[Establishment of a new gastric bypass animal-model with GK rats]

To establish a new gastric bypass animal-model with Goto-Kakizaki rats whose different parts of the small intestine were bypassed while stomach was not bypassed.

Forty male 3-month-old GK rats were randomly divided into 4 groups: group I (sham operation), group II (duodenum bypassed), group III (jejunum bypassed), group IV (ileum bypassed). Fasting plasma glucose was measured before operation and the 1st, 4th,and 8th week after operation in all the rats, the body weight of all the rats were measured simultaneously.

The survival rate of operation for the rats was 95%. Two rats in group IV (died on the first day after operation. The mean fasting plasma glucose concentration of the rats in group II, III, IV (declined obviously 4 weeks after gastric bypass [group II (12.02+/-1.97) vs (6.36+/-0.50) mmol/L, group III (13.42+/-1.66) vs (5.96+/-0.53) mmol/L, group IV (14.32+/-2.82) vs (5.18+/-0.49) mmol/L, all P <0.01], but there were no significant differences among the gastric bypassed groups. The weight of rats in group I, II, III (increased obviously after gastric bypass [group I (253.6+/-9.37) vs (367.0+/-23.70) g, group II (268.2+/-7.95) vs (384.8+/-16.12) g, group III (253.0+/-6.20) vs (323.0+/-16.40) g, all P <0.05] except the rats in group IV ([(262.0+/-13.47) vs(185.8+/-11.56) g].

The mean fasting plasma glucose concentration of the GK rats decreases obviously after gastric bypass through different parts of small intestine. The fasting plasma glucose concentration is not associated with the length of small intestine and body weight.