MITOTIC EFFECTS OF IONIZING RADIATION ON THE MALIGNANT AND NONMALIGNANT EPIDERMIS HYPERPLASIA OF MICE. V. EFFECTS OF SINGLE CONTACT IRRADIATION AFTER 10 DAYS OF PRETREATMENT WITH CARCINOGEN OR TUMOR ENHANCER

Journal Article · Sun Dec 01 04:00:00 EST 1963 · Strahlentherapie (West Germany)

OSTI ID:4104453

Setaelae, K; Lindroos, B; Nyyssoenen, O

The mitotic response to a single exposure of the mouse back to a Sr/sup 90/ + Y/sup 90/ contact source, with a dose rate of about 1000 rad/9 min, was analyzed in two experimentally provoked and in several respects opposite epidermal conditions. Female mice of the skin-tomor-resistant RA strain were pretreated with carcinogen, and with tumor enhancer, respectively, for 10 days, and exposure took place one day after the cessation of pretreatment. In each series and in each animal, 500 mitotic figures (normal and pathologic) and the corresponding number of non-dividing epidermal cells were counted and classified at postexposure hours 1, 3, 6, 12, 24, 48, and 72. The total number of mitoses examined amounted to 102,500 and that of nondividing nuclei to 1,703,277. Conclusions were drawn only when the difference between the corresponding series was highly significant (P < 0.001). It appeared that under the experimental conditions the nature and the degree of severity of the irradiation response were not correlated with the frequency of the mitotic activity (i.e., with the first of the two growth facets), as long as the cell maturation (i.e,, the second growth facet) was normal or nearly normal (benign epidermal hyperplasia provoked by the noncarcinogenic tumor enhancer Tween 60). On the contrary, the condition characterized by a highly significantly lower mitotic rate as well as by delayed and misguided maturation (malignant epidermal hyperplasia provoked by the carcinogen 9,10-dimethyl-1,2-benzanthracene) proved preferentially more vulnerable to irradiation. It also became evident that no single-type of mitotic disturbance was specific of the irradiation response of either epidermal condition. (auth)

• Research Organization: Universitat, Helsinki
• NSA Number: NSA-18-008186
• OSTI ID: 4104453
• Journal Information: Strahlentherapie (West Germany), Journal Name: Strahlentherapie (West Germany) Vol. Vol: 122; ISSN STRAA
• Country of Publication: Country unknown/Code not available
• Language: German

Related Subjects

ANTHRACENE
BENZANTHRACENE
BIOLOGY AND MEDICINE
CANCER
CHEMICALS
CYTOLOGY
DETERGENTS
DISTRIBUTION
DRUGS
EMULSIONS
EPIDERMIS
MICE
MITOSIS
POLYMERS
QUANTITY RATIO
RADIATION DOSES
RADIATION EFFECTS
SEX
SKIN
STRONTIUM 90
TUMORS
VARIATIONS
YTTRIUM 90