Vitamin A: Probe of immune complement reactions—III inhibition of guinea pig complement hemolysis

Abstract The vitamin A inhibition of guinea pig complement-mediated hemolysis has been further examined. The results of a dose—response curve with retinal suggest that a single molecule of retinal per hemolytic site is sufficient to inhibit the reaction. It also appears that under our conditions a fraction of the lytic sites is not susceptible to inhibition. The inhibition is markedly pH dependent. The consumption of Cl by EAC4 is unaffected by retinal, while the consumption of C2 by EAC14 is diminished.