CHANGES OF NITRIC-OXIDE SYNTHASE ACTIVITY AND FREE METHYLARGININES CONTENTS IN REGENERATING RAT-LIVER AFTER PARTIAL-HEPATECTOMY

In the present study, liver regeneration rate (%) was increased up to 70% 3 days after partial hepatectomy (PH). Nitric oxide synthase (NOS) activity in liver tissue as well as serum nitrite/nitrate content had no timed response, revealing no significant difference between sham-o perated and partially hepatectomized rat liver. Contents of free methy larginines in liver tissue were increased biphasically in a time-depen dent manner after PH. However, those in serum did not exhibit the same patterns as in liver. Taken together, the results suggest that N-G-mo nomethyl-L-arginine (MMA) and N-G, N-G-dimethylarginine (DMA) play a r ole in inhibiting nitric oxide (NO) synthesis in regenerating rat live r because the increase of their contents was synchronized with NOS exp ression.