THE a-GLOBULIN FRACTION OF THE SERUM OF NORMAL AND HYPOPHYSECTOMIZED RATS*

Previous experiments (l-3) have shown that following hypophysectomy the serum globulin concentration of dogs and rats increases and at the same time the serum albumin level falls. In the above studies serum albumins and globulins were separated by salt fractionation (4). With the aim of checking our earlier results and of obtaining more detailed information regarding the changes in serum protein after hypophysectomy, we have made electrophoretic as well as chemical analyses of the sera of intact and hypophysectomized rats. In agreement with the observations of Jameson and Alvarez-Tostado (5) we find but two electrophoretic globulin fractions (usually designated as @and -y-globulin) in the serum of normal rats. The third globulin component, usually designated as a-globulin and found in the sera of most species ((6-9); and others), is absent or, if present, occurs in very low concentration. After hypophysectomy, however, the a-globulin fraction appears along with the two other globulin components and is in part responsible for the postoperative increase in serum globulin level. Some of the quantitative electrophoretic and chemical data obtained from the sera of intact and hypophysectomized rats are reported in the present communication.