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Objective validation of central sensitization in the rat UVB and heat rekindling model.

Weerasinghe NS, Lumb BM, Apps R, Koutsikou S, Murrell JC - Eur J Pain (2014)

Bottom Line: MWT was compared between UVB/HR and SHAM-treated rats (anaesthetic only).Secondary hyperalgesia was confirmed by a significantly lower pre-drug MWT {mean [±standard error of the mean (SEM)]} in UVB/HR [56.3 (±2.1) g/mm(2) , n = 15] compared with SHAM-treated rats [69.3 (±2.9) g/mm(2) , n = 8], confirming face validity of the model.Predictive validity was demonstrated by the attenuation of secondary hyperalgesia by MK-801, where mean (±SEM) MWT was significantly higher [77.2 (±5.9) g/mm(2) n = 7] in comparison with pre-drug [57.8 (±3.5) g/mm(2) n = 7] and saline [57.0 (±3.2) g/mm(2) n = 8] at peak drug effect.

View Article: PubMed Central - PubMed

Affiliation: School of Physiology and Pharmacology, University of Bristol, UK.

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Related in: MedlinePlus

Figures showing the effect of intrathecal administration of N-methyl-d-aspartate receptor antagonist, MK-801 or saline on mechanical withdrawal threshold (MWT) in response to a pinch of increasing magnitude in the mid-region (i.e., area of secondary hyperalgesia) of the ipsilateral hind paw. An example of raw data from a UVB/HR rat is demonstrated in (Ai) showing a pre-drug MWT response and (Aii) MWT 30 min after MK-801 administration in the same rat. Scale bars correlate to both (Ai) and (Aii). (B) Time course of drug action in all groups [UVB/HR + MK-801 = 7 (squares), UVB/HR + saline =8 (circles), SHAM + MK-801 = 8 (triangles)] where MK-801 or saline was administered immediately after obtaining pre-drug responses. Post-drug responses were recorded every 15 min for 60 min, where each data point represents mean ± standard error of the mean 4 days after initial UVB or SHAM treatment. **p < 0.01 within group, ##p < 0.01 between groups, two-way analysis of variance following by Bonferroni post hoc test.
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fig02: Figures showing the effect of intrathecal administration of N-methyl-d-aspartate receptor antagonist, MK-801 or saline on mechanical withdrawal threshold (MWT) in response to a pinch of increasing magnitude in the mid-region (i.e., area of secondary hyperalgesia) of the ipsilateral hind paw. An example of raw data from a UVB/HR rat is demonstrated in (Ai) showing a pre-drug MWT response and (Aii) MWT 30 min after MK-801 administration in the same rat. Scale bars correlate to both (Ai) and (Aii). (B) Time course of drug action in all groups [UVB/HR + MK-801 = 7 (squares), UVB/HR + saline =8 (circles), SHAM + MK-801 = 8 (triangles)] where MK-801 or saline was administered immediately after obtaining pre-drug responses. Post-drug responses were recorded every 15 min for 60 min, where each data point represents mean ± standard error of the mean 4 days after initial UVB or SHAM treatment. **p < 0.01 within group, ##p < 0.01 between groups, two-way analysis of variance following by Bonferroni post hoc test.

Mentions: Centrally acting MK-801 increased MWT in UVB/HR rats in the area of secondary hyperalgesia, with a peak effect observed at 30 min post administration (Fig. 2A).


Objective validation of central sensitization in the rat UVB and heat rekindling model.

Weerasinghe NS, Lumb BM, Apps R, Koutsikou S, Murrell JC - Eur J Pain (2014)

Figures showing the effect of intrathecal administration of N-methyl-d-aspartate receptor antagonist, MK-801 or saline on mechanical withdrawal threshold (MWT) in response to a pinch of increasing magnitude in the mid-region (i.e., area of secondary hyperalgesia) of the ipsilateral hind paw. An example of raw data from a UVB/HR rat is demonstrated in (Ai) showing a pre-drug MWT response and (Aii) MWT 30 min after MK-801 administration in the same rat. Scale bars correlate to both (Ai) and (Aii). (B) Time course of drug action in all groups [UVB/HR + MK-801 = 7 (squares), UVB/HR + saline =8 (circles), SHAM + MK-801 = 8 (triangles)] where MK-801 or saline was administered immediately after obtaining pre-drug responses. Post-drug responses were recorded every 15 min for 60 min, where each data point represents mean ± standard error of the mean 4 days after initial UVB or SHAM treatment. **p < 0.01 within group, ##p < 0.01 between groups, two-way analysis of variance following by Bonferroni post hoc test.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4232048&req=5

fig02: Figures showing the effect of intrathecal administration of N-methyl-d-aspartate receptor antagonist, MK-801 or saline on mechanical withdrawal threshold (MWT) in response to a pinch of increasing magnitude in the mid-region (i.e., area of secondary hyperalgesia) of the ipsilateral hind paw. An example of raw data from a UVB/HR rat is demonstrated in (Ai) showing a pre-drug MWT response and (Aii) MWT 30 min after MK-801 administration in the same rat. Scale bars correlate to both (Ai) and (Aii). (B) Time course of drug action in all groups [UVB/HR + MK-801 = 7 (squares), UVB/HR + saline =8 (circles), SHAM + MK-801 = 8 (triangles)] where MK-801 or saline was administered immediately after obtaining pre-drug responses. Post-drug responses were recorded every 15 min for 60 min, where each data point represents mean ± standard error of the mean 4 days after initial UVB or SHAM treatment. **p < 0.01 within group, ##p < 0.01 between groups, two-way analysis of variance following by Bonferroni post hoc test.
Mentions: Centrally acting MK-801 increased MWT in UVB/HR rats in the area of secondary hyperalgesia, with a peak effect observed at 30 min post administration (Fig. 2A).

Bottom Line: MWT was compared between UVB/HR and SHAM-treated rats (anaesthetic only).Secondary hyperalgesia was confirmed by a significantly lower pre-drug MWT {mean [±standard error of the mean (SEM)]} in UVB/HR [56.3 (±2.1) g/mm(2) , n = 15] compared with SHAM-treated rats [69.3 (±2.9) g/mm(2) , n = 8], confirming face validity of the model.Predictive validity was demonstrated by the attenuation of secondary hyperalgesia by MK-801, where mean (±SEM) MWT was significantly higher [77.2 (±5.9) g/mm(2) n = 7] in comparison with pre-drug [57.8 (±3.5) g/mm(2) n = 7] and saline [57.0 (±3.2) g/mm(2) n = 8] at peak drug effect.

View Article: PubMed Central - PubMed

Affiliation: School of Physiology and Pharmacology, University of Bristol, UK.

Show MeSH
Related in: MedlinePlus