In vitro - Mouse vas deferens bath - slow to recover after wash

[chrisr]

Hello,

I'm intending to test some opioids on MVD tissue and am having a problem with tissue recovery after washing. I've ensured that the new Kreb's flowing into the system is both warmed to the correct temperature (31 degC) and sufficiently oxygenated by carbogen flow.

I initially thought that the agonist I was adding was just not washing out and thus the tissue response to the applied field stimulus was not recovering. However, I've now run a control experiment in which the agonist was not added over a period similar to that taken to construct the dose-response curve, and found that washing with Kreb's again caused a significant reduction in tissue response which then took over an hour to recover. Any ideas??

Thanks,

Chris

[kstarhero]

I have had similar problems before. I never really found the real problem, but i think it may be:

- fatigue of tissue, if you use it too many times
- contaminated Kreb's solution?
- I am presuming you are using a force transducer lever to detect the tension force of the muscle, measured as a percentage of maximal contraction response.
Is it possible that your setup is inadequate e.g. the muscle is not tied correctly, or it may be loose? (alternatively, tied too tightly?)

Good Luck!