Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.1.1 (hexokinase)
 5,274 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Causality of the metrizamide-induced neural adverse effects was explored among the effects on behavior, electroencephalogram (EEG), and brain glucose utilization in rats. Iotrolan, a new myelographic contrast agent, was used as a reference substance throughout the study. Supracortical subarachnoidal administration of metrizamide caused, within a few minutes, symptoms of sedation and anxiety, which were accompanied by appearance of slow wave or flattening in EEG not only of the cortex, but also of the regions of the hippocampus and thalamus. The rates of local cerebral glucose utilization (LCGU) in a wide range of the brain, measured by using 3H-2-deoxyglucose, were also altered significantly. Despite a limited distribution of metrizamide in the lateral region of the cortex, LCGU was suppressed significantly in the administered side of the parietal cortex, thalamus, subthalamic nucleus, medial geniculate body, and mammillary body and increased in the regions of hippocampus, caudate-putamen, and globus pallidus. It is concluded that, rather than inhibiting the hexokinase reaction in the brain cell, metrizamide appears to cause reduction of a net glucose transport into the cell and that this direct effect on the cortex is amplified and propagated, via neurotransmission, to the regions of the diencephalon and midbrain, causing secondarily various types of disturbance in the mental and motor functions. Iotrolan was proved to lack any biologic activity that may relate to the neural adverse effect observed with metrizamide.
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PMID:A possible mechanism for the neural adverse reactions caused by metrizamide. 256 81

A case of Iotrolan encephalopathy is reported. A 66-year-old woman, suffering from subarachnoid hemorrhage, was admitted to our department on January 17th, 1995. After an operation for aneurysmal clipping and ventriculo-peritoneal shunt, she was discharged with no neurological deficiency. CT scan revealed ventricular enlargement and slight periventricular lucency. She was re-admitted on January 4th, 1996. She was suffering from nausea, vomiting, right hemiparesis, right hemi-hypesthesia and disturbance of consciousness. CT scan demonstrated right thalamic bleeding and bilateral ventricular hemorrhage. Further ventricular enlargement was also revealed. With medical treatment, her symptoms were relieved gradually. But disorientation and memory disturbance continued. Shuntography with Iotrolan was performed on February 2nd, 1996. The ventriculo-peritoneal shunt was demonstrated to be occluded on the abdominal side. The volume of Iotrolan used was about 8cc. She became very restless on the night of the examination. Her temperature was up to 38. CT on February 4th demonstrated brain penetration of the Iotrolan. Revision of ventriculo-peritoneal shunt, administration of steroids and hydration was performed. CSF findings demonstrated no abnormalities. Her symptoms were relieved gradually. Iotrolan is a non-ionic contrast media of dimer type, composed of C37 H48 I6 N6 O18. Its distinctive features are low distributing coefficient and high affinity with water. Contrasting several reports of Metrizamide encephalopathy, only 2 cases of Iotrolan encephalopathy were reported. Iotrolan is reported to be much safer than Metrizamide. We were able to find brain penetration by Iotrolan. It is expected to be a characteristic radiological finding of encephalopathy induced by contrast media. The mechanism of Iotrolan encephalopathy is obscure. Several theories concerning Metrizamide encephalopathy are proposed. These are (1) inhibition of hexokinase, (2) inhibition of acethylcholinesterase, (3) immunological mechanism and (4) vascular disturbance. Iotrolan has no 2-deoxy-glucose structure. The inhibition theory of hexokinase is least expected. Related matters are circulatory disturbance of liquor, dehydration, excessive contrast media, advanced age, diabetes mellitus, hypertension, epileptic patients and patients taking phenothiazines. Prompt therapy is important. Removal of contrast media, hydration and administration of steroids should be performed as early as possible.
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PMID:[A case of Iotrolan encephalopathy]. 893 76