title: Dehydroepiandrosterone sulfate inhibition of catecholamine secretion from bovine adrenal chromaffin cells.
abstract: Dehydroepiandrosterone sulfate (DHEAS) dose-dependently inhibited [3H]norepinephrine (NE) secretion and the corresponding [Ca2+]i rise induced by the nicotinic receptor agonist 1,1-dimethyl-4-phenylpoperazimium (DMPP) in bovine chromaffin cells. DHEAS at 10 microM, the physiological concentration in human serum, significantly inhibited both the release of [3H]NE and the rise of [Ca2+]i induced by DMPP in chromaffin cells. DHEAS also inhibited the [3H]NE release induced by the Na+ channel activator veratridine. However, DHEAS did not affect either the [3H]NE release, or the corresponding [Ca2+]i rise induced by high K+. Moreover, DHEAS suppressed the [Na+]i rise induced by either DMPP or high K+ as monitored by the fluorescence 340/380 ratio of SBFI loaded chromaffin cells. Our results suggest that the inhibitory effects of DHEAS on secretion mainly occur at nicotinic receptors as well as at the voltage-dependent Na+ channels.
authors.affiliation: Department of Microbiology, Soochow University, Shihlin, Taipei, Taiwan.
authors.forename: P S
authors.initials: PS
authors.lastname: Liu
authors.forename: M K
authors.initials: MK
authors.lastname: Lin
authors.forename: H L
authors.initials: HL
authors.lastname: Hsieh
mesh_terms: D000311:Adrenal Glands / Q000166:cytology* / Q000378:metabolism; D000818:Animals; D001572:Benzofurans; D002118:Calcium / Q000032:analysis; D002395:Catecholamines / Q000037:antagonists & inhibitors / Q000378:metabolism; D002417:Cattle; D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D002838:Chromaffin System / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D003600:Cytosol / Q000737:chemistry; D019314:Dehydroepiandrosterone Sulfate / Q000494:pharmacology*; D004246:Dimethylphenylpiperazinium Iodide / Q000494:pharmacology; D004988:Ethers, Cyclic; D005456:Fluorescent Dyes; D016257:Fura-2; D015640:Ion Channel Gating / Q000502:physiology; D018722:Nicotinic Agonists / Q000494:pharmacology; D009638:Norepinephrine / Q000037:antagonists & inhibitors* / Q000378:metabolism; D012964:Sodium / Q000032:analysis; D014316:Tritium / Q000378:metabolism
chemical_list: D001572:Benzofurans; D002395:Catecholamines; D004988:Ethers, Cyclic; D005456:Fluorescent Dyes; D018722:Nicotinic Agonists; D014316:Tritium; C061665:sodium-binding benzofuran isophthalate; D004246:Dimethylphenylpiperazinium Iodide; D019314:Dehydroepiandrosterone Sulfate; D012964:Sodium; D002118:Calcium; D016257:Fura-2; D009638:Norepinephrine