Stimulation of phosphatidylinositol turnover by acetylcholine, angiotensin II and ACTH in bovine adrenal fasciculata cells
| Autor: | Arthur J. Hadjian, Martine Culty, Edmond M. Chambaz |
|---|---|
| Rok vydání: | 1984 |
| Předmět: |
Atropine
endocrine system medicine.medical_specialty Angiotensin receptor Hydrocortisone Phosphatidic Acids Stimulation Biology Phosphatidylinositols chemistry.chemical_compound Adrenocorticotropic Hormone Internal medicine Muscarinic acetylcholine receptor medicine Animals Phosphatidylinositol Molecular Biology Angiotensin II Cell Biology Phosphatidic acid Acetylcholine Endocrinology Mechanism of action chemistry Adrenal Cortex Cattle medicine.symptom medicine.drug |
| Zdroj: | Biochimica et biophysica acta. 804(4) |
| ISSN: | 0006-3002 |
| Popis: | The effect of acetylcholine, angiotensin II and adrenocorticotropin (ACTH) on phosphatidylinositol (PI) metabolism was examined using bovine adrenocortical fasciculata cell suspensions. The three agents, which acutely stimulate glucocorticoid production by these cells, were all able to increase [32P]Pi incorporation into cellular PI. However, whereas the relative steroidogenic potency (at maximally active concentrations) was ACTH greater than or equal to angiotensin II greater than acetylcholine, the effect on PI labeling was in the order angiotensin II greater than acetylcholine greater than ACTH. The dose-response curves for steroidogenesis and that for PI labeling were superimposable in the case of angiotensin II (ED50 = 1 X 10(-8) M) and of acetylcholine (ED50 = 5 X 10(-7) M), while the two responses were dissociated under graded ACTH challenge. Both steroidogenic response and increased PI labeling elicited by angiotensin II and acetylcholine were respectively inhibited by (Sar1-Ala8)-angiotensin II and muscarinic antagonists. Time-course study showed that in the case of angiotensin II and acetylcholine, the sequence of events was: increased phosphatidic acid labeling, increased PI labeling, activated steroidogenesis. By sharp contrast, under ACTH stimulation, increased steroidogenesis was detected well before activation of PI metabolism. These data suggest that in bovine adrenocortical fasciculata cell, steroidogenesis may be activated by two different pathways. The first one would act mainly through cyclic AMP-dependent intracellular events and is usually accepted in the mechanism of action of ACTH. The other, cyclic AMP-independent pathway, as in the case of angiotensin II and acetylcholine actions, may involve phospholipid-mediated intracellular processes. |
| Databáze: | OpenAIRE |
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