Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0085383 (hypocapnia)
 1,697 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The purpose of this study is to investigate the mechanisms of the effect of hyperventilation on the spinal pain modulating system by using phentolamine. Under enflurane anaesthesia, cats received mid-collicular decerebration and lumbar laminectomy. The spinal cord was transected at T12-L1. WDR cells, responding primarily to noxious peripheral stimuli, were sampled with a microelectrode at the depth of 2,000 microns from the cord dorsum. Following the control period, ventilation was changed to induce hypocapnia of PCO2 20-25 mmHg. After activities were well suppressed, phentolamine 0.5 mg with normal saline 1.0 ml was injected on the spinal cord. Changes of firings were investigated. When normocapnia was resumed, recovery followed. Hypocapnia of PCO2 20-25 mmHg significantly suppressed the activities of WDR cells. Phentolamine significantly antagonized the suppressive effects of hyperventilation upon the activities of WDR cells. Our results suggest that the hyperventilation has suppressive effects on single-unit activity of WDR cell and the mechanisms of those suppressive effects are related to adrenergic pain modulating system.
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PMID:[Effects of hyperventilation upon the spinal pain modulating system (third report)]. 781 94

The purpose of this study is to investigate the effect of hyperventilation on the spinal pain modulating system by using naloxone. Under enflurane anaesthesia, cats were prepared with midcollicular decerebration and lumbar laminectomy. The spinal cord was transected at T12-L1. WDR cells, responding primarily to noxious peripheral stimuli, were sampled with a microelectrode at the depth of 2,000 microns from the cord dorsum. Following the control period, ventilation was adjusted to produce hypocapnia of PCO2 20-25 mmHg. After activities of WDR cells were well suppressed, naloxone 0.1 mg.kg-1 was given intravenously. Changes of firings of WDR cells were investigated. Returning to normocapnia, recovery of firings was followed. Hypocapnia of PCO2 20-25 mmHg significantly suppressed the activities of WDR cells. Naloxone significantly antagonized the suppressive effects of hyperventilation upon the activity of WDR cell. Our results suggest that the hyperventilation has suppressive effects on single-unit activity of WDR cell and the mechanisms of those suppressive effects are related to pain modulating system by endogenous opiates.
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PMID:[The effects of hyperventilation upon the spinal pain modulating system (second report)]. 818 71

The purpose of this study is to investigate the effects of hyperventilation on the wide dynamic range (WDR) cell of the dorsal horn of the feline lumbar spinal cord. Cats received midcollicular decerebration and lumbar laminectomy. The spinal cord was transected at T12-L1. WDR cells were sampled with microelectrode at the depth of 2,000 microns from the cord dorsum. Following the control period with PaCO2 of 35-45 mmHg, respiratory rate and tidal volume were adjusted to make a level of hypocapnia as low as 20-25 mmHg. The recovery of cell activity was followed when normocapnia was restored. Hypocapnia with PaCO2 of 25-30 mmHg and 20-25 mmHg suppressed the activity of WDR cell significantly. At PaCO2 of 25-30 mmHg, the spontaneous activity was suppressed for about 20% and evoked activity for 27%. At PaCO2 of 20-25 mmHg, the spontaneous activity was suppressed for about 50% and evoked activity for 33%. The results suggest that the hyperventilation has suppressive effects on single-unit activity of WDR cell.
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PMID:[The effects of hyperventilation upon the spinal pain modulating system]. 830 24