Membrane stabilizing effect of lysolecithin in calf red blood cells.

Lysolecithin sensitivity of red blood cells of 4--6 weeks old calves and 5--10 years old cattles was compared in the presence of 1 and 10 microM lysolecithin. When the incubation temperature of red blood cell suspension was increased from 0 or 22 degrees C to 37 degrees C, the addition of 1 microM lysolecithin resulted in reduction of haemolysis and relative stabilization of the membrane as compared to that observed in lysolecithin-free medium. This stabilizing effect was found first of all in calf red blood cells. This effect is hardly detectable in adult cattle red blood cells. ATP depletion resulted in reduction of the stabilizing effect of lysolecithin in calf red blood cells as well. In the presence of 10 microM lysolecithin elevation of the incubation temperature from 22 degrees C to 37 degrees C enhanced the haemolysis of calf red blood cells, while the haemolysis of adult cattle red blood cells was practically not affected. The present results indicate that lysolecithin sensitivity of red blood cells is remarkably different in new-born and adult animals.