Journal of basic and clinical physiology and pharmacology
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J Basic Clin Physiol Pharmacol · Jan 1995
Effect of accumulation of CO2 on the survival of immature pigs in a confined atmosphere. B: Blood gas exchange.
As part of a study for developing survival strategy for humans in a confined space, we used immature pigs to assess the applicability of findings in rats and to evaluate the effect of body size. The cannulated unanesthetized animal was placed in a sealed chamber and depleted the oxygen until hypoxic collapse. Three groups were: no accumulation of CO2, CO2 maintained at 5%, and maximal accumulation of CO2. ⋯ Oxygen extraction increased and oxygen transport decreased in hypoxia in the presence of CO2. Similarity in the P50 of the oxygen dissociation curve may explain the similar terminal PIO2 in the pig and the rat. There was a positive correlation between terminal PIO2 and terminal venous pH.
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J Basic Clin Physiol Pharmacol · Jan 1991
ReviewChronic pain in the aged: possible relation between neurogenesis, involution and pathophysiology in adult sensory ganglia.
Certain neuropathic pain states, including postherpetic neuralgia and trigeminal neuralgia, show a dramatically increased incidence in the aged. Two recent experimental observations, unrelated a priori, might provide insight into why this is so. The first observation appeared unexpectedly during the course of a quantitative morphometric study aimed at determining the kinetics of retrograde cell death in dorsal root ganglia (DRGs) of adult male rats after nerve injury. ⋯ It is likely that these post-injury changes in DRG electrogenesis contribute to the neuropathic sensory abnormalities, including chronic pain, that are associated with traumatic nerve injury. Considering both observations together, it is possible that DRG involution in the aged triggers electrical changes in the DRG resembling those associated with DRG involution following nerve injury. If so, this process could account for the special susceptibility of elderly patients to certain neuropathic pain states.