Sarcoplasmic reticulum-associated cAMP phosphodiesterase activity was examined in microsomes prepared from the left ventricular myocardium of eight heart transplant recipients with end-stage idiopathic dilated cardiomyopathy and six unmatched organ donors with normal cardiac function. At cAMP concentrations < 1.0 MM, sarcoplasmic reticulum-associated cAMP phosphodiesterase activity was function...

Incubation of a hepatocyte particulate fraction with ATP and the isolated catalytic unit of cyclic AMP-dependent protein kinase (A-kinase) selectively activated the high-affinity 'dense-vesicle' cycle AMP phosphodiesterase. Such activation only occurred if the membranes had been pre-treated with Mg2+. Mg2+ pre-treatment appeared to function by stimulating endogenous phosphatases and did not aff...

The dependence of Protein Kinase A (PKA) activity on cAMP levels is an important facet of the dimorphic switch between budding and filamentous growth as well as for pathogenicity in some fungi. To better understand these processes in the pathogenic fungus Ustilago maydis, we characterized the structure and biochemical functions of two phosphodiesterase (PDE) genes. Phosphodiesterases are enzyme...

A pheochromocytoma was maintained in rats from the New England Deaconess Hospital by giving the rats s.c. injections of isolated tumor cells. The animals were sac rificed 3 to 4 weeks after transplantation, the tumors were excised, and purified tumor cells were prepared. Cyclic nucleotide phosphodiesterase of the purified tumor cells was characterized and compared with that of the adrenal medul...

OBJECTIVES To investigate the effect of phosphodiesterase type 5 inhibitor on urinary continence recovery after bilateral nerve-sparing radical prostatectomy. METHODS We analyzed data of 393 open bilateral nerve-sparing radical prostatectomies carried out between 2005 and 2010. Patients who recovered urinary continence within the first month after catheter removal (n = 52) were excluded. This...

In kidneys, stimulation of adenylyl cyclase causes egress of cAMP, conversion of cAMP to AMP by ecto-phosphodiesterase, and metabolism of AMP to adenosine by ecto-5'-nucleotidase. Although much is known about ecto-5'-nucleotidase, the renal ecto-phosphodiesterase remains uncharacterized. We administered cAMP (10 microM in the perfusate) to 12 different groups of perfused kidneys. AMP was measur...

During growth under conditions of phosphate limitation, suspension-cultured cells of tomato (Lycopersicon esculentum Mill.) secrete phosphodiesterase activity in a similar fashion to phosphate starvation-inducible ribonuclease (RNase LE), a cyclizing endoribonuclease that generates 2':3'-cyclic nucleoside monophosphates (NMP) as its major monomeric products (T. Nürnberger, S. Abel, W. Jost, K. ...

Sarcoplasmic reticulum-associated cAMP phosphodiesterase activity was examined in microsomes prepared from the left ventricular myocardium of eight heart transplant recipients with end-stage idiopathic dilated cardiomyopathy and six unmatched organ donors with normal cardiac function. At cAMP concentrations less than or equal to 1.0 microM, sarcoplasmic reticulum-associated cAMP phosphodiestera...

The inhibitor constants of several inhibitors for cyclic AMP- and cyclic GMP-phosphodiesterase from various organs are compared. The inhibitors were classical theophyline, papaverine, and some of newly developed inhibitors: an imidazolidinone compound, RO20-1724, and two phthalazinol compounds, EG 467 and EG 626. Among the inhibitors tested, papaverine and EG 626 were found to be the most poten...

A bovine brain protein recently discovered as an inhibitor of cyclic nucleotide phosphodiesterase has been partially purified and characterized. This inhibitor protein specifically counteracts the activation of phosphodiesterase by the Ca2+-dependent protein modulator. It shows no inhibitory activity against the Ca2+ -independent form of phosphodiesterase or the basal activity of the Ca2+-activ...