L-arginine Solution Research Articles

Enhancement by l-glutamate and l-alanine of arginine protection against hydrazine toxicity

Pretreatment of mice with intraperitoneally administered solutions of l-arginine or l-glutamate decreased significantly the incidence of seizures and the lethality of single doses of hydrazine. Also there was some protection against lethality and attenuation of speed of toxic action of hydrazine after pretreatment with l-alanine. Protection given by mixtures of any two of the above amino acids appeared to be superior to that given by one alone. A remarkable protective effect was given by a mixture of l-arginine, l-glutamate, and l-alanine (4 mmoles/kg each). The above mixture gave significant protection when injected 3 min after a dose of hydrazine which killed 100% of the controls, but not when given at later times.

PHYSIOLOGY OF THE SPORULATION PROCESS IN CLOSTRIDIUM BOTULINUM. II. MATURATION OF FORESPORES.

Day, Lawrence E., (Michigan State University, East Lansing) and Ralph N. Costilow. Physiology of the sporulation process in Clostridium botulinum. II. Maturation of forespores. J. Bacteriol. 88:695-701. 1964.-Clostridium botulinum, strain 62-A, did not sporulate endotrophically, but forespores matured to refractile, heat-resistant spores when replaced in solutions containing l-alanine and l-proline, l-isoleucine and l-proline, or l-alanine and l-arginine. Solutions of l-arginine or l-citrulline would not support the maturation process. Acetate, CO(2), and delta-amino valeric acid were produced during sporulation in a replacement solution of l-alanine and l-proline, indicating the operation of the Stickland reaction. There was no large uptake of either exogenous l-alanine or acetate during this process. Similarly, there was no apparent protein or nucleic acid synthesis, since high levels of chloramphenicol, 8-azaguanine, or mitomycin C failed to inhibit, and no significant amount of P(32) was incorporated into the spore nucleic acids. Dipicolinic acid (DPA) was synthesized during forespore maturation. It is believed that these final steps in sporulation of C. botulinum require only an exogenous source of energy which can be obtained via the Stickland reaction system, and that the synthesis of DPA and other unknown materials relies primarily on endogenous substrates.

Interactions of testosterone with amino acids

The solubility of testosterone in buffered solutions of 18 l-amino acids was determined. In solutions of l-tryptophan, l-tyrosine, l-phenylalanine, l-histidine, l-arginine, and l-lysine a significant increase was obtained above that observed in buffer alone at the corresponding ionic strength. The largest effect was obtained with l-tryptophan. A slight increase in solubility was noted in solutions of l-methionine and l-proline. With the other ten amino acids no increase was noted.