Effect of growth hormone on small intestinal homeostasis relation to cellular mediators IGF-I and IGFBP-3 - PubMed (original) (raw)

Effect of growth hormone on small intestinal homeostasis relation to cellular mediators IGF-I and IGFBP-3

Betul Ersoy et al. World J Gastroenterol. 2009.

Abstract

Aim: To evaluate the effects of growth hormone (GH) on the histology of small intestines which might be related to the role of insulin like growth factor (IGF)-I, IGF-binding protein 3 (IGFBP-3) and its receptors.

Methods: Twelve week-old adult male Wistar albino rats were divided into two groups. The study group (n = 10), received recombinant human growth hormone (rGH) at a dose of 2 mg/kg per day subcutaneously for 14 d and the control group (n = 10) received physiologic serum. Paraffin sections of jejunum were stained with periodic acid shift (PAS) and hematoxylin and eosin (HE) for light microscopy. They were also examined for IGF-I, IGFBP-3 and IGF-receptor immunoreactivities. Staining intensity was graded semi-quantitatively using the HSCORE.

Results: Goblet cells and the cells in crypt epithelia were significantly increased in the study group compared to that of the control group. We have demonstrated an increase of IGF-I and IGFBP-3 immunoreactivities in surface epithelium of the small intestine by GH application. IGF-I receptor immunoreactivities of crypt, villous columnar cells, enteroendocrine cells and muscularis mucosae were also more strongly positive in the study group compared to those of in the control group.

Conclusion: These findings confirm the important trophic and protective role of GH in the homeostasis of the small intestine. The trophic effect is mediated by an increase in IGF-I synthesis in the small intestine, but the protective effect is not related to IGF-I.

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Figures

Figure 1

Figure 1

Photomicrograph of the tunica mucosa (M) and muscularis mucosa (MM) of the small intestine in the GH-administered group. Villous hypertrophy and increased goblet cells were seen in the small intestine. PAS, × 100 (Original magnification).

Figure 2

Figure 2

Morphometric criteria to determine the effects of growth hormone on small intestine. VH: The height of villus; LP: Lamina Propria; SM: Submucosa; ME: Muscularis externa; ET: Thickness of epithelium; CE: Crypt epithelial cell; GS: The size of goblet cell; GN: The number of goblet cells per villus. Height of the villi, epithelial thickness, and crypt epithelial cell number rats given GH were significantly increased (P < 0.01). The size and the number of goblet cells were also significantly increased (P < 0.05).

Figure 3

Figure 3

Like growth factor (IGF)-R immunoreactivity pattern in small intestines of the rats in the study group given growth hormone (A) and control group (B) by using the immuno-peroxidase technique. While weak to moderate IGF-R immunostaining was observed in the epithelial cells of the small intestines in the control group, an increase in the immunostaining was seen in the study group. Note the strong immunoreactivity in the epithelial component and the moderately immunostained smooth muscle of the muscularis mucosa. Goblet cells display little or no immunoreactivity, in contrast to the dense immunoreaction in columnar cells of the study group. × 100 (Original magnifications).

Figure 4

Figure 4

Immunoreactivity of IGF-I was seen in the small intestine of the control group (A) and the study group (B) by using an immunofluorescence technique. Increased immunoreactivity was seen in the study group. × 200 (Original magnifications).

Figure 5

Figure 5

Immunoreactivity of IGF-binding protein 3 (IGFBP-3) was seen in the small intestines by using an immunofluorescence technique in the control group (A) and the study group (B). Increased immunoreactivity was seen in the study group. × 200 (Original magnifications).

Figure 6

Figure 6

IGFBP-3 and IGF-I immunoreactivities in rat small intestine epithelium in the control and the study groups using the indirect immunofluorescence method. (Weak immunostaining: +; Moderate immunostaining: ++; Strong immunostaining: +++). In rats that were given growth hormone, there was a statistically significant increase in the immunoreactivities of IGF-I.

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