Fig. 3.

Comparison of DLDH dehydrogenase activity measured spectrophotometrically. The spectrophotometric measurement was performed by monitoring the increase of NADH absorbance at 340 nm upon DLDH-mediated, NAD⁺-dependent oxidation of dihydrolipoamide (the forward reaction). A solution containing all assay components except mitochondrial sample was used as the blank. The dehydrogenase activity value was derived from the ratio between the enzyme unit and the corresponding protein’s content that was determined densitometrically as shown in Fig. 1B. Data, expressed as percentage of the values for 10 days of age, are mean ± SEM of three animals for each age group. *p < 0.05 (20-day vs. 10-day), **p < 0.05 (30-day vs. 20-day), and ***p < 0.05 (60-day vs. 30-day) all indicate statistical significance (Welch’s t test).