Detection of Growth-Stimulating Activity in the Proximal Small Intestine during Weaning in the Suckling Rat
| Autor: | T.N. Pham, E.G. Seidman, V.L. Grey, M.G. Poullain, C.L. Morin |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Aging
medicine.medical_specialty Adaptive change Weaning Biology Thymidine Kinase Internal medicine Intestine Small medicine Animals Growth Substances Lactase chemistry.chemical_classification Cell growth Rats Inbred Strains DNA beta-Galactosidase Small intestine Animals Suckling Rats Endocrinology Enzyme medicine.anatomical_structure chemistry Pediatrics Perinatology and Child Health Chromatography Gel Adaptation Cell Division Sucrase Developmental Biology |
| Zdroj: | Neonatology. 59:37-45 |
| ISSN: | 1661-7819 1661-7800 |
| DOI: | 10.1159/000243320 |
| Popis: | Adaptive changes in enzyme expression and cell proliferation occur in the small intestine of the suckling rat at the beginning of the 3rd postnatal week. This physiological adaptation can be modulated by factors including diet or glucocorticoids. We have previously described an intestinal growth-stimulating fraction derived from the remnant small bowel after resection and found that enteral nutrition is critical for its detection. In view of the similarity between the changes in cell proliferation that occur between 15 and 22 days postnatally and those immediately after resection, we sought to determine whether the small intestinal mucosa of the neonatal rat also contains a similar growth-stimulating fraction. Our results show that extracts of the proximal intestine prepared from 15-day-old rats do contain the growth-stimulating fraction. The activity was not detectable in maternal milk nor in the intestinal extract from 8-day-old rats. When the suckling rats were deprived of solid food, the activity was not detectable in the 15-day-old group. Gel filtration of the acidic extract on a G-25 Sephadex column revealed that the active component is made up of two molecular weight species (approximately 4,500 and 1,500 daltons) similar to that described in the proximal intestine of the postresectional model. These findings suggest that dietary factors may play a role in modulating the proliferative changes that occur at the time of weaning by way of the growth-stimulating fraction. |
| Databáze: | OpenAIRE |
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