Target Discovery and Validation Reviews and Protocols

Heart Failure and Immunity 271
We have used a mouse model of postinfarction congestive heart failure combined
with various in vitro techniques to specifically study the contribution of
cytokines and thereby try to delineate the mechanism whereby heart failure may
hamper normal hematopoiesis (11,12). Because we are investigating various
aspects of inflammation on heart failure and hematopoiesis, the careful selection
and handling of the experimental animals are particularly important to
avoidance of undesirable confounding effects. This approach relies on first
inducing heart failure by ligation of the left coronary artery to produce an acute
myocardial infarction. Heart failure also may be induced by aortic banding,
atrial pacing or injection of the right ventricular depressant monocrotaline.
After development of overt heart failure, which usually lasts approx 4–6 wk, the
animals are sacrificed, and blood and bone marrow samples are collected. Then,
in vitro methods are used to pinpoint the contribution of various molecules, e.g.
cytokines, to growth and viability of hematopoietic progenitor cells. Importantly,
the development of overt heart failure also can be manipulated in vivo by either
direct injection of putative regulatory molecules or constant delivery via
implanted osmotic minipumps. Here, we present important aspects of this strategy
with particular emphasis on adequate handling of the animals and ways of identifying
putative inhibitors of hematopoiesis in heart failure mice.
2. Materials
2.1. Experimental Animals
For our studies, we have used adult 6- to-8-wk old Balb/c mice (see Note 5).
Consent from appropriate ethics committees before commencing the actual
experiments is mandatory because these experiments involve induction of a
serious and lethal disease.
2.1.1. Health Monitoring
Because most infections in laboratory animals are subclinical, the animals
and biological material to be used must be tested before the experiments. It is
therefore vital to have a sentinel animal program and test regularly for parasitical,
bacterial, and viral agents according to the needs of the experiment in
question or by following the recommendations of the Federation of European
Laboratory Animal Associations (FELASA) (13).
2.1.2. Testing of Biological Material
Biological material, such as tumor cell lines, may be tested in antibody
production tests, where the biological material is given via different ports of
entry (per os, intraperitoneal, intravenous, subcutaneous, and intranasal) to
clean animals placed in an isolator. The animals are kept in the isolator for a