The effects of hypoxia, hypertrophy, and diet on rat myocardial ornithine decarboxylase activity.

We have shown that there is a highly significant difference between right and left ventricular ornithine decarboxylase activity. The left ventricle had a much higher activity compared with the right ventricle. A restricted diet caused a decrease in ornithine decarboxylase activity after 24 hr. Hypoxia caused a depression of the ornithine decarboxylase activity during the first 2 days of the experiment. In the hypertrophied right ventricle there was an initial decrease in ornithine decarboxylase after 24 hr and then a gradual increase in ornithine decarboxylase activity during the 7 days of the experiment. The increase in ornithine decarboxylase activity became significant when an increase in tissue weight became apparent.