[The change of glucagon-like peptide-1 and its effect on blood glucose metabolism after major surgery].

Objective: To investigate the change of glucagon-like peptide-1(GLP-1) and its effect on blood glucose metabolism after major surgery.

Methods: Eleven patients, who had undergone major surgical procedures in our Department of General Surgery, were studied on the day before surgery, the first, third, and fifth day after surgery. Then, 42 rats were allocated randomly into three groups. The rats in control, which had not undergone any operation, received an intravenous glucose load (0.5 g/kg glucose + normal saline). The rats in operated group, which had undergone about 65% liver resection, received a same glucose load on the first, third,and fifth postoperative day. And the rats in GLP-1 group, which had undergone same hepatectomy, received a same glucose load with GLP-1 (0.3 nmol/kg) on the first, third,and fifth day after surgery. All rats would be killed by abdominal aorta exsanguinated in five minutes after drugs were infused of which the bloods were collected for determination of glucose (glucose oxidase), insulin, glucagon, and GLP-1 (radioimmunoassays) at each time-point.

Results: There was an increasing postoperative plasma concentration of glucose, insulin, and glucagon on the first day (P < 0.01), but the plasma GLP-1 was just elevated on the third day (P < 0.05). Then, the plasma glucose concentration was significantly lowered after GLP-1 given to rats undergoing hepatectomy (P < 0.001), which might reach the glucose range in controls. Lowering of blood glucose was achieved by a significant rise of insulin secretion (P < 0.001) and a suppression of glucagon secretion (P < 0.05).

Conclusion: As far as can be concluded on basis of our data from patients and rats, GLP-1 can be used to reduce the plasma glucose concentrations when it is in stress status after major surgery.