Biomaterial Database

The effect of dose fractionation on radiation injury in the rat stomach. 1993

N Breiter, and T Sassy, and K R Trott

Institute of Radiobiology, GSF, Neuherberg, Germany.

Localized 300 kV X-irradiation of the rat stomach with single and fractionated (two and five fractions given daily and in 4 weeks) doses was performed. In the second and third week after irradiation acute radiation gastritis developed which resulted in a dose-dependent drop in body weight. The alpha/beta value for a 10% drop in body weight was calculated to be 9.6 Gy (95% confidence interval 2.1-25.9 Gy). Between 4 and 40 weeks after irradiation subchronic radiation damage was observed which presented itself as atonic dilatation of the stomach. For this effect, the alpha/beta value is 4.8 Gy (graphical estimation) and 5.3 Gy (95% confidence interval 0.4-13.1 Gy; direct Poisson model). In the five-fraction (5F) experiment a significant increase in tolerance amounting to 0.8 Gy/day for the acute effect and 0.4 Gy/day for the subchronic effect was observed when intervals were increased from 1 day to 1 week. In a separate experiment animals were pre-irradiated with subtoxic and toxic radiation doses. One hundred days later acute tolerance to a second irradiation was completely restored. However, no recovery of subchronic damage was observed.

UI	MeSH Term	Description	Entries
D011829	Radiation Dosage	The amount of radiation energy that is deposited in a unit mass of material, such as tissues of plants or animal. In RADIOTHERAPY, radiation dosage is expressed in gray units (Gy). In RADIOLOGIC HEALTH, the dosage is expressed by the product of absorbed dose (Gy) and quality factor (a function of linear energy transfer), and is called radiation dose equivalent in sievert units (Sv).	Sievert Units,Dosage, Radiation,Gray Units,Gy Radiation,Sv Radiation Dose Equivalent,Dosages, Radiation,Radiation Dosages,Units, Gray,Units, Sievert
D011833	Radiation Injuries, Experimental	Experimentally produced harmful effects of ionizing or non-ionizing RADIATION in CHORDATA animals.	Experimental Radiation Injuries,Injuries, Experimental Radiation,Experimental Radiation Injury,Radiation Injury, Experimental
D001835	Body Weight	The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.	Body Weights,Weight, Body,Weights, Body
D005260	Female		Females
D005756	Gastritis	Inflammation of the GASTRIC MUCOSA, a lesion observed in a number of unrelated disorders.	Gastritides
D000208	Acute Disease	Disease having a short and relatively severe course.	Acute Diseases,Disease, Acute,Diseases, Acute
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013270	Stomach	An organ of digestion situated in the left upper quadrant of the abdomen between the termination of the ESOPHAGUS and the beginning of the DUODENUM.	Stomachs
D015996	Survival Rate	The proportion of survivors in a group, e.g., of patients, studied and followed over a period, or the proportion of persons in a specified group alive at the beginning of a time interval who survive to the end of the interval. It is often studied using life table methods.	Cumulative Survival Rate,Mean Survival Time,Cumulative Survival Rates,Mean Survival Times,Rate, Cumulative Survival,Rate, Survival,Rates, Cumulative Survival,Rates, Survival,Survival Rate, Cumulative,Survival Rates,Survival Rates, Cumulative,Survival Time, Mean,Survival Times, Mean,Time, Mean Survival,Times, Mean Survival
D017208	Rats, Wistar	A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.	Wistar Rat,Rat, Wistar,Wistar Rats