[Nature of the change in insulin receptors on the lymphocytes in a tumor-bearing organism].

Rat spleen lymphocytes were shown to bind insulin in vitro. This reaction which comes to saturation depends on both pH and temperature. In competition experiments two types of binding sites differing in their ability to bind insulin were revealed. In Zajdela hepatoma-bearing rats both Kass values and lymphocytes ability to bind insulin were increased, whereas in hepatoma G-27 bearing rats the number of receptors on lymphocytes was drastically decreased. On the second day of Zajdela hepatoma growth the number of receptors on lymphocyte was decreased 1.5-fold, then it was increased reaching the maximum up to fifth day with 5-fold augmentation. The changes in insulin-binding ability of lymphocytes were found to correlate with insulin-binding of the same rat liver plasma membranes. This finding indicates that the character of changes in insulin-binding ability is similar in various tissues of tumor-bearing rats.