Differentiated thyroid cancer can be effectively treated with high-dose 131I and the other head and neck cancer can also be effectively treated with extra-radiotherapy, but these treatments often result in a reduction in salivary gland function, causing xerostomia. Collectively, these effects can lead to severe secondary complications, including difficulty in speaking and swallowing, decreasing appetite even affecting nutrition and sleep. Amifostine, an analog of cysteamine, is a phosphorlyated aminothiol prodrug and its active metabolite, WR-1065 etc, can selectively protect normal tissues from the cytotoxic effects of drugs and/or radiation while preserve antitumor effects. Many studies have demonstrated that amifostine protects normal tissues from both acute and late extra-radiation damage without protecting the tumor. It has been approved by FDA to be used for protecting the salivary gland from xerostomia caused by radiotherapy. It has also show protecting effects on intra-radiotherapy, but there are many problems waiting for study.
Amifostine ; adverse effects ; therapeutic use ; Animals ; Clinical Trials as Topic ; Clinical Trials, Phase II as Topic ; Clinical Trials, Phase III as Topic ; Cytoprotection ; Head and Neck Neoplasms ; drug therapy ; radiotherapy ; Humans ; Rabbits ; Radiation Injuries ; prevention & control ; Radiation-Protective Agents ; pharmacology

This study examined whether amifostine (WR-2721) could attenuate memory impairment and suppress hippocampal neurogenesis in adult mice with the relatively low-dose exposure of acute radiation syndrome (ARS). These were assessed using object recognition memory test, the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay, and immunohistochemical markers of neurogenesis [Ki-67 and doublecortin (DCX)]. Amifostine treatment (214 mg/kg, i.p.) prior to irradiation significantly attenuated the recognition memory defect in ARS, and markedly blocked the apoptotic death and decrease of Ki-67- and DCX-positive cells in ARS. Therefore, amifostine may attenuate recognition memory defect in a relatively low-dose exposure of ARS in adult mice, possibly by inhibiting a detrimental effect of irradiation on hippocampal neurogenesis.
Acute Radiation Syndrome/drug therapy/*immunology/psychology ; Amifostine/*pharmacology/therapeutic use ; Animals ; Apoptosis/immunology ; Gamma Rays/*adverse effects ; Hippocampus/immunology ; Immunohistochemistry ; In Situ Nick-End Labeling ; Male ; Memory/*radiation effects ; Mice ; Mice, Inbred ICR ; Neurogenesis/immunology ; Radiation-Protective Agents/*pharmacology/therapeutic use