The method for continuous-flow assay of aspartate aminotransferase with the Technicon SMAC was modified to include preincubation of the serum enzyme with pyridoxal 5'-phosphate, to be consistent with the recommendations of IFCC and the Standards Committee of AACC. Preliminary estimates of the imprecision of the modified method on SMAC gave day-to-day standard deviations of 5.3 U/L at mean of 48...

1. The growth of Avena coleoptile sections in sucrose and auxin solutions is inhibited by various substances which are known to act as dehydrogenase inhibitors. 2. Iodoacetate, which is particularly active in this connection, inhibits all growth at a concentration of 5 x 10(-5) M, but produces only a slight inhibition of oxygen uptake. 3. The growth inhibition by iodoacetate is completely remov...

In 1969 it was dem onstrated1 that pyruvate kinase binds to Blue Dextran 2000. In a study of the mechanism of this absorption it could be shown that the binding of the enzyme is due to an inter­ action of the enzyme with the blue dye of Blue Dextran 2000 and not with the dextran itself. This property was used for the purification of pyruvate kinase of yeast1 and later on also applied to the ex­...

demonstrate that molecular hydrogen but not molecular nitrogen inhibits the splitting of H2 from pyruvate by Clostridium pasteurianum. The effect of H2 is similar to that observed by Kubowitz (Biochem. Z., 274, 285, 1934) with Clostridium butyricum and probably merely reflects a shift in the equilibrium of the reaction. The findings were not affected by substituting argon for the helium. From t...

An extremely thermophilic archaeon, strain ST557T (T = type strain), was isolated from a deep-sea hydrothermal vent in the North Fiji Basin. This strain is a strictly anaerbic coccus whose cells are about 0.8 to 2 microns in diameter. The optimum temperature, pH and sea salt concentration for growth are 85 degrees C, 8.5, and 20 to 40 g/liter, respectively. Strain ST557T grows preferentially in...

We investigated the temporal relationship between hepatic glycogen depletion and cardiac and hepatic PDH (pyruvate dehydrogenase complex) activities during the acute phase of starvation. There was a striking correlation between the decline in hepatic glycogen and PDH inactivation during the first 10 h of starvation. Re-feeding after 6 h starvation was associated with complete re-activation of P...

Interference with the removal of oxaloacetate through citrate formation would naturally impair the catalytic oxidation of pyruvate. The inhibition of oxygen uptake stimulated by aspartate may well be another consequence of the same effect. A similar explanation can be offered for the inhibitory effect on glutamate oxidation, since oxobutyrate inhibits the removal of oc-oxoglutarate as well. a-O...

When Lactococcus lactis was grown in various complex or synthetic media, the fermentation of glucose remained homolactic whatever the medium used, with a global carbon balance of about 87%. Moreover, the nitrogen balance was not equilibrated, indicating that some amino acids led to the production of unknown nitrogen-containing carbon compounds while part of the glucose might contribute to anabo...

In the dog a reduction of mean arterial pressure to 40-50 mm Hg decreased MAC by 20+/--EM 4% in the 1st hour. No further change resulted during the ensuing 3 h of hypotension (40-50 mm Hg). Arterial and cerebrospinal fluid lactate and pyruvate concentrations were not affected by hypotension, nor did cerebrospinal fluid pH decrease. In a separate group of dogs, we reduced arterial pressure to 40...