Figure 8
Treatment of STZ-diabetic rats with LA enhances the bioenergetic function of rat liver mitochondria; comparison with in vitro treatment of the mitochondria with DHLA. (A–B) Comparison of the respiratory reserve capacity (FCCP-induced increments in oxygen consumption rate (OCR)) of rat liver mitochondria isolated from control animals or from STZ-diabetic animals treated with either vehicle or LA in vivo, with or without additional in vitro preincubation with DHLA (100 nmol/L) in mitochondrial coupling assay experiments. The height of each bar corresponds to the magnitude of the increase in respiratory reserve capacity by the indicated condition, expressed as delta AUC. Please note that the most pronounced enhancements in 3-MP-induced bioenergetic responses were seen in the presence of LA or LA + DHLA pretreatments. When these treatments were applied, the 3-MP bioenergetic responses of the STZ-diabetic rats became higher than the responses of the corresponding nondiabetic controls, indicating that these treatments tended to restore normal mitochondrial functionality. Please also note that LA treatment of the STZ-diabetic rats (but not the control rats) increased mitochondrial function in the absence of any 3-MP addition. *p < 0.05 and **p < 0.01 show significant enhancements of FCCP-induced OCR responses by the indicated agents (in vitro 3-MP; in vitro DHLA in the presence of in vitro 3-MP; in vivo LA; in vivo LA, followed by the addition of in vitro DHLA; in vivo LA, followed by the addition of in vitro 3-MP; in vivo LA, followed by the addition of in vitro DHLA and 3-MP) compared with FCCP alone in the respective (control or STZ-diabetic) mitochondria; #p < 0.05 and ##p < 0.01 show significant enhancements of FCCP-induced OCR responses by in vitro 3-MP or in vitro DHLA and 3-MP in combination, when compared with the responses of the respective (control or STZ-diabetic) mitochondria isolated from LA-treated rats. Bar graphs show mean ± SEM values of at least n = 4 experiments for each condition.