Abstract
Histological and histochemical observations of the lesions under states of urticaria acuta, chronica and factitis as well as of urticarial wheal were made consequtively on the skin specimens taken directly from the locci of the axillary region where histamine, sinomenine or one of the several of other kinds were injected inra-dermally. Through the results obtained, the authors concluded that an antigen antibody reaction carried out into effect locally should cause a degranulation on mast cells of capillary walls releasing histamine or heparin. An action of these substances on minute vessels in papillary area should cause temporally constriction which results in relaxation or dilatation of lymphatic space around capillaries, formation of urticarial wheals being developed. These phenomena seem to be similar to those observed by Rossle-Frohlich's school on pieces of frog mesenterium under conditions of tissue anaphylaxis. Lewis' opinion that vasoconstriction should be an initiating and basic mechanism about urlticarial wheal formation might be founded with the results given by the authors.
