Abstract
The time of blending the rickettsial inoculum, as also the strain of hen's egg employed, influenced the degree of infection which developed in fertile eggs after the injection of typhus rickettsiae into the yolk sac. By varying these factors, maximal or minimal infections could be obtained. Eggs incubated at 40°C. developed only minimal rickettsial infection, whereas control eggs incubated at 37.5°C. became heavily infected. Potassium cyanide markedly enhanced rickettsial growth in experiments in which the control eggs developed only minimal infection. Under circumstances such that the control eggs became heavily infected, KCN had no appreciable effect. Toluidin blue and methylene blue delayed the development of rickettsial infection in the yolk sac, but their rickettsiostatic action under the conditions of these experiments was less marked than that of penicillin and para-aminobenzoic acid. The rickettsiostatic action resulting from temperature elevation was neutralized by KCN, and hence is believed to be due to the increased activity of the cyanide-sensitive respiratory enzyme (cytochrome oxidase) in the entodermal cells in which the rickettsiae multiply. The rickettsiostatic action of toluidin blue and methylene blue, though probably also resulting from increased metabolic activity in the entodermal cells, was not neutralized by KCN. This observation is in harmony with the reported observation that dyes of this type furnish an alternative mechanism for intracellular oxidation which is cyanide-insensitive. The rickettsiostatic action of para-aminobenzoic acid was not neutralized by KCN. No conclusions can be reached at present concerning the mechanism of action of this compound. Dinitrophenol and several compounds related to para-aminobenzoic acid gave negative results.
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Selected References
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- Greiff D., Pinkerton H., Moragues V. EFFECT OF ENZYME INHIBITORS AND ACTIVATORS ON THE MULTIPLICATION OF TYPHUS RICKETTSIAE : I. PENICILLIN, PARA-AMINOBENZOIC ACID, SODIUM FLUORIDE, AND VITAMINS OF THE B GROUP. J Exp Med. 1944 Dec 1;80(6):561–574. doi: 10.1084/jem.80.6.561. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Harrop G. A., Barron E. S. STUDIES ON BLOOD CELL METABOLISM : I. THE EFFECT OF METHYLENE BLUE AND OTHER DYES UPON THE OXYGEN CONSUMPTION OF MAMMALIAN AND AVIAN ERYTHROCYTES. J Exp Med. 1928 Jul 31;48(2):207–223. doi: 10.1084/jem.48.2.207. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Moragues V., Pinkerton H. FATAL MURINE TYPHUS INFECTION IN THE dba STRAIN OF MICE, WITH OBSERVATIONS ON STRAIN VARIATION IN SUSCEPTIBILITY. J Exp Med. 1944 Jan 1;79(1):35–40. doi: 10.1084/jem.79.1.35. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Romanoff A. L. DEVELOPMENT OF HOMEOTHERMY IN BIRDS. Science. 1941 Aug 29;94(2435):218–219. doi: 10.1126/science.94.2435.218. [DOI] [PubMed] [Google Scholar]