In: Anesthesia5 Oct 2009
Exposure to 60% N20 over a period of 24 hours did not affect viability of the GT1-7 cells. The total protein content of the cells was also not significantly different between air-exposed and N20-exposed cells. The effects of oxygen concentration (21% vs 35%) on cell viability and protein concentration over 36 hours were also evaluated in a series of preliminary studies. Thirty-five percent oxygen concentration did not have any significant effects on these measures.
Effect of N20 on GnRH mRNA Levels
Exposure to 60% N20 over a period of 24 hours resulted in a significant decrease in GnRH mRNA levels as seen on Northern blots (Figure 1A) and after normalizing the RNA concentration with respect to the housekeeping gene G3PDH (Figure 1B).
Figure 1. Northern blots (replicate of 2 experiments) showing significant decrease in signal intensity of GnRH mRNA levels (A) in cells exposed to 60% N20 compared to air-exposed control cells. Quantitative changes in GnRH mRNA levels after exposure to N20 or air, replicate of 2 experiments (B). Note that 24 hrs exposure to N20 results in a significant (P<0.05) decrease (approximately 80%) in GnRH mRNA levels compared to air exposed controls. RNA concentration was normalized with respect to housekeeping gene G3PDH.
Effect of NzO on p44/42 Phosphorylation
Exposure to 60% N20 for various time periods (0-60 minutes) has no effect on p44/42 phosphorylation in GT1-7 cells (Figure 2).
Figure 2. Effect of N20 exposure on p44/42 phosphorylation. Results indicate exposure to N20 does not induce p44/42 phosphorylation.
Effect of N20 on p38 Phosphorylation
Exposure to 60% N20 for 10-180 minutes did not induce p38 phosphorylation (Figure 3). Exposure to N20 results in a significant (P<0.05) decrease (approximately 80%) in GnRH mRNA levels compared to air exposed controls. RNA concentration was normalized with respect to housekeeping gene G3PDH.
Figure 3. Effect of N20 exposure on p38 phosphorylation. Nitrous oxide exposure did not influence p38 phosphorylation.
Effect of N20 on p63 Phosphorylation
Significant increases in p63 tyrosine phosphorylation occurred after exposure to 60% N20 at 90-120 minutes (Figure 4). generic viagra uk
Figure 4. Effect of N20 exposure on p63 phosphorylation. Significant increase in p63 protein phosphorylation was observed at 90 and 120 minutes of exposure to N2Q.
Effect of N20 on C-fos
Exposure to 60% N20 for either 3 or 12 hours did not alter the levels of transcription factor c-fos (Figure 5).
Figure 5. Effect of N20 exposure on transcription factor c-fos. Nitrous oxide exposure did not affect c-fos.
Effect of 60% N20 on IKB
Exposure to 60% N20 for 10-180 minutes did not significantly alter IKB degradation in GT1-7 cells (Figure 6). buy aricept
Figure 6. Effect of N20 exposure on IkB. Exposure to N20 did not influence IkB phosphorylation.
Effect of 60% N20 on KCl-Induced GnRH Release From GT1-7 Cells
Nitrous oxide did not appear to significantly alter intracellular levels of GnRH over 24-hour exposure , but exposure to 60% N20 significantly decreased the ability of KC1 to release GnRH into the medium.
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