The Effect of Continuous Irradiation on Cell Proliferation and Maturation in Small Intestinal Epithelium

Abstract

Autoradiographic studies and scintillation counting of crypt material after pulse labelling with 3H‐thymidine showed that during continuous irradiation with 290 rads/day a reduced proliferative activity is present in the crypts of rat small intestine after 1 day of irradiation and of normal activity during the remaining period (5 days) irradiation. After cessation of irradiation an increase in proliferative activity can be observed after 1 day of recovery. From the time (36–48 hr after starting of the irradiation) that the number of villus cells is reduced an expansion of the proliferation zone in the crypt was observed. Both effects last until 1 day of recovery after cessation of irradiation. The process of crypt cell maturation and of villus cell function has also been studied during and after continuous irradiation by micro‐chemical enzyme analyses in isolated crypts and villi. It was found that the expansion of the proliferation zone in the crypt is accompanied by a decrease in activity of only those enzymes (i.e. non‐specific esterases) which normally become active during crypt cell maturation. The activity of enzymes normally present mainly in the functional villus cells remained relatively unaffected by changes in crypt cell kinetics. A hypothesis of different regulation mechanisms of the proliferative activity in the intestinal crypt and a possible explanation of the different behaviour of various enzyme activities as a result of changes in crypt cell proliferation is discussed.

Type I Interferons Link Viral Infection to Enhanced Epithelial Turnover and Repair

“…Damaged epithelial cells must be shed and rapidly replaced with new cells generated by self-renewing stem cells (Blanpain et al, 2007). Examples of damage that can alter turnover rates include irradiation, malnutrition, and bacterial and parasitic infection (Cliffe et al, 2005; Creamer, 1967; Luperchio and Schauer, 2001; Rijke et al, 1975). …”

Déterminisme neuro humoral de l'adaptation de l'intestin résiduel après entérectomie

“…Si celui-ci semble concerner l'organisme entier (Laplace, 1975a et (Lipkin, 1973 ;Tutton, 1977 ;Pansu, Bérard et Lambert, 1977 ; Bergeron, 1978 ;Lankisch, 1980 ; Bastie, 1981 Sprinz, 1963 ; Guenet, 1973 (Galjaard, Meer-Fieggen et Giesen, 1972 ; Rijke, Meer-Fieggen et Galjaard, 1974). Une réponse analogue est enregistrée après irradiation continue (Rijke et al, 1975) unique (Potten et Hendry, 1975) (Bullough, 1975 (Schofield, 1960). Des interconnexions locales nombreuses sont présentes dans le plexus sous muqueux (Feher, 1976) (Missen, 1976).…”

Radiation-enhanced differentiation of erythroid progenitor cells and its relation to reproductive cell death

“…There are observations in oth er m am m alian tissues and cell lines w hich indicate, or could be interpreted as radiation-induced enhancem ent of differentiation as well: intestinal epithelium (Sherm an and Q uastler 1960, Rijke et al 1975), squam ous cell carcinom a (Glu È cksm ann 1974), neuroblastom a cells (P rasad 1975), ® broblasts (R odem ann et al 1991), and erythroleukaem ic cells (Schwenke et al 1995). This suggests th at enh anced differentiation is not a special erythroid reaction , but seem s to be a general tissue respon se to ionizing radiation.…”