Absence of Correlation between Haemorrhagic Lymph and Prolonged Bleeding Time During Experimental Thrombocytopenia

Abstract

The level of circulating blood platelets below which a prolonged bleeding time can be found, is somewhat dependent on the age of the platelets at hand. However, when studying the appearance of red cells in the lymph of animals during experimental thrombocytopenia, no such critical level could be found at all (I. Aursncs, Scand. J. Haemat. 13, 184-195). Thus very low levels of circulating blood platelets with markedly prolonged bleeding time can be seen in animals with no red cell leakage to their lymph.Those observations have now been somewhat extended by observing the same two-pmeters in rabbits soon after their production of blood platelets has been completely stopped by a more heavy dose of whole body irradiation. Abnormal leakage of red cells to lymph (drained from the ears which had been shielded during the irradiation) the often occurred at levels of 100-400,000 platelets per μl, whereas the bleeding times in the same animals were usually not significantly prolonged until the platelet concentration fell below 50,000 per μl blood.An explanation for the two described phenomena would be that the vascular supportive effect and the haemostatic effect of blood platelets are dependent on two different mechanisms.