The liver exhibits a remarkable regenerative capacity after major resection provided it is normal. It is commonly
assumed that a normal liver tolerates 70-80% resection safely. On the other hand, the capacity for regeneration after partial hepatectomy in chronic liver disease such as produced by schistosomiasis mansoni, is still unknown. The aim of this work is to assess DNA, thymidine kinase activity and liver function tests after partial hepatectomy in normal hamsters compared to those infected with schistosoma mansoni, this is to show the effect of schistosomal infestation on the regenerative ability of the liver. In the bilharzial groups there was a significant increase in the liver DNA level (P<0.005). In the nonbilharzial group there was a highly significant increase in the liver DNA level (P<0.005). In the bilharzial groups there was a significant increase in the liver thymidine kinase activity (P<0.005), in the non-bilharzial group there was a highly significant increase in the liver thymidine kinase activity (P<0.005). In the bilharzial group there was a marked rise in the serum enzyme during the first three days after partial hepatectomy (P<0.005) and still high even after three weeks. In the non-bilharzial group there was a significant rise in the AST observed during the first three days after surgery (P<0.005) and returned to the pre-operative mean value by the second post-operative week. !n the bilharzial group, total proteins showed a significant decrease (P< 0.05) in relation to the pre-operative baseline value, and still after three weeks post-hepatectomy (P<0.05) didn't recover to the preoperative mean value. In the bilharzial group there was a significant rise in serum total bilirubin during the first three days after partial hepatectomy (P<0.005) which continued up to the third week post hepatectomy. In the non-bilharzial group there was a significant increase observed up to three days after the operation ( P < 0.005 ) and started to drop after the first week posthepatectomy. The bilharzial group showed a significant rise in Serum Alkaline Phosphatase (P< 0.05) during the first three days after the operation and returned to the baseline value after the first week after the operation. The nonbilharzial group didn't show any changes throughout the whole periods after the operation.