| Evidence Sentence: |
Expression levels of the hypothalamic AMPK gene determines the responsiveness of the rats to electroacupuncture-induced analgesia |
| Evidence Sentence: |
Our functional genomic study using cDNA microarray identified that 5'-AMP-activated protein kinase (AMPK), a well-known factor in the regulation of energy homeostasis, is the most highly expressed gene in the hypothalamus of the rats that were sensitive to EA analgesia (responder), as compared to the rats that were insensitive to EA analgesia (non-responder). |
| Evidence Sentence: |
In this study, we investigated the causal relationship between the hypothalamic AMPK and the individual variation in EA analgesia. |
| Evidence Sentence: |
Real-time reverse transcription-polymerase chain reaction (RT-PCR) was performed to quantify the expression levels of AMPK mRNA in the hypothalamus of the responder and non-responder rats. |
| Evidence Sentence: |
Further, we examined whether viral manipulation of the AMPK expression in the hypothalamus modulates EA analgesia in rats. |
| Evidence Sentence: |
The real-time RT-PCR analysis showed that mRNA expression levels of AMPK in the hypothalamus of the responder rats are significantly higher than those of the non-responder rats, validating the previous microarray results. |
| Evidence Sentence: |
Microinjection of dominant negative (DN) AMPK adenovirus, which inhibits AMPK activity, into the rat hypothalamus significantly attenuates EA analgesia (p < 0.05), whereas wild type (WT) AMPK virus did not affect EA analgesia (p > 0.05). |
| Evidence Sentence: |
The present results demonstrated that levels of AMPK gene expression in the rat hypothalamus determine the individual differences in the sensitivity to EA analgesia. |
| Evidence Sentence: |
Measurement of AMPK mRNA levels in the rat hypothalamus by real-time RT-PCR |
| Evidence Sentence: |
Expression level of AMPK mRNA was normalized by that of a house keeping gene, GAPDH (Glyceraldehyde-3-phosphate dehydrogenase). |
| Evidence Sentence: |
As shown in Figure 2, the normalized mRNA levels of AMPK in the responder rats are significantly higher than those of non-responder rats (p < 0.01). |
| Evidence Sentence: |
Effects of adenoviral gene transfer of AMPK into the hypothalamus on EA-induced analgesia |
| Evidence Sentence: |
In order to determine whether adenoviral gene transfer of AMPK into the rat hypothalamus by itself affects the sensitivity to thermal stimuli, we compared the baseline TFL between the AMPK WT virus-injected and DN virus-injected rats that measured before EA stimulation on days -1, 3, 7 and 14 following viral injection. |
| Evidence Sentence: |
To see whether WT AMPK virus and DN AMPK virus gene expression in the hypothalamus alter EA-induced analgesic effects, we compared the TFL increase ratio between the WT AMPK virus-injected and DN AMPK virus-injected rats. |
| Evidence Sentence: |
In consistent with the role of DN AMPK virus transfection in inhibiting AMPK activity, EA-induced analgesic effects were markedly decreased in a time dependent manner after microinjection of DN AMPK virus into the hypothalamus (Figure 4). |
| Evidence Sentence: |
DN AMPK virus-injected rats showed a significant decrease in TFL increase ratio after EA at 14 days post-injection as compared to the value at pre-injection day (p < 0.05). |
| Evidence Sentence: |
Conversely, WT AMPK virus-injected rats showed no significant difference in TFL increase ratio between the pre-injection day and the post-injection days (p > 0.05). |
| Evidence Sentence: |
Comparison of the TFL increase ratio shows a significant difference between the WT and DN AMPK virus-injected rats on the 7th (p < 0.05) and 14th (p < 0.001) days following the injection (Figure 4). |
