Biology Reference
In-Depth Information
Alternatively, transgenic mice over-expressing Epo only in the
brain (Tg21 mice) or in both brain and plasma (Tg6 mice)
have been generated (
16, 17
) and they represent an interest-
ing tool to study the effect of Epo on the respiratory control.
In addition, since a sex difference exists in the ventilatory pat-
tern, in the ventilatory response to hypoxia, and in Epo impact
on this response, sex of the mice is an important variable and
it should be determined and annotated. Indeed, the experi-
mental groups should be designed in order to equally repre-
sent males and females or, ideally, to consider each gender
separately, in both sampling and analysis.
16. The rectal temperature of mice should be measured before and
after the experimental protocol in order to make corrections
for BTPS conditions in the calculation of
V
T
(cf. Subheading
3.5
,
step 2). The initial body temperature is considered to correct
all the data, except the 5 last minutes (recovery period), which
are corrected by using the mice temperature at the end of the
protocol (the final body temperature).
17. Indeed, the dose- and time-effect of Epo should be firstly
inferred from data available in the literature and/or deter-
mined specifically for the considered experimental context.
The time of injection and the doses regimen of Epo are other
parameters depending on the specific experimental design.
Alternatively, other Epo derivatives are commercially available,
some of them presenting only the non-erythropoietic charac-
teristics of Epo and being a potential useful tool to study the
impact of Epo on the control of respiration. Obviously, control
animals should be injected with the vehicle used to resuspend
the recombinant Epo.
18. The air flow in depends on the size of the animal and the value
proposed here for adult mice has been determined empirically
from our previous experiments.
19. The flow of the subsampling pump should always be a little bit
lower than the air flow in to avoid the creation of a negative
pressure within the plethysmography chamber.
20. In order to facilitate comparisons between mice, minute venti-
lation (
V
V
E
), O
2
consumption (
O
), and CO
2
production
2
V
) are normalized to 100 g body weight. For this reason,
mice should be weighted before the beginning of the
experiment.
21. In addition to severe hypoxia as tested in this example, it is also
possible to test by using a similar procedure the impact of other
gas regimen on ventilation and/or of Epo treatment on venti-
lation (e.g., hyperoxia, normoxia, mild hypoxia, anoxia, hyper-
capnia, normocapnia, hypocapnia).
(
CO
2
Search WWH ::
Custom Search