Effect of Quinine Hydrochloride on Resistance of Rabbit Red Cells. ∗

Abstract

Clinical observations on blackwater fever have suggested either that red cells of an individual treated with large doses of quinine salts are unusually susceptible to intra-vascular lysis, or that quinine salts act as lysins for red cells already weakened by intra-vascular lysins which appear in the disease. The purpose of this paper is to show that red cells of rabbits receiving quinine hydrochloride in proper amount are less resistant to lysins such as saponin and sodium taurocholate used in vitro. The experiments fall into 2 groups: (a) in vitro experiments, which show that quinine hydrochloride is a simple hemolysin, and (b) in vivo experiments, which show that the resistance of the animal's red cells is lessened by the administration of the quinine salt.

(a) In vitro experiments. The time-dilution curve for quinine hydrochloride and rabbit red cells can be found in the usual way, 1 and, at 25°C., is:— Dilution, 1 in 25 30 40 50 60 100 t, minutes 3.0 4.0 9.5 17 25 85

This is a typical time-dilution curve for a simple hemolysin, and the endpoints are sharp and regular. As might be expected, the addition of quinine hydrochloride to systems containing saponin or sodium taurocholate produces a marked acceleration of hemolysis, and this can be measured by the usual methods. 1 If the cells are left in contact with 1 in 100 quinine hydrochloride for 10 minutes (after which time there is no lysis), and then washed and re-suspended, the resulting suspension has a smaller resistance to saponin and taurocholate than has an untreated suspension, and the R-values which measure the acceleration are about 0.78 to 0.75.