The role of lead in the reduction of the erythrocyte sedimentation rate by hyaluronidase.

It has been recorded that the increased erythrocyte sedimentation rate (ESR) of some pathological blood specimens, especially from patients with rheumatic fever, was decreased or abolished by incubation with certain preparations of hyaluronidase (1, 2). This effect was shown to be due to changes produced on the erythrocytes and not on the plasma (2) ; the erythrocytes were changed to spherocytes and so failed to form the rouleaux necessary for rapid sedimentation.’ The action on erythrocytes was considered to be enzymatic in nature (2), since it was dependent on time and temperature. However, the supposed enzyme was not identical with hyaluronidase, since the effect on the ESR did not parallel the hydrolyzing power of hyaluronidase on hyaluronic acid.1 The preparations of hyaluronidase, which were all made from ram or bull testes by ammonium sulfate and lead acetate fractionation (3), did not all have the same activity on the ESR. It had been found that these enzymes lost their activity on the ESR if they were treated with Na2S, rather than by dialysis, for the purpose of removing lead (4). The experiments reported here were performed to determine the nature of the action of hyaluronidase preparations on human erythrocytes. All the hyaluronidase preparations were made and supplied by Dr. Karl Meyer.