1997 年 7 巻 3 号 p. 131-138
Cytokines are a series of small polypeptides which play important roles in bodie's defense system and homeostasis. Many kinds of cytokines are produced from a variety of cell types and they function through autocrine, paracrine and endocrine mechanisms. Cytokines regulate the growth, differentiation and migration of cells and they are involved in the immune response, inflammation, wound healing and erythropoiesis of the body. Moreover, cytokines affect the tumor growth and metastasis. Cytokines exhibit their function in either negative or positive manner. Cytokines bind specific membrane receptors and elicit physiological functions through the receptor-mediated signaling pathway. To date, nearly 100 cytokines have been reported and their list is still increasing. Thus, it is difficult to review all the cytokines but we classified major cytokines (about 50) into six groups based on their producing cell types and common functions. Wound healing was described with respect to cytokine's interplay in physiology and the EGF receptor system was discussed as a typical example of the molecular mechanisms of signaling pathway.