Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0344307 (analgesia)
 28,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The possibility that the GABAA receptor is involved in supraspinal morphine analgesia was investigated in rats using pentobarbital and other GABAA receptor-chloride channel ligands. Inhibition of tail-flick was used as an index of analgesia. Pentobarbital almost completely reversed intracerebroventricular (i.c.v.) morphine analgesia, but did not affect intrathecal (i.t.) morphine analgesia. Phenobarbital had a similar effect but was much weaker. Picrotoxin blocked the reversal effect of pentobarbital. Diazepam, when given together with pentobarbital, enhanced the effect of pentobarbital. Furthermore, muscimol reversed i.c.v. morphine analgesia without affecting i.t. morphine analgesia. Our results strongly suggest that the GABAA receptor is involved in supraspinal morphine analgesia.
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PMID:Pentobarbital selectively blocks supraspinal morphine analgesia. Evidence for GABAA receptor involvement. 196 87

The comparative metabolism of the natural (-)- and the unnatural (+)-morphine was studied in liver microsomes from phenobarbital-treated, morphine-treated and control rats. (-)-Morphine was glucuronidated only at position 3 with the formation of (-)-morphine-3-glucuronide [(-)-M3G] at an average rate of 2.19 nmol X mg protein-1 X min-1. In contrast, (+)-morphine was conjugated preferentially at position 6. The rate of formation of (+)-morphine-6-glucuronide [(+)-M6G] was 3.1 times higher than that of (+)-M3G (0.92 and 0.30 nmol X mg protein-1 X min-1, respectively). Natural morphine was N-demethylated at an average rate of 0.42 nmol X mg protein-1 X min-1, and this rate of N-demethylation was about twice as high as that of (+)-morphine (0.17 nmol X mg protein-1 X min-1). Phenobarbital treatment led to a 3- to 4-fold increase in the formation rate of (-)-M3G and (+)-M6G whereas the glucuronidation of (+)-morphine at position 3 was increased only marginally. No change in the N-demethylation of either enantiomer was observed. In contrast, pretreatment with (-)-morphine decreased the N-demethylation of both enantiomers by about 80% without any effect on the glucuronidation. The increased ratio of the rate of (+)-M6G/(+)-M3G formation after phenobarbital treatment indicates that different isozymes may be involved in the two reactions. This study demonstrates that there is an inherent substrate stereoselectivity and site selectivity for morphine in the rat hepatic uridine 5'-diphosphate-glucuronyltransferase although not as critical as for the opiate receptors mediating analgesia.
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PMID:Natural (-)- and unnatural (+)-enantiomers of morphine: comparative metabolism and effect of morphine and phenobarbital treatment. 392 76

The course of ischemic increase of extracellular potassium concentration ([K+]e) was studied in rat cerebral cortex with potassium selective microelectrodes and correlated to the preischemic functional and metabolic state. Complete cerebral ischemia was induced in artificially ventilated rats by cardiac arrest. Seven different functional states including conditions with cerebral hypermetabolism (seizures, amphetamine intoxication, hyperthermia) and hypometabolism (barbiturate anesthesia, hypothermia) were chosen in order to cover a wide range of cerebral metabolic rates (CMRO2 : 28.7--2.4 ml O2/(100 g)/min). The ischemic increase of [K+]e was delayed in conditions with low CMRO2 and accelerated in conditions with high CMRO2; the time interval to the terminal steep rise in extracellular potassium concentration varied within the extremes of 35 +/- 5 and 365 +/- 12 sec (means +/- S.E.M.), the control state (N2O-analgesia) being 116 +/- 5 sec. In groups with high CMRO2 electrocortical activity ceased within 15 sec and in groups with low CMRO2 within 22 sec. The rates of the ischemic [K+]e increase, measured as rate of change in the potassium electrode potential (mV/sec), remained high in conditions with high preischemic CMRO2 and low in conditions with low CMRO2, indicating a remaining influence of the preischemic metabolism on membrane ion permeability. These results support previous metabolic data indicating that the rate of consumption of high energy phosphates during ischemia mirrors the preischemic cerebral metabolic rate. Phenobarbital anesthesia did not change the initial rate of [K+]e increase but reduced the rate of [K+]e increase later during ischemia, suggesting a special effect of barbiturates on partly depolarized membranes.
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PMID:The increase in extracellular potassium concentration in the ischemic brain in relation to the preischemic functional activity and cerebral metabolic rate. 740 19

Acute appendicitis is the most common reason for abdominal surgery in children. Luminal obstruction of the appendix progresses to suppurative inflammation and perforation, which causes generalised peritonitis or an appendix mass/abscess. Classical features include periumbilical pain that migrates to the right iliac fossa, anorexia, fever, and tenderness and guarding in the right iliac fossa. Atypical presentations are particularly common in preschool children. A clinical diagnosis is possible in most cases, after a period of active observation if necessary; inflammatory markers and an ultrasound scan are useful investigations when the diagnosis is uncertain. Treatment is by appendicectomy after appropriate fluid resuscitation, analgesia and intravenous antibiotics. Laparoscopic appendicectomy is better than open appendicectomy in most cases because it is associated with less postoperative pain and a shorter hospital stay, but recovery after acute appendicitis is mostly dictated by whether the appendix was perforated or not. Management of the appendix mass remains controversial and not all affected children need an interval appendicectomy. This article discusses tips and pitfalls in diagnosis and addresses many of the controversies that surround the management of this condition.
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PMID:Acute appendicitis. 2904 90