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LE 5002 Non Invasive Blood Pressure Meter
USER MANUAL
19
7.4.
RECOMMENDED METHODOLOGY
•
Heat sources such as infrared lamps, hot plates, etc. may be used for
vasodilatation. Nevertheless, with these sources it is sometimes difficult to
control the temperature the animal is submitted to; whereas ventilated heaters
with thermostats offer greater possibilities (PANLAB offers various such
devices in its catalogue).
•
IT IS VERY IMPORTANT to bear in mind that if the animal is overheated, as
shown by sweating, it will be necessary to wait a considerable time before its
pressure can be taken, since it will have been adversely conditioned, giving rise
to an anxiety response.
•
The whole animal, and not just specific areas such as the tail, should be heated.
•
Animals can be preheated in their cages and then placed in the traps, although
always without causing any unnecessary trauma, and giving them time to adapt
to being unable to move. If the traps are not subject to any other heat source the
effect of the vasodilatation will last for some time.
•
It is advisable to cover the animal’s eyes (dark places are reassuring), although
they should be allowed to breathe freely, and any noise that could be an adverse
stimulus avoided.
•
Heating temperature may vary for animals and even different breeds. The
following values are given as guidance only:
RATS:
between 29ºC and 32ºC
MICE:
between 30ºC and 34ºC
Higher values may jeopardise accomplishment of the objective. Experience has shown
us that the best results are obtained by drawing out heating time rather than by
increasing the temperature.
The following description outlines a typical protocol that should provide satisfactory
results in the measuring processes. Naturally, it is offered as an example only, meaning
that the experimenter can make any changes to the methodology presented they deem
necessary depending on their own experience, and apply them to their specific
experimental situation.
The following points should be applied when carrying out vasodilatation.
1.
Over the first few days –three should be more than enough– the animal should
be made accustomed to staying in the trap for thirty minutes with the cuff and
the transducer placed as shown. It may be a good idea to carry out a few
measuring tests to get the animal used to the pressure the system applies to its
tail.
2.
Once this period has elapsed, the system will probably take reliable
measurements. Thus, after 20 min of vasodilatation measurements can begin. If
the measurements are not satisfactory, wait 10 minutes and try again.
Throughout this time, the heart rate should be seen increasing in intensity and stability,
and a constant cadence should be seen in the flashing of the BEAT. Progressive
movement of the LEVEL bar, and stability of the frequency value, which is more
significant, should also be evident.