Proliferative response of the murine esophageal epithelium to radiation: Modification by food consumption patterns

The single layer of proliferative epithelial cells of the murine esophagus undergoes a sequence of damage and recovery following cytotoxic insult. The modification of both damage and proliferative recovery by the alteration of animal eating patterns was investigated following thoracic field irradiation through the determination of /sup 3/H-TdR incorporation into the esophagus along with selective counting of labeled nuclei and mitotic figures. Initial radiation-induced damage, as determined by /sup 3/H-TdR incorporation suppression and mitotic delay, is under normal conditions dependent on the time of day of treatment. This circadian sensitivity may be altered by changing the eating pattern of the animal. The proliferative recovery following single dose irradiation is also dependent on food consumption patterns: fasting immediately following treatment and then refeeding 2 days later results in a more rapid proliferative recovery than observed under control eating conditions, while reduced food consumption during the period of proliferative hyperplasia reduces the extent of recovery. During multifraction radiation schedules both the damage produced by a subsequent dose and recovery capacity are influenced by the food consumption pattern between fractions