Serum and tissue dopamine-β-hydroxylase activity in hypophysectomized rats
| Autor: | Kjell Fuxe, Lewis S. Freedman, Menek Goldstein, T. Hökfelt, Mark Roffman |
|---|---|
| Rok vydání: | 1973 |
| Předmět: |
Male
medicine.medical_specialty Sympathetic Nervous System Time Factors Hypophysectomy medicine.medical_treatment Fluorescent Antibody Technique Dopamine beta-Hydroxylase Biology Immunofluorescence Dexamethasone Cell size Adrenocorticotropic Hormone Ganglia Spinal Internal medicine Adrenal Glands medicine Dopamine β hydroxylase Animals Mesenteric arteries Pharmacology Sheep medicine.diagnostic_test Histocytochemistry Body Weight Organ Size Mesenteric Arteries Rats Endocrinology medicine.anatomical_structure Adrenal Medulla Pituitary Gland Cervical ganglia Rabbits Adrenal medulla medicine.drug |
| Zdroj: | European Journal of Pharmacology. 24:366-374 |
| ISSN: | 0014-2999 |
| Popis: | Serum dopamine-β-hydroxylase activity is increased in rats after hypophysectomy. The maximal increase in serum hydroxylase activity occurs 2–4 weeks after hypophysectomy and reaches approximately 150% above the control values. ACTH, but not dexamethasone, causes the activity to decrease. Dopamine-β-hydroxylase activity is markedly reduced in the mesenteric arteries and in the cervical ganglia of rats after pituitary ablation. The activity in the mesenteric arteries can be partially restored by treatment with ACTH but not by treatment with dexamethasone. The immunofluorescence studies reveal a reduction in the cell size and a decrease in the dopamine-β-hydroxylase protein concentration in the adrenal medulla of hypophysectomized rats (6 weeks after hypophysectomy). These 2 effects are most likely responsible for the decrease in dopamine-β-hydroxylase activity in the adrenals of hypophysectomized animals. Treatment of rats with ACTH after hypophysectomy resulted in an increase in specific dopamine-β-hydroxylase immunofluorescence in the adrenal medulla while treatment with dexamethasone had no effect on the intensity of immunofluorescence. However, treatment with dexamethasone 1–2 weeks after pituitary ablation partially restores the dopamine-β-hydroxylase activity in the adrenal medulla. The immunohistofluorescence and the biochemical data indicate that the ACTH effect on the dopamine-β-hydroxylase activity is not entirely mediated via the adrenal glucocorticoids. |
| Databáze: | OpenAIRE |
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