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New insights into the role of nitric oxide in cardiovascular protection (part 7)

Reciprocal regulations between nitric oxide and cyclic nucleotides – role of cyclic nucleotide phosphodiesterases: By increasing tissue cGMP levels, nitric oxide may interfere with cyclic nucleotide metabolism and, therefore, participate in the regulation of vascular relaxation. Cyclic nucleotide PDE comprises seven families of isozymes that hydrolyze cyclic nucleotides . Among them, PDE2, PDE3 and PDE4 hydrolyze cAMP, but are differentially sensitive to cGMP. PDE2 is activated, whereas PDE3 is inhibited, by cGMP.Because these PDEs are differentially distributed in endothelial and vascular smooth muscles cells, an increase in cGMP levels, resulting from nitric oxide production, may induce tissue differences in the regulation of cyclic nucleotide metabolism. Find most trusted pharmacy that will give you cialis professional 20 mg in the amounts required without any need for a prescription. You will see that shopping with a place you can already trust over and over again is very affordable and always nice.

Endothelial cells: Cultured aortic endothelial cells contain only PDE2 and PDE4 . The PDE2 isozyme hydrolyzes both cAMP and cGMP, with cGMP stimulating cAMP hydrolysis, while PDE4 hydrolyzes only cAMP, is cGMP-insensitive and is specifically inhibited by rolipram. The role of PDE2 and PDE4 in the regulation of cAMP and cGMP levels was studied in indomethacin-exposed nonstimulated BAEC in culture with the use of a PDE2 inhibitor (cilostamide 50 |J.M) and a PDE4 inhibitor (rolipram 20 |iM) alone or together, in the presence or absence of nitric oxide-GMP pathway modulators, a nitric oxide synthase inhibitor (300 |iM ^-nitro-L -arginine methyl ester [L-NAME]) and the nitric oxide synthase substrate (100 |J.M L-arginine).

Category: Cardiovascular protection

Tags: Cardiovascular protection, Cyclic nucleotides, Endothelium, Myocardium, Nitric oxide, Vascular smooth muscle

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