Brain cortex mtDNA (LU/ng total patas DNA, mean ± SE) determined by HC-CA. (A) Patas offspring taken at birth after in utero exposure to no drug (n = 4), 3TC (n = 4), AZT/3TC (n = 3), AZT/ddI (n = 3), or d4T/3TC (n = 3). One-way ANOVA showed significant depletion in the NRTI-treated groups compared with the controls (p = 0.01), and the Holm-Sidak method for multiple comparisons showed significant (p < 0.05) depletion in groups exposed to 3TC and d4T/3TC. (B) Patas offspring taken at 1 year of age after in utero plus 6 weeks post-birth exposure to no drug (n = 4), AZT (n = 4), AZT/3TC (n = 3), AZT/ddI (n = 4), or d4T/3TC (n = 4), followed by 46 weeks with no drug exposure. By one-way ANOVA, all the NRTI-exposed groups were significantly (p < 0.001) depleted compared with the unexposed group. Also, by the Holm-Sidak procedure for multiple comparisons, all NRTI-exposed groups were significantly (p < 0.002) depleted in mtDNA compared with the unexposed group.