Sulfhydryl-depleting agents, but not deferoxamine, modulate EDRF action in cultured pulmonary arterial cells
| Autor: | Nandor Marczin, U. S. Ryan, John D. Catravas |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Pulmonary and Respiratory Medicine
Physiology Vasodilator Agents Vasodilation Deferoxamine Pulmonary Artery Pharmacology Biology Nitric Oxide Muscle Smooth Vascular chemistry.chemical_compound Physiology (medical) medicine Animals Cyclic GMP Cells Cultured Deferoxamine mesylate Sulfhydryl Reagents Endothelium-derived relaxing factor Biological activity Cell Biology Nitro Compounds Endothelial stem cell Biochemistry chemistry Endothelium Vascular Sodium nitroprusside Intracellular medicine.drug |
| Zdroj: | American Journal of Physiology-Lung Cellular and Molecular Physiology. 265:L220-L227 |
| ISSN: | 1522-1504 1040-0605 |
| DOI: | 10.1152/ajplung.1993.265.3.l220 |
| Popis: | The potential role of intracellular sulfhydryls and iron on the biological activity of endothelium-derived relaxing factor (EDRF) released basally from bovine pulmonary arterial endothelial (BPAE) cells was investigated in a cultured cell bioassay system, by measuring N omega-nitro-L-arginine-sensitive guanosine 3',5'-cyclic monophosphate (cGMP) accumulation in rabbit pulmonary arterial smooth muscle (SM) cells. The role of sulfhydryls in the biosynthesis of EDRF was studied by selectively exposing the endothelial cells to thiol-depleting agents. Both N-ethylmaleimide (NEM) and maleic acid diethyl ester (DEM) inhibited EDRF-induced cGMP accumulation in a dose-dependent manner. To study the requirement of SM thiols in the metabolism of EDRF to a stimulator of cGMP formation, SM were selectively exposed to NEM and DEM before bioassay with control, untreated BPAE. DEM and NEM inhibited cGMP formation in response to EDRF by 30 and 68%, respectively. The requirement of SM sulfhydryls was further investigated in the stimulation of SM cGMP accumulation elicited by nitrosothiols [S-nitroso-L-cysteine, S-nitroso-mercaptoproprionic acid, and sodium nitroprusside (SNP)]. NEM pretreatment of SM cells abolished cGMP responses to all vasodilators; DEM did not affect the nitrosothiol responses but reduced by 30% the cGMP accumulation to SNP. The role of iron in the endothelial synthesis of EDRF was assessed by chelating endothelial low-molecular-weight iron compounds. Exposure of BPAE to deferoxamine mesylate had no effect on cGMP accumulation in SM, suggesting that deferoxamine-available iron is not necessary for the endothelial stimulation of SM cGMP formation.(ABSTRACT TRUNCATED AT 250 WORDS) |
| Databáze: | OpenAIRE |
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