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)

Rats exposed to inescapable foot shock displayed an increase in respiratory rate, tidal volume and minute volume. Naloxone HCl (5 mg/kg, SC) potentiated the foot shock-induced increase in ventilation. Inhalation of high (5% and 10%) concentrations of carbon dioxide enhanced the stimulation of ventilation observed in both the acute stressed animals and the acute stress-naloxone treated group. Chronic daily foot shock sessions (11 days) attenuated the respiratory stimulation produced by acute foot shock and the potentiation induced by naloxone. The appearance of foot shock-induced stimulation of respiration paralleled the production of acute foot shock-induced analgesia. On the other hand, chronic foot shock attenuated both stress-related analgesia and respiratory stimulation. These results strongly suggest stress can influence respiratory function through activation or release of the endogenous opioids. It is postulated that the endorphinergic system functions as a compensatory system which prevents excessive stimulation of respiration by stress.
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PMID:Interaction of acute and chronic stress with respiration: modification by naloxone. 680 52

Mice selectively bred for high (HA) and for low analgesia (LA) induced by 3-min swimming at 20 degrees C and unselected controls (C) were injected three times daily for 3 days with 20 mg/kg morphine HCl. The analgesic effect of 10 mg/kg morphine in nontolerant mice differed between the lines in the rank order of HA > C > LA and significantly decreased after repeated treatment with morphine, as revealed by the hotplate test (56 degrees C). The tolerance to morphine analgesia was more pronounced in HA than in C mice but did not develop at all in LA mice. Similarly, the magnitude of swim-induced analgesia in morphine tolerant mice decreased to a greater degree in the HA than the C line but did not change in LA mice. Naloxone HCl (1 and 10 mg/kg) attenuated swim analgesia more in nontolerant HA than C mice but had no effect in morphine-tolerant HA and C and in all LA mice. The differential degree of morphine tolerance and cross-tolerance with swim analgesia suggests that the strategy of selective breeding toward divergent magnitudes of stress-induced analgesia has differentiated opioid involvement in endogenous pain inhibition in the selected lines.
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PMID:Cross-tolerance between morphine and swim analgesia in mice selectively bred for high and low stress-induced analgesia. 833 12