Abstract
Variations in the strength of the capillary walls have long been observed, perhaps because this property is easily measured, as compared with the general obscure nature of these minute vessels. | Scarborough was quick to recognize (1940) that, although changes in capillary resistance followed a deficiency of vitamin P, this is not the only circumstance causing similar changes in the capillaries.(1) Following this line of thought he noted that capillary resistance in humans was significantly increased following transfusion with blood or plasma.(2) He next studied capillary resistance in humans following the injection of 4 cc. blood into any tissue and found the capillary resistance uniformly elevated.(3) Following this observation a study of twenty-three post-operative eases revealed a definite rise in the capillary resistance in all cases.(4) Again, emphasis is placed on the lack of physiological explanation of this phenomenon. Ungar (1944) at this time observed a definite uniform, rise in the capillary resistance in various animals following trauma. He also found that the sera of the traumatized animals when injected into normal animals caused a simultaneous change in bleeding time and capillary resistance, suggesting a common circulating factor acting on the capillary wall.(5) Robson (1949) lists as an incidental finding the increase in capillary resistance in thirty-nine post-operative case.(6)