[Stress and hormone]

The history of the studies on stress and hormones is briefly reviewed. The two main stress transmission systems are the endocrine (CRH-ACTH-Cortisol) and the neural (Sympatho-adreno-medullary) systems. The junction of the two systems resides in the hypothalamus. It has been clarified that CRH has central suppressive effects on eating, sleeping and sexual behavior. The relationships between emotions such as fear, anger and neurotransmitters (noradrenaline or serotonin) are discussed. Recent studies have revealed that various kinds of cytokines secreted from leukocytes stimulate the secretions of CRH and ACTH. Thus the cooperative mechanisms and actions of the endocrine, neural and immune systems against stress to keep homeostasis are elucidated.