Abstract
AIM: To evaluate the effects of growth hormone (GH) on the residual small intestine of rats with short bowel syndrome (SBS), including adaptive hyperplasia and absorption of glucose and amino acids.
METHODS: Forty Sprague-Dawley (SD) male rats with more than 85% small intestine resected were equally divided into five groups randomly: H-GH group (high dose at 7.5 IU/kg per day), M-GH group (moderate dose at 3.75 IU/kg per day), L-GH group (low dose at 1.88 IU/kg per day), SBS group and sham operation group. From the second to the 15th day after operation, all the GH-managed groups were treated by sc injection twice a day, while SBS group and sham group were managed with same volume normal saline for injection. All samples were gained by laparotomy under anesthesia at the 16th day after operation.
RESULTS: Weight loss of rats in H-GH group (36±4.4 g), which was the least among the four groups except sham group, was significantly less than that in SBS group (94±10.0 g) (P < 0.05). But preoperative body weight of rats in the four groups except sham group was not retrieved. Among all groups there was no significant difference in the length of jejunum and ileum, as well as no significant difference in the morphological variables of colon. Mucosal height of jejunum and ileum was greater in H-GH group and M-GH group (997±65.9 m, 752±79.3 m and 974±67.6 m, 788±75.1 m respectively) than those in SBS group (776±61.0 m, 664±64.0 m) (P < 0.05). Similarly, intestinal wall width of jejunum and ileum was also thicker in H-GH group and M-GH group (1142±65.4 m, 884±91.2 m and 1 145±78.7 m, 895±95.6 m respectively) than those in SBS group (848±194.7 m, 776±57.5 m) (P < 0.05). But mucosal height and intestinal wall width of jejunum and ileum in H-GH group were not significantly greater than those in M-GH group. Blood insulinlike growth factor 1 (IGF-1) concentration and PCNA index of liver did not differ among the five groups. No significant differences of blood glucose and amino acids concentrations were detected after nutritional administration among the five groups.
CONCLUSION: Treatment of SBS with GH only slows body weight decrease rather than promotes body weight gain by the support of enteral nutrition. GH enhances adaptive mucosal hyperplasia after massive resection of small intestine, while its enhanced effect does not parallel its dose increase. Because of GH resistance resulted from the SBS-induced malnutrition,elevation of blood IGF-1 is impaired and absorpton of glucose and amino acids is not enhanced.
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