Effects of dehydration on blood viscosity and on distribution of plasma proteins in experimental macroglobulinaemia [24]

A GREAT variety of plasma cell tumours has been induced in mice and transplanted in successive generations of these animals^1,2. The tumours secrete large amounts of myeloma proteins and make it possible to examine various problems concerning the myelomas and dysproteinaemias. Usually, as the concentration of myeloma protein rises in the plasma of affected animals, the concentration of normal protein diminishes². A similar reduction of normal plasma proteins in humans with dysproteinaemias has been related either to decreased synthesis or to increased catabolism of normal protein fractions³. As yet, no data have appeared concerning the plasma concentrations of abnormal and normal proteins in experimental macroglobulinaemia. The plasma cell tumour designated MOPC-104E secretes large amounts of macroglobulin (IgM)⁴. Mice bearing this tumour resemble humans with macroglobulinaemia, in that both display an elevated blood viscosity which is related to the plasma concentration of IgM and modified by the haematocrit^5-7. It was of additional interest to determine whether these mice also resembled human macroglobulinaemics³ with respect to the relative intravascular concentrations of IgM and non-macroglobulin (non-IgM). This investigation examines this question. In addition, an attempt was made to alter the intravascular distribution of proteins by changing the osmotic balance of the animals through dehydration.