Addition Of Sodium Ions Research Articles

The effect of sodium on the fermentation of glutamic acid by [formula omitted

The anaerobe Peptococcus aerogenes degrades glutamic acid to carbon dioxide, acetic and butyric acids and ammonia (Whiteley 1957). Horler, Westlake and McConnell (1966a) have shown using specifically labelled glutamic acid-14C that carbon five is converted to carbon dioxide and that butyric acid can be formed from the first four carbons of glutamic acid without passing through two carbon units. Washed cells of P. aerogenes , when suspended in a potassium phosphate buffer system at pH 7, readily fermented sodium glutamate; when glutamate was added as the free acid such preparations metabolized only about 10% of the added substrate. The addition of sodium ions, e.g. sodium sulphate, resulted in rapid and complete utilization of the glutamic acid. This paper describes the affect of sodium ions on the metabolism of glutamic and other amino acids by P. aerogenes .

The mechanism of muscle-fiber relaxation adenosine triphosphatase and relaxing activity of the sarcotubular system

A subcellular fraction from frog skeletal muscle, composed of fragments originating from the sarcotubular system, is shown to induce inhibition of the myofibrillar ATPase. No relaxing activity is found in the fractions composed of mitochondrial fragments. The relaxing activity of the Kielley and Meyerhof ATPase preparation could be attributed to the large number of sarcotubular vesicles present in the preparation. It is concluded that the sarcotubular system is the only site in the muscle cell where the relaxing factor is produced. The functional relation between ATPase and relaxing activities was studied by testing the effect of several physical and chemical agents on the rate of both activities. ATPase and relaxing activities were both found to be stimulated by addition of sodium ions and inhibited by the addition of Ca 2+, Atebrine, and after ultraviolet irradiation. Addition of FMN of FAD, in the presence of Atebrine or after irradiation with ultraviolet violet light, results in a complete restoration of ATPase and relaxing activities. Stimulation of the myofibrillar ATPase activity by ultraviolet irradiation is found in frog myofibrils suspension. In these preparations a contamination from residues of the sarcotubular system is demonstrated. Addition of 5 m M Amytal, which does not interfere either with the myofibrillar or the sarcotubular ATPase, results in a complete inhibition of the relaxing activity. From the above findings the hypothesis is developed that the sarcotubular system inhibits the interaction between myosin and actin by means of a phosphorylated high-energy intermediate synthesized through the operation of the sarcotubular ATPase. The evidence in favour of this hypothesis is discussed.

Toxicologic studies on paralytic shellfish poison

The acute LD 50's for a highly purified preparation of paralytic shellfish poison in mice were determined for the oral (263 μg/kg), intraperitoneal (10.0 μg/kg), and intravenous (3.4 μg/kg) routes. Female mice were more susceptible than males to lethal doses of the poison. Increases of pH of the injection medium or the addition of sodium ions reduced the intraperitoneal toxicity. These two effects were not additive and the sodium effect appeared to be the stronger. The sodium ion did not influence the oral or intravenous toxicity. The use of the median death time as a criterion of toxicity is not reliable at pH levels above 4.0 or in the presence of sodium ions above 0.1 M. However, under the specified conditions of the bioassay procedure of the Association of Official Agricultural Chemists, satisfactory results are obtained.

Equilibria of frog nerve with different external concentrations of sodium ions.

Equilibria of frog nerve with different external concentrations of sodium ions.