Observations on the Fate of Vertebrate Erythrocytes and Hemoglobin Injected into the Blood of the American Cockroach, ( Periplaneta americana L.)

Abstract

Erythrocytes from pigeon, cow, rat, and man were injd., both as citrated whole blood and as suspensions in Ringer''s soln., in more than 200 insects in doses of 20 [mu]1. of blood or suspension per insect. Each injn. was carried out under standard aseptic conditions. No shock effect was observed with the initial injns. but the cockroaches showed definite weakness within 24 hrs. Successive blood cell counts on individuals showed a significant decrease in phagocyte number and the remaining phagocytes were blocked with erythrocytes and were in process of disintegration. Decrease in phagocytes was always accompanied by a sharp increase in numbers of a large, capsulate, rod-shaped bacterium in the blood. Injd. insects died within 72 hrs.; death was attributed to septicemia. Injn. of citrated plasma, hemoglobin in physiol. saline, hemoglobin in distilled water, or laked blood with stroma in distilled water, showed none of the above effects. It is concluded that vertebrate erythrocytes are very effective in blocking and destroying the phagocytic cells of the cockroach; that the principal function of these latter cells is phagocytosis; and that regeneration of these cells is very slow. Hemoglobin in soln. appears to be physiologically inert, is not excreted rapidly, and is suggested as an excellent dye for blood vol. detn.