Abstract
Appetite and feeding behavior are the most important sense and behavior for the maintenance of one's life. Ghrelin is a peptide that has been discovered as an endogenous agonist of the promotion factor receptor for growth hormone secretion. Manifestation and secretion of ghrelin increase by fasting and decrease by ingestion, and the exogenously administered ghrelin increases appetite. In addition, it is involved in various actions such as growth, bowel motility, respiratory function, cardiac activity, carbohydrate metabolism, immunocompetence, affection, cognitive function and generation. Moreover, clinical applications of ghrelin to diseases such as anorexia nervosa, functional gastrointestinal symptoms and cancer cachexia are anticipated. In recent years, the fact that Rikkunshito has an effect to enhance ghrelin signal attracts researchers' attention. Ghrelin, which has various effects as physical and mental hormone, will rise its significance in psychosomatic medicine.
