Table 4.

Quantities (mol/g of Tissue) of Normal and Oxidized Pyrimidines in a Rat Brain Extract Measured Using Isotope-Labeled Standards^a

compound	moles of free bases/g of tissue
uracil	1.20 ± 0.11 × 10−08
thymine	9.01 ± 0.46 × 10−10
cytosine	1.18 ± 0.15 × 10−09
5-methylcytosine	2.90 ± 0.13 × 10−11
5-formylcytosine	1.21 ± 0.15 × 10−09
5-hydroxymethyluracil	6.58 ± 0.37 × 10−11
5-carboxyuracil	8.76 ± 0.05 × 10−10
6-carboxyuracil	7.11 ± 0.08 × 10−10
5-hydroxymethylcytosine	7.77 ± 0.10 × 10−11
5-carboxycytosine	<1.14 × 10−13

^aThe data represent the average and standard deviation (SD) values from three different injections.