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Immediate and Long-Term Outcome of Acute H2S Intoxication Induced Coma in Unanesthetized Rats: Effects of Methylene Blue.

Sonobe T, Chenuel B, Cooper TK, Haouzi P - PLoS ONE (2015)

Bottom Line: The aim of our study was to 1--describe the immediate and long-term neurological effects following H2S-induced coma in un-anesthetized rats, and 2--determine the potential benefit of methylene blue (MB), a compound we previously found to counteract acute sulfide cardiac toxicity.The treated animals displayed a significantly higher occurrence of spatial search than the non-treated animals.However, a similar proportion of cortical necrosis was observed in both groups, with a milder clinical presentation following MB.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Division of Pulmonary and Critical Care Medicine, Pennsylvania State University, College of Medicine, Hershey, PA, United States of America.

ABSTRACT

Background: Acute hydrogen sulfide (H2S) poisoning produces a coma, the outcome of which ranges from full recovery to severe neurological deficits. The aim of our study was to 1--describe the immediate and long-term neurological effects following H2S-induced coma in un-anesthetized rats, and 2--determine the potential benefit of methylene blue (MB), a compound we previously found to counteract acute sulfide cardiac toxicity.

Methods: NaHS was administered IP in un-sedated rats to produce a coma (n = 34). One minute into coma, the rats received MB (4 mg/kg i.v.) or saline. The surviving rats were followed clinically and assigned to Morris water maze (MWM) and open field testing then sacrificed at day 7.

Results: Sixty percent of the non-treated comatose rats died by pulseless electrical activity. Nine percent recovered with neurological deficits requiring euthanasia, their brain examination revealed major neuronal necrosis of the superficial and middle layers of the cerebral cortex and the posterior thalamus, with variable necrosis of the caudate putamen, but no lesions of the hippocampus or the cerebellum, in contrast to the typical distribution of post-ischemic lesions. The remaining animals displayed, on average, a significantly less effective search strategy than the control rats (n = 21) during MWM testing. Meanwhile, 75% of rats that received MB survived and could perform the MWM test (P<0.05 vs non-treated animals). The treated animals displayed a significantly higher occurrence of spatial search than the non-treated animals. However, a similar proportion of cortical necrosis was observed in both groups, with a milder clinical presentation following MB.

Conclusion: In conclusion, in rats surviving H2S induced coma, spatial search patterns were used less frequently than in control animals. A small percentage of rats presented necrotic neuronal lesions, which distribution differed from post-ischemic lesions. MB dramatically improved the immediate survival and spatial search strategy in the surviving rats.

No MeSH data available.


Related in: MedlinePlus

Histology of the frontal cerebral cortex in one rat of the H2S-MB group (#98, see Table 1) that could swim and find the platform.Marked asymmetry of neuronal necrosis in the left hemisphere was found, while the right hemisphere was nearly normal (Bregma 0.0. 40x). All other lesions in this rat (Table 1) were ipsilateral.
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pone.0131340.g013: Histology of the frontal cerebral cortex in one rat of the H2S-MB group (#98, see Table 1) that could swim and find the platform.Marked asymmetry of neuronal necrosis in the left hemisphere was found, while the right hemisphere was nearly normal (Bregma 0.0. 40x). All other lesions in this rat (Table 1) were ipsilateral.

Mentions: In H2S-MB groups, the 2 rats that were unable to find the platform presented the same types of lesions as the 2 rats that had to be euthanized in the H2S group. To our surprise, one of the 7 rats able to find the platform had significant brain lesions (Fig 13), while the brains of the other 6 animals were normal. This rat displayed notably asymmetrical neuronal necrosis of the superficial and middle laminae of the cerebral cortex (the frontal, occipital, parietal and temporal lobes) and the cingulate gyrus. The piriform cortex, corpus callosum, caudate putamen and hippocampus were unaffected.


Immediate and Long-Term Outcome of Acute H2S Intoxication Induced Coma in Unanesthetized Rats: Effects of Methylene Blue.

Sonobe T, Chenuel B, Cooper TK, Haouzi P - PLoS ONE (2015)

Histology of the frontal cerebral cortex in one rat of the H2S-MB group (#98, see Table 1) that could swim and find the platform.Marked asymmetry of neuronal necrosis in the left hemisphere was found, while the right hemisphere was nearly normal (Bregma 0.0. 40x). All other lesions in this rat (Table 1) were ipsilateral.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4482667&req=5

pone.0131340.g013: Histology of the frontal cerebral cortex in one rat of the H2S-MB group (#98, see Table 1) that could swim and find the platform.Marked asymmetry of neuronal necrosis in the left hemisphere was found, while the right hemisphere was nearly normal (Bregma 0.0. 40x). All other lesions in this rat (Table 1) were ipsilateral.
Mentions: In H2S-MB groups, the 2 rats that were unable to find the platform presented the same types of lesions as the 2 rats that had to be euthanized in the H2S group. To our surprise, one of the 7 rats able to find the platform had significant brain lesions (Fig 13), while the brains of the other 6 animals were normal. This rat displayed notably asymmetrical neuronal necrosis of the superficial and middle laminae of the cerebral cortex (the frontal, occipital, parietal and temporal lobes) and the cingulate gyrus. The piriform cortex, corpus callosum, caudate putamen and hippocampus were unaffected.

Bottom Line: The aim of our study was to 1--describe the immediate and long-term neurological effects following H2S-induced coma in un-anesthetized rats, and 2--determine the potential benefit of methylene blue (MB), a compound we previously found to counteract acute sulfide cardiac toxicity.The treated animals displayed a significantly higher occurrence of spatial search than the non-treated animals.However, a similar proportion of cortical necrosis was observed in both groups, with a milder clinical presentation following MB.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Division of Pulmonary and Critical Care Medicine, Pennsylvania State University, College of Medicine, Hershey, PA, United States of America.

ABSTRACT

Background: Acute hydrogen sulfide (H2S) poisoning produces a coma, the outcome of which ranges from full recovery to severe neurological deficits. The aim of our study was to 1--describe the immediate and long-term neurological effects following H2S-induced coma in un-anesthetized rats, and 2--determine the potential benefit of methylene blue (MB), a compound we previously found to counteract acute sulfide cardiac toxicity.

Methods: NaHS was administered IP in un-sedated rats to produce a coma (n = 34). One minute into coma, the rats received MB (4 mg/kg i.v.) or saline. The surviving rats were followed clinically and assigned to Morris water maze (MWM) and open field testing then sacrificed at day 7.

Results: Sixty percent of the non-treated comatose rats died by pulseless electrical activity. Nine percent recovered with neurological deficits requiring euthanasia, their brain examination revealed major neuronal necrosis of the superficial and middle layers of the cerebral cortex and the posterior thalamus, with variable necrosis of the caudate putamen, but no lesions of the hippocampus or the cerebellum, in contrast to the typical distribution of post-ischemic lesions. The remaining animals displayed, on average, a significantly less effective search strategy than the control rats (n = 21) during MWM testing. Meanwhile, 75% of rats that received MB survived and could perform the MWM test (P<0.05 vs non-treated animals). The treated animals displayed a significantly higher occurrence of spatial search than the non-treated animals. However, a similar proportion of cortical necrosis was observed in both groups, with a milder clinical presentation following MB.

Conclusion: In conclusion, in rats surviving H2S induced coma, spatial search patterns were used less frequently than in control animals. A small percentage of rats presented necrotic neuronal lesions, which distribution differed from post-ischemic lesions. MB dramatically improved the immediate survival and spatial search strategy in the surviving rats.

No MeSH data available.


Related in: MedlinePlus