ISSN:
1432-0428
Keywords:
Keywords Cyclic AMP
;
nitric oxide
;
cyclic GMP
;
nitrite
;
diabetic neuropathy
;
sodium potassium ATPase
;
protein kinase A
;
human neuroblastoma cells
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary We investigated the relation between cyclic AMP (cAMP) and nitric oxide (NO) production, as well as the effect of NO on Na+ , K+-ATPase activity in the human neuroblastoma cell line SH-SY5Y. Two cAMP agonists, dibutyryl cAMP (DBC) and beraprost sodium (BPS), increased cAMP accumulation and NO production in a time and dose dependent manner at 50 mmol/l glucose. On the other hand, cellular sorbitol and myo-inositol contents and protein kinase C activity were not altered by DBC or BPS. A specific protein kinase A inhibitor, H-89, suppressed increases in nitrite/nitrate and cyclic GMP (cGMP) and protein kinase A activity stimulated by DBC or BPS. This finding suggests that cAMP stimulates NO production by activating protein kinase A via a pathway different from the sorbitol-myo-inositol-protein kinase C pathway. We observed that an NO donor, sodium nitroprusside, and an NO agonist, L-arginine, enhanced ouabain sensitive Na+, K+-ATPase activity at 50 mmol/l glucose. We also found that a nitric oxide synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME), inhibited Na+, K+-ATPase activity at 5 mmol/l glucose, and partially suppressed the enzyme activity stimulated by DBC or BPS. The results of this study suggest that cAMP regulates protein kinase A activity, NO production and ouabain sensitive Na+, K+-ATPase activity in a cascade fashion. The results also suggest that protein kinase A at least partially regulates Na+, K+-ATPase activity without mediation by NO in SH-SY5Y cells. We speculate that cAMP and NO are two important regulatory factors in the pathogenesis of diabetic neuropathy. [Diabetologia (1998) 41: 1451–1458]
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s001250051091
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