Nitric oxide synthesis by tracheal smooth muscle cells by a nitric oxide synthase-independent pathway.
نویسندگان
چکیده
Nitric oxide (NO) is known to be synthesized from l-arginine in a reaction catalyzed by NO synthase. Liver cytochrome P-450 enzymes also catalyze the oxidative cleavage of CN bonds of compounds containing a -C(NH2)NOH function, producing NO in vitro. The present study was designed to investigate whether there was evidence of a similar pathway for the production of NO in tracheal smooth muscle cells. Formamidoxime (10-2 to 10-4 M), a compound containing -C(NH2)NOH, relaxed carbachol-contracted tracheal rings and increased intracellular cGMP in cultured tracheal smooth muscle cells, whereasl-arginine had no such effect. NO was detectable in the medium containing cultured tracheal smooth muscle cells when incubated with formamidoxime. Ethoxyresorufin (10-7 to 10-4 M), an alternate cytochrome P-450 substrate, inhibited formamidoxime-induced cGMP accumulation as well as tracheal ring relaxation in cultured tracheal smooth muscle cells. The NO synthase inhibitors N ω-nitro-l-arginine (10-3 M) and N G-monomethyl-l-arginine (10-3 M) had no effect on formamidoxime-induced cGMP accumulation. These results suggest that NO can be synthesized from formamidoxime in tracheal smooth muscle cells, presumably by a reaction catalyzed by cytochrome P-450.
منابع مشابه
EXPRESSION OF INDUCIBLE NITRIC OXIDE SYNTHASE GENE (iNOS) STIMULATED BY HYDROGEN PEROXIDE IN HUMAN ENDOTHELIAL CELLS
Inducible nitric oxide synthase (iNOS) gene expresses a calcium calmudolin-independent enzyme which can catalyse NO production from L-arginine. The induction of iNOS activity has been demonstrated in a wide variety of cell types under stimulation with cytokines and lipopoly saccharide (LPS). Previous studies indicated that all nitric oxide synthases (NOS) activated in human umbilical vein endot...
متن کاملInduction of nitric oxide synthase gene by interleukin in vascular smooth muscle cells.
To elucidate whether cytokines induce nitric oxide synthase in vascular smooth muscle cells, we studied the effects of human recombinant interleukin-1 beta on the synthesis and release of nitric oxide in cultured rat vascular smooth muscle cells by measurement of NO2-/NO3- levels. Furthermore, we performed Northern blot analysis using subcloned polymerase chain reaction products as probes for c...
متن کاملNitric Oxide Functions; an Emphasis on its Diversity in Infectious Diseases
Nitric oxide is a short-lived mediator, which can be induced in a variety of cell types and produces many physiologic and metabolic changes in target cells. It is important in many biological functions and generated from L-arginine by the enzyme nitric oxide synthase. Nitric oxide conveys a variety of messages between cells, including signals for vasorelaxation, neurotransmission and cytotoxici...
متن کاملEffects of Aspirin-Like Drugs on Nitric Oxide Synthesis in Rat Vascular Smooth Muscle
The purpose of this study was to investigate the effects of aspirin-like drugs on nitric oxide (NO) synthesis in rat vascular smooth muscle cells (VSMCs). We measured the accumulation of nitrite, a stable oxidation product of NO, and the expression of inducible NO synthase (iNOS) mRNA and protein in rat cultured VSMCs. Sodium salicylate, aspirin, and indomethacin dose-dependently enhanced nitri...
متن کاملEffects of aspirin-like drugs on nitric oxide synthesis in rat vascular smooth muscle cells.
The purpose of this study was to investigate the effects of aspirin-like drugs on nitric oxide (NO) synthesis in rat vascular smooth muscle cells (VSMCs). We measured the accumulation of nitrite, a stable oxidation product of NO, and the expression of inducible NO synthase (iNOS) mRNA and protein in rat cultured VSMCs. Sodium salicylate, aspirin, and indomethacin dose-dependently enhanced nitri...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- American journal of physiology. Lung cellular and molecular physiology
دوره 275 5 شماره
صفحات -
تاریخ انتشار 1998