Oxidative Stress and Species Differences in the Metabolism, Developmental Toxicity, and Carcinogenic Potential of Methanol and Ethanol - The Toxicology of Methanol - page 180

TABLE 7.4 Changes in ADH1 Activity Throughout Development in
Mice, Rats, and Humans
Model Age Organ Activity of ADH1 Citation

Mouse 7-12 somites Whole

embryo

0.1-0.3 nmol/min/mg
protein

Harris et al.
(2003)

20-22
somites

Whole
embryo

0.5 nmol/min/mg
protein

Harris et al.
(2003)

Adult Liver 1360 nmol/min/mg

protein

Algar et al.
(1983)

Rat 7-12 somites Whole

embryo

0.25-0.6 nmol/min/mg
protein

Harris et al.
(2003)

20-22
somites

Whole
embryo

0.49-0.62 nmol/min/mg
protein

Harris et al.
(2003)

Human Fetus 2-6

months

Liver 149mU/g liver wet

weight

Pikkarainen
and Raiha
(1967)

Infant 0.3-7
months

Liver 579mU/g liver wet

weight

Pikkarainen
and Raiha
(1967)

Children and
adults 2-50
years

Liver 2410mU/g liver wet

weight

Pikkarainen
and Raiha
(1967)

adulthood. However, human ADH1 activity is consistently higher than
that found in both mice and rats (Table 7.4).

7.2.1.2 Catalase Catalase (EC 1.11.1.6) is a tetramer containing four
strongly bound molecules of nicotinamide adenine dinucleotide phos-
phate (NADPH) (Kirkman and Gaetani, 1984). Each tetrameric unit
contains four heme groups, which determine the function of the enzyme
on the basis of their redox state. Consequently, catalase can exist in three
states: (1) the resting state (containing ferric heme groups), which is
responsible for the antioxidative activity of catalase; (2) Compound I
(containing Fe 4 þ heme groups), which is responsible for the peroxidative
activity of catalase; and (3) Compound II, which is the inactive formof the
enzyme (Goyal and Basak, 2010). The tightly bound NADPH molecules
prevent the formation of Compound II (Kirkman and Gaetani, 1984).