Ornithine Decarboxylase (ODC) Activity in the Liver of Individual Medaka (Oryzias latipes) of Both Sexes

Ornithine decarboxylase (ODC) activity has been determined in the liver of individual medaka (N = 48). The results indicate a mean ODC activity of 1.69 ± 1.77 nmol 14CO2/hr/mg protein. The fish displayed a large interindividual variation of normal ODC activity with a range of 140fold. However, no sex differences were observed. The findings also indicate that the mean ODC activity in this fish model is approximately 100fold greater than observations in the published literature as well as in our laboratory for commonly employed rodent models.