Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.9.3.1 (cytochrome oxidase)
 8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A case of mitochondrial encephalomyopathy (Kearns-Sayre syndrome) with corneal endothelial abnormality is reported. A 22-year-old woman had retinitis pigmentosa, external ophthalmoplegia, complete heart block, ataxia, muscle weakness, dementia, sensorineural hearing loss, and was of short stature. Renal dysfunction, diabetes mellitus, and amenorrhea were also observed. Biopsy revealed decreased cytochrome c oxidase (complex IV) activity in muscle mitochondria. The corneal endothelium examined by specular microscope showed decreased cell density, severe polymegathism, and pleomorphism in both eyes. To our knowledge, this is the first report concerning primary corneal endothelial abnormality in a case with mitochondrial encephalomyopathy. The corneal endothelium is one of the tissues that could be affected by the enzyme deficiency present in this disease.
Cornea 1989 Sep
PMID:Corneal endothelium in a case of mitochondrial encephalomyopathy (Kearns-Sayre syndrome). 274 82

Proper corneal hydration is normally maintained by a pump-leak mechanism located on the lateral cell membranes of the endothelium (1,2). When endothelial cells become sufficiently dysfunctional in response to trauma, the cornea becomes irreversibly edematous and opaque. Previous studies in our laboratory have shown that mitochondrial cytochrome oxidase (CO) activity, an enzyme important in respiratory activities, is correlated with endothelial cell functional activity in corneas with Fuchs' endothelial dystrophy. In this study we investigated cytochrome oxidase activity in corneas with postsurgical bullous keratopathy. Corneas with aphakic and pseudophakic bullous keratopathy (ABK, PBK) were incubated in diaminobenzidine-cytochrome C media. Results showed that the staining pattern of ABK and PBK corneas was uniformly low compared to keratoconus corneas, and in contrast to previous studies on Fuchs' dystrophy corneas which demonstrated a regional staining pattern. This suggests that CO staining patterns correlate with functional activity and may be a useful technique to detect dysfunctional cells in various disease categories.
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PMID:Cytochrome oxidase activity of postsurgical bullous keratopathy endothelium. 282 57

The acute toxicity of cyanide is largely due to the inhibition of cytochrome oxidase, and the subsequent breakdown of cellular metabolism. Breakdown in cellular metabolism, leading to a disruption of cellular integrity lies at the heart of the permanent neurological damage resulting from ischemic/hypoxic brain insult. In 200 g male Wistar rats treated with 5 mg/kg KCN i.v. and ventilated until spontaneous breathing restarted, the cornea reflex, tail-pinch reaction and righting reflex disappeared for about 20 min. In curarized and artificially ventilated rats the EEG remained flat for a similar period before slowly returning. Saline treated animals which survive the KCN injection die significantly earlier than non-KCN treated animals when injected with 120 mg/kg metrazol s.c. one week later. Histological examination of KCN treated animals revealed swollen mitochondria at 20 min, and microvacuolization and ischemic cell changes at 1 week. In rats pretreated with etomidate 10 mg/kg s.c. 30 min before cyanide the cornea, tail-pinch and righting reflex were absent for the same time as in controls. The EEG was similar to that seen in saline/KCN animals, however, the time to EEG was similar to that seen in saline/KCN animals, however, the time to EEG silence was doubled. One week after the cyanide injection their reaction to the metrazol injection was similar to animals treated one week earlier with saline. Although there was evidence of swollen mitochondria 20 min after KCN, one week after KCN there was no evidence of ischemic hypoxic brain damage. These results demonstrate that under similar conditions of dysoxia, etomidate treated animals appear to be protected from the behavioural and histological sequelae of those conditions.
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PMID:Behavioural, electroencephalographic and histological study of the protective effect of etomidate against histotoxic dysoxia produced by cyanide. 733 99