Biomaterial Database

O6-methylguanine accumulates in DNA of mammary glands after administration of N-methyl-N-nitrosourea to rats. 1979

R Cox, and C C Irving

N-Methyl-N-nitrosourea (MNU) induces mammary carcinoma in female rats when given intravenously. After a single intravenous dose of N-methyl-N-nitrosourea (5 mg/100 g body wt.), we were unable to detect a shift of rat mammary gland DNA on an alkaline sucrose gradient. However, the alkylated products in DNA, 7-methylguanine and O6-methylguanine, were determined at various times following treatment with N-methyl-N-nitrosourea. O6-Methylguanine was removed from the DNA at a slower rate than 7-methylguanine and increased in the DNA with a second injection of N-methyl-N-nitrosourea. 3-Methyladenine was not detected in DNA from the mammary gland of the rat. These data support previous work with brain and bladder that suggest the persistence of O6-methylguanine in DNA might be involved in the induction of cancer by N-methyl-N-nitrosourea.

UI	MeSH Term	Description	Entries
D008321	Mammary Glands, Animal	MAMMARY GLANDS in the non-human MAMMALS.	Mammae,Udder,Animal Mammary Glands,Animal Mammary Gland,Mammary Gland, Animal,Udders
D008325	Mammary Neoplasms, Experimental	Experimentally induced mammary neoplasms in animals to provide a model for studying human BREAST NEOPLASMS.	Experimental Mammary Neoplasms,Neoplasms, Experimental Mammary,Experimental Mammary Neoplasm,Mammary Neoplasm, Experimental,Neoplasm, Experimental Mammary
D008745	Methylation	Addition of methyl groups. In histo-chemistry methylation is used to esterify carboxyl groups and remove sulfate groups by treating tissue sections with hot methanol in the presence of hydrochloric acid. (From Stedman, 25th ed)	Methylations
D008770	Methylnitrosourea	A nitrosourea compound with alkylating, carcinogenic, and mutagenic properties.	Nitrosomethylurea,N-Methyl-N-nitrosourea,NSC-23909,N Methyl N nitrosourea,NSC 23909,NSC23909
D009607	Nitrosourea Compounds	A class of compounds in which the core molecule is R-NO, where R is UREA.	Compounds, Nitrosourea
D001743	Urinary Bladder	A musculomembranous sac along the URINARY TRACT. URINE flows from the KIDNEYS into the bladder via the ureters (URETER), and is held there until URINATION.	Bladder,Bladder Detrusor Muscle,Detrusor Urinae,Bladder Detrusor Muscles,Bladder, Urinary,Detrusor Muscle, Bladder,Detrusor Muscles, Bladder
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D004260	DNA Repair	The removal of DNA LESIONS and/or restoration of intact DNA strands without BASE PAIR MISMATCHES, intrastrand or interstrand crosslinks, or discontinuities in the DNA sugar-phosphate backbones.	DNA Damage Response
D005260	Female		Females