The importance of normalizing the preparation is three-fold:
1.
Experiments with elastic preparations like vessels can only have meaning if they are performed under
conditions where the size is clearly defined.
2.
Clearly defined conditions are required in pharmacological experiments as the sensitivity of preparations to
agonists and antagonists is dependent on the amount of stretch.
3.
The active response of a preparation is dependent on the extent of stretch, which makes it important to set
the preparation to an internal circumference or pre-load tension giving maximal response of a given tissue
mounted in the 820MO chambers.
The aim of the normalization procedure is to stretch the mounted muscle segment to an optimal pre-load
tension giving maximum response by muscle contraction. For arteries the.so-called normalized internal
circumference (IC1): defined as a set fraction of the internal circumference (IC100) that a fully relaxed segment
would have at a specified transmural pressure. For small rat arteries the target transmural pressure is typically
100mmHg = 13.3 kPa.
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Summary of Contents for 820MO
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