Modulation of immunoreactive epidermal growth factor levels in the submandibular gland, pancreas, liver, kidney and gastrointestinal tract of suckling rats by cortisone and tri-iodothyronine
| Autor: | R. P. Schaudies, D. Davis, J. Grimes, O. Koldovský |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Male
medicine.medical_specialty Endocrinology Diabetes and Metabolism Submandibular Gland Ileum Biology Kidney Jejunum Endocrinology Epidermal growth factor Internal medicine medicine Animals Pancreas Gastrointestinal tract Epidermal Growth Factor Stomach Rats Inbred Strains Submandibular gland Animals Suckling Rats Cortisone medicine.anatomical_structure Liver Duodenum Triiodothyronine Female Digestive System medicine.drug |
| Zdroj: | Journal of Endocrinology. 131:95-100 |
| ISSN: | 1479-6805 0022-0795 |
| DOI: | 10.1677/joe.0.1310095 |
| Popis: | Suckling rats exhibit age-dependent differences in epidermal growth factor (EGF) levels in several organs. The present studies evaluated the effects of two hormones known for their maturative effect on suckling rats, cortisone and tri-iodothyronine (T3), on immunoreactive EGF levels in specific organs. Suckling rats were administered cortisone (5 mg/100 g body weight per day) or T3 (50 μg/100 g body weight per day) on days 8, 9, 10 and 11 after birth, and killed on day 12. Submandibular glands, kidneys, pancreas, liver and gastrointestinal tract mucosa and lumen were assayed for immunoreactive EGF by a speciesspecific radioimmunoassay. Low levels of EGF in the submandibular glands were increased slightly by both T3 and cortisone treatment. Cortisone evoked a tenfold increase in EGF in the pancreas, but had no effect on levels in the kidney or liver. In contrast, T3 evoked a sixfold increase in the EGF level in the kidney, but had no effect on levels in the pancreas or liver. Hormonal administration had no effect on EGF levels in the stomach. Within the intestinal tract, cortisone had no effect on the luminal EGF content of the duodenum, jejunum or ileum, but caused a decrease in the midjejunum. T3 evoked a decrease in the luminal EGF content of the ileum. The effect of cortisone on mucosal EGF content varied between regions; an increase was seen in the duodenum with a decrease in the midjejunum and ileum. T3 administration resulted in a significant decrease in EGF only in the mucosa of the ileum. The EGF-degradative capacity of the luminal contents of the jejunum and ileum, as studied in vitro, were increased by treatment with both T3 and cortisone. However, no direct correlation was observed between alterations of the EGF content in the lumen or mucosa and the increased degradative capacity. We therefore conclude that modulation of EGF levels within the intestine cannot be explained exclusively by alterations in the degradation rates. The results indicate that both adrenal and thyroid glands may play an important role in the modulation of EGF levels in the developing rat. Journal of Endocrinology (1991) 131, 95–100 |
| Databáze: | OpenAIRE |
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