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)

In order to observe the effects of morphine on protein metabolism in mouse brain, experimental procedures were carried out over a 7 hr period of infusion. When the analgesia reached a peak, namely around 2 hr after the start of infusion, the in vivo incorporation of radioactive leucine into protein estimated by the dual label technique was uniformally depressed in all the examined subcellular fractions of both brain and liver. After tolerance developed, however, the incorporation of leucine increased to a much higher level than the control in brain subcellular fractions and the increase was masked by naloxone. In contrast, the incorporation into a TCA soluble fraction of the brain S2, separated by Gray and Whittaker's method, was more than doubled even after 4 hr infusion. While the in vitro incorporation rate of the mitochondrial fraction significantly fluctuated during development of tolerance with naloxone that of the synaptosomal fraction did not fluctuate. The observed coincidence in the time course of development of tolerance and changes in the brain protein synthesis indicates a possible relationship between the phenomena, though the causal nature of the relationship could not be elucidated.
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PMID:Protein synthesis in mouse brain during development of acute morphine tolerance. 120 9

Comparative studies were made on morphine- and stress-induced analgesia (SIA) and also on the development of tolerance to the effects. Cycloheximide (CYH), a potent protein synthesis inhibitor, did not affect the analgesic effect of morphine, but effectively suppressed the development of tolerance. CYH, however, potentiated both foot shock (FS) and immobilized-water immersion (IW) SIAs and inhibited the development of tolerance to FS-SIA. Incorporation of 3H-leucine into the TCA-insoluble fraction of mouse brain regions was inhibited by morphine, and the inhibition was reversed by the pretreatment with CYH. The inhibitory effect of morphine was lost in morphine tolerant animals. At the peak of SIA, incorporation of 3H-leucine was not changed in FS-SIA, but significantly inhibited in IW-SIA, and these effects were not modified by the pretreatment with CYH. The reduced incorporation of 3H-leucine in IW-SIA tolerant animals was partially reversed by CYH. Thus, the protein synthesis mechanism is greatly influenced by morphine or stresses, but the direct evidence for the implication of the mechanism in the process of producing analgesia and tolerance formation could not be demonstrated. However, differences in the underlying mechanisms were apparent between morphine and SIAs and also between FS- and IW-SIA.
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PMID:Comparative studies on morphine- and stress-induced analgesia and the development of tolerance to the effects: implication of protein synthesis mechanism in the process. 399 72