Regeneration of splenic remnants after partial splenectomy in rats

Splenic regeneration in the rat was measured after removal of 25, 50, or 75% of the spleen, 50% of the spleen with autotransplantation of the excised portion, and splenectomy with autotransplantation of 50% of the spleen. Splenic growth in rats undergoing sham splenectomies served as a control. Splenic mass at 6 weeks and 4 months after surgery was directly related to the remnant size. “Normalized” spleen weights (measured as grams of splenic tissue per 100 grams of rat weight) after 25, 50, and 75% splenectomy were 57, 41, and 38% of controls at 6 weeks, and 77, 71, and 44% of controls at 4 months. All differences were significant at P < 0.03 except those between 50 and 75% splenectomy at 6 weeks, and between 25 and 50% splenectomy at 4 months. A comparison of autotransplanted splenic mass after total splenectomy with that after 50% splenectomy (0.042 ± 0.005 and 0.025 ± 0.004, respectively, at 6 weeks) demonstrated that an intact subtotal spleen inhibited significantly regeneration of the autotransplanted spleen. The effect of autotransplanted splenic tissue on regeneration of a splenic remnant was little to none at 4 months.