Therefore, hormones and growth factors that stimulate cellular growth may stimulate PK activity for ATP supply. PK activity was determined in 1 ml of 50 mM tri-ethanolamine buffer, pH 7.5, containing 2.25 M KCl, 0.24 M MgSO4, 6 ^M ADP, 18 U/ml lactic dehydrogenase, 1.4 ^mol NADH, and 5 ^l of follicular supernatant at 340 nm at 37°C. After recording of the background rate of NADH oxidation for 5 min without substrate, 33.3 ^l of a 45 mM phosphoenol pyruvate was added to the mixture and mixed immediately. The rate of NADH oxidation was recorded at 1-min intervals for 5 min. The rate of NADH oxidation was linear during the reaction period, and the enzyme activity was expressed as millimoles NADH oxidized per minute per milligram protein. ampicillin antibiotic
Determination of MDH Activity
MDH in mitochondrial matrix controls the availability of oxaloacetate, a critical factor for the progress of the Krebs cycle. Therefore, factor(s) influencing the MDH activity can alter the rate of ATP generation in cells. Moreover, because the production of ATP by the Krebs cycle depends on the oxidative phosphorylation, increased MDH activity will indicate increased mitochondrial activity as well as the maturation of glucose metabolic pathways in cells.