JP2655343B

PURPOSE:To provide the subject radiation injury protecting agent effective in promoting the natural protecting function of a living body by using an active component comprising a nonapeptide, its derivative and its salt having high safety, originated from nature and known as a serum thymic factor. CONSTITUTION:The objective preventive or remedy for protecting a body from various injury caused by X-ray, gamma-ray, ultraviolet ray, etc., contains, as an active component, a nonapeptide having the amino acid sequence of formula, its ester at the carboxyl group of the C-terminal asparagine, its amide or their pharmacologically permissible salts. The radiation dose applicable to the diseased part in radiotherapy can be remarkably increased by the use of the protecting agent and the hemopoietic function disorder caused by the radiation can be restored by this agent.