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


CONCLUSIONS
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.
Ersoy
Betul
B
Department of Pediatrics, Division of Pediatric Endocrinology, Faculty of Medicine, Celal Bayar University, Manisa 45010, Turkey. betul.ersoy@bayar.edu.tr
Ozbilgin
Kemal
K
Kasirga
Erhun
E
Inan
Sevinc
S
Coskun
Senol
S
Tuglu
Ibrahim
I
D000818:Animals; D020397:Goblet Cells / Q000166:cytology; D013006:Growth Hormone / Q000378:metabolism*; D006706:Homeostasis; D019382:Human Growth Hormone / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis*; D007413:Intestinal Mucosa / Q000378:metabolism; D007421:Intestine, Small / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism; D008297:Male; D051381:Rats; D017208:Rats, Wistar
D018972:Insulin-Like Growth Factor Binding Protein 3; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone