AIMTo examine the liver mechanism with which clenbuterol (CL) is explained how to affect growth metabolism.

METHODSThe technique of chronic poly catheter was used to study the effects of CL (0.8 mg/kg b w) on the hepatic flux of nitrogen, VFA and glucose in 4 sheep.

RESULTSThe urea-nitrogen flux in CL-treated period always was lower than that in control during 24 h. The average flux of urea-nitrogen in hepatic and portal vein were decreased by 16.86% (P < 0.01) and 15.51% (P < 0.05), respectively, compared with that of control. The peptide level in hepatic vein was decreased with the treatment of CL, average flux of peptide was decreased by 38.71% (P < 0.01). But the peptide level of portal vein in CL treatment period was similar to control. Moreover, VFA level in the portal vein was enhanced by CL, the average flux of acetate in portal vein was increased by 19.49% (P < 0.01). No difference of VFA level in hepatic vein was noted between CL-treated period and control. In addition, the glucose flux in hepatic vein was obviously increased with CL treatment, the average flux of glucose was increased by 25.96% (P < 0.01). And glucose flux in portal vein was also elevated during CL-treated period.

CONCLUSIONCL can affect growth metabolism of animal with increasing nitrogen deposition, improving absorption and utilization of VFA and enhancing glucose synthesis in sheep liver.