Mitsuzo Takagi

Investigation on an Intracellular Hemolytic Agent of Vibrio parahaemolyticus: Lipid Fraction of Dried Cells

The dried cells of two strains of Vibrio parahaemolyticus were fractionated by extracting first with water and then with organic solvents. The hemolytic activity of the fractions was determined, and some of them were assayed for their effect in mice. The hemolytic agent present in the water‐insoluble fraction was extractable in organic solvents such as 70% aqueous ethanol, chloroform–methanol–water (1:2:0.8) and acetone. The extracts showed no toxic effect in mice after intraperitoneal inoculation. No hemolytic activity was observed in the remaining cell residue, which bore the toxicity.

Studies on toxicities of biphenyl ether herbicides and their analogues to fish. I. The methemoglobin-formation by the nitroso-derivatives in white-spotted char, Salvelinus leucomaenis, erythrocytes.

The methemoglobin formation by the nitroso-derivatives of biphenyl ether herbicides (2, 4-dichloro p-nitrobiphenyl ether and 2, 4, 6-trichloro p-nitrobiphenyl ether) and their analogues was investigated in suspensions of white-spotted char erythrocytes. All of the nitroso-derivatives used, induced the methemoglobin formation in white-spotted char erythrocytes as well as human erythrocytes and the activity of methemoglobin formation among the nitroso-derivatives was the most potent in nitrosobenzene followed by p-nitrosobiphenyl ether, 4-chloro p-nitrosobiphenyl ether, 2, 4-dichloro p-nitrosobiphenyl ether and then 2, 4, 6-trichloro p-nitrosobiphenyl ether in erythrocytes of both species. This order among the nitroso-derivatives was dependent on the number of chlorine rather than on its position of substitution in the phenoxy group. The mechanism of methemoglobin formation by the nitroso-derivatives was similar in erythrocytes of both species and on the requirement of NADPH-dependent enzyme systems, and that of methemoglobin reduction was similar, too, on reception of NADH-dependent enzymatic process.