The invention of the present patent application provides, a
histamine-hyperproductive animal, which is a non-human animal or progeny
thereof obtained by ontogenesis of totipotent cell transfected with a
polynucleotide encoding histidine decarboxylase and has the above
polynucleotide in the cellular chromosome to produce histamine at a high
level in the somatic cells. Thus, analysis of the pathogenesis and
pathological consequence in various disorders associated with histamine
in human as well as development of therapeutic techniques and remedies
for these disorders will be developed.