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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

Probe trials.Average latency, distance, time spent in the platform quadrant, and number platform crossing are displayed during the probe trial. No significant difference was observed between the 3 groups. Values are shown as mean ± SD.
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pone.0131340.g006: Probe trials.Average latency, distance, time spent in the platform quadrant, and number platform crossing are displayed during the probe trial. No significant difference was observed between the 3 groups. Values are shown as mean ± SD.

Mentions: Daily averaged swimming distance, latency and path efficiency to find the platform are shown on Fig 5. On the 1st day of training, the control group of 21 rats spent an average of 61.8 ± 42.4 sec in the pool to find the platform; they did not find it within 120 sec in 21% of the tests. The total swimming distance was 13.8 ± 9.3 m and path efficiency was 0.14 ± 0.17. The latency decreased very rapidly at D2 and D3 reaching 23.1 ± 25.3 sec (P<0.05) at D4. The total distance also decreased over time averaging 5.0 ± 5.3 m (P<0.05) at D4, while path efficiency reached 0.44 ± 0.33 (P<0.05) as illustrated on Fig 5. Probe test data are shown on Fig 6.


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)

Probe trials.Average latency, distance, time spent in the platform quadrant, and number platform crossing are displayed during the probe trial. No significant difference was observed between the 3 groups. Values are shown as mean ± SD.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0131340.g006: Probe trials.Average latency, distance, time spent in the platform quadrant, and number platform crossing are displayed during the probe trial. No significant difference was observed between the 3 groups. Values are shown as mean ± SD.
Mentions: Daily averaged swimming distance, latency and path efficiency to find the platform are shown on Fig 5. On the 1st day of training, the control group of 21 rats spent an average of 61.8 ± 42.4 sec in the pool to find the platform; they did not find it within 120 sec in 21% of the tests. The total swimming distance was 13.8 ± 9.3 m and path efficiency was 0.14 ± 0.17. The latency decreased very rapidly at D2 and D3 reaching 23.1 ± 25.3 sec (P<0.05) at D4. The total distance also decreased over time averaging 5.0 ± 5.3 m (P<0.05) at D4, while path efficiency reached 0.44 ± 0.33 (P<0.05) as illustrated on Fig 5. Probe test data are shown on Fig 6.

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