Potential of electron transfer and its application in dictating routes of biochemical processes associated with metabolic reprogramming / 医学前沿

Metabolic reprogramming, such as abnormal utilization of glucose, addiction to glutamine, and increased de-novo lipid synthesis, extensively occurs in proliferating cancer cells, but the underneath rationale has remained to be elucidated. Based on the concept of the degree of reduction of a compound, we have recently proposed a calculation termed as potential of electron transfer (PET), which is used to characterize the degree of electron redistribution coupled with metabolic transformations. When this calculation is combined with the assumed model of electron balance in a cellular context, the enforced selective reprogramming could be predicted by examining the net changes of the PET values associated with the biochemical pathways in anaerobic metabolism. Some interesting properties of PET in cancer cells were also discussed, and the model was extended to uncover the chemical nature underlying aerobic glycolysis that essentially results from energy requirement and electron balance. Enabling electron transfer could drive metabolic reprogramming in cancer metabolism. Therefore, the concept and model established on electron transfer could guide the treatment strategies of tumors and future studies on cellular metabolism.

Pharmacokinetics and bioequivalence of nifedipine sustained-release tablets after multiple doses administration in healthy volunteers / 中国临床药理学与治疗学

AIM: To investigate the pharmacokinetic properties and bioequivalence of nifedipine sustained-release tablets after multiple doses administration in healthy volunteers. METHODS: Twenty two male healthy volunteers were enrolled in a randomized two-way crossover design with multiple doses (20 mg·d-1×7 d) study. Nitrendipine was used as the internal standard and the concentrations of nifedipine in plasma were determined by HPLC-APCI-MS. The pharmacokinetic parameters were calculated and the bioequivalence were compared by DAS (ver 1.0) program. RESULTS: The pharmacokinetic parameters of test and reference preparations were as follows: Cmax (52.5±27.4) and (54.0±31.2) ng·ml-1;Cmin (5.4±4.1) and (6.2±5.9) ng·ml-1;Cav (16.8±9.2) and (19.3±12.4) ng·ml-1;Tmax (3.7±0.9) and (4.1±1.1) h;t1/2 (8.9±4.9) and (8.5±3.1) h;AUC0-τ (403.4±221.0) and (461.9±296.6) μg·h·L-1, AUC0-36h (444.4±256.1) and (503.1±330.9) ng·h·ml-1;AUC0-∞ (482.1±268.9) and (542.3±348.4) ng·h·ml-1;DF (299.8±117.7)% and (279.2±97.5)%, respectively. There were no significant differences (P>0.05) in Tmax, Cmax, Cmin, Cav, DF, AUC0-τ, AUC0-36h, AUC0-∞ and t1/2 between the two preparations. The relative bioavailability of test tablets was (100.6±38.6)%. CONCLUSION:The test and reference preparations were bioequivalence.