The Possible Relationship Between Absorption of B. Welchii Toxin and Pernicious Anemia. ∗

Abstract

The experiments reported here are in continuation of our investigation of the possible relationship between the absorption of B. welchii toxin from the intestine, and the condition of pernicious anemia. In a previous communication 1 there was described a severe type of anemia produced in monkeys by the intravenous inoculation of small doses of potent B. welchii toxin. In all the animals, however, after 3 weeks treatment, an immunity became apparent which was not broken down even by a greatly increased dosage, although abnormalities of erythrocytes and a leucopenia persisted for some time.

It was next attempted by the continued inoculation of dosages of B. welchii toxin just below the limit of toleration, to cause such serious injury to the hematopoietic system as might prove irreparable, and to induce a progressive degenerative condition resembling that of pernicious anemia. The method of toxin preparation was essentially as described heretofore, except that somewhat larger pieces of fresh sterile pigeon muscle were added to the casein digest broth. Employing our pernicious anemia B. welchii strain, “Navitol”, sterile toxins were obtained which were lethal for pigeons within 24 hours after intramuscular inoculation of 0.5 cc. Two young ring-tail monkeys (Cebus capucinus) were given a long series of intravenous toxin inoculations in dosage sufficient to keep the animals in a condition of more or less severe anemia for 9 to 10 weeks, in contrast with the 3 or 4 weeks period of the previous experiment. After about 10 weeks, however, in spite of greatly increased dosage, it was not possible to check the tendency of reversion toward normal, and we became convinced that intravenous inoculations of B. zerelchii toxin would not damage the hematopoietic tissues to such a degree that the condition was irreversible.