| Objective Our previous studies have shown that glycolysis in RBC is depressed entirely in patients undergoing major surgery, while pentose phosphorate pathway(PPP) is activated at the same time. We have known that polyol pathway as the third pathway in RBC can be activated underwent thoracic operations. We still do not know how polyol pathway changes during stress response to abdominal surgical injury. In the present study, we investigated the changes of aldose reductase activity in patients undergoing abdominal surgery, whether the change of glucose metabolism is related to oxidative stress, and what are the effects of anesthetics and different anesthetic techniques on glucose metabolism and oxidative stress.Methods 60 ASA physical status I and II patients, undergoing elective abdominal surgery were randomly allocated to three groups with 20 cases each. Anesthesia was induced with midazolam 0.1 mg/kg, propofol 1-1.5 mg/kg and vecuronium 0.1 mg/kg, and maintained with propofol 60-100 ug/kg/min infusion ( group I ) or 1.5-2.0 MAC isoflurane inhalation ( group II ) , or combined 1.0-1.5 MAC isoflurane inhalation with epidural block ( group III) . The venous samples were collected to measure the plasma levels ofglucose, malonadialdehyde ( MDA ) , gltathione ( GSH ) and nitric oxide ( NO ) , superoxide dismutase ( SOD ) , glutathione peroxidase( GSH-Px ), catalase( CAT Activities and phosphofructokinase( PFK ), glucose-6-phasphate dehydrogenase( G-6PD ), aldose reductase( AR ) activities in RBC at 30min before anesthesia ( T1 ) , 90 min after incision ( T2 ) , 60 min after surgery ( T3 ) and on the 1st, 2nd postoperative days ( T4, T5 ) .Results (1) The levels of plasma glucose were increased significantly at 90min after incision and kept at a high level till on the 1st postoperative day in all three groups(P<0.05 or P<0.01) as compared with those before anesthesia, the level of plasma glucose in group II on the 1st postoperative day was higher than that in group UK P<0.05 ), plasma glucose levels nearly returned to the baseline on the 2nd postoperative day in all groups. (2) Plasma MDA level was increased significantly on the 1st postoperative day in group II as compared with the value before anesthesia(P<0.05), but not in group I and group III ( P>.05 ) . (3)Plasma GSH level was decreased markedly on the 1st postoperative day in group II as compared with that before anesthesia (P<0.05), and was not significantly changed in group I and group III ( P>0.05 ) ; at that time, the change of GSH in group III was less than that in group II (P<0.05). (4)Compared with the values before anesthesia, SOD activity changed slightly in all three groups(P>0.05) . GSH-Px activity was increased in different exertent during and after operation, but no significant difference occurred among three groups(P<0.05). CAT activity was increased significantly on the 1st postoperative day in group II and higher than that in group III ( P<0.05 ) , which was not significant in group I and group III( P>0.05 ) . (5)Compared with the preanesthetic value, the levels of plasma NO in all three groups were decreased in different exertent during and after operation, which was significantly on the 1st to 2ndpostoperaive day in group I (P<0.01). Plasma NO was significantly lower in group II than that in group III on the 1st postoperative day (P<0.01). (6) The activity of PFK was decreased significantly and the activities of G-6PD and AR in RBC were increased markedly on the 1st postoperative day in group I and II (P<0.05 or P<0.01) , but not in group III ( P>.05 ) . The exertent of changes in PFK, G-6PD and AR activities in group III was less than that in group II on the 1st postoperative day (P<0.05).Conclusions (1) In patients undergoing abdominal surgery, polyol pathway activates, while plasma glucose is increased, with a depression in glycolysis of RBC and activation of the pentose phosphorate pathway. Oxidative stress markers change at the same time. These changes suggest that oxidative stress occurrs and the change of glu...
|
PDF Full Text Request