We have characterized the markedly elevated cyclic AMP and cyclic GMP phosphodiesterase activities of a recently isolated S49 mouse lymphoma mutant, termed K30a, and compared both activities to enzyme activities in the parental wild type S49 cell. cAMP phosphodiesterase activity in K30a appears to be slightly larger than the major wild type CAMP-hydrolyzing enzyme, in sucrose gradient sedimenta...

INTRODUCTION Benign prostate hyperplasia and erectile dysfunction affect a significant subset of men. BPH and ED may have the same promoting conditions and are the strong predicting risk factors to each other. A significant number of these patients are bothered by lower urinary tract symptoms (LUTS). Direct correlation of age, sexual dysfunction and LUTS severity has been well documented. Many ...

1. A spectrophotometric assay of 2':3'-cyclic nucleotide 3'-phosphodiesterase (EC 3.1.4.37) based on the use of an acid-base indicator and a buffer having identical PKa values is described. The assay is sinmple and rapid; it was particularly convenient for monitoring the enzyme activity at vat :ous stages of purification. 2. Several proteinases were examined for their ability to solubilize 2':3...

The extracellular levels of cyclic AMP (cAMP), cAMP phosphodiesterase activity, and adenylate cyclase activity were measured at various intervals during growth and morphogenesis of Arthrobacter crystallopoietes. There was a significant rise in the extracellular cAMP level at the onset of stationary phase, and this rise coincided with a decrease in intracellular cAMP. The phosphodiesterase activ...

Despite demonstrated clinical efficacy of sildenafil for the temporary treatment of erectile dysfunction, the possibility that sildenafil used long-term durably augments erectile ability remains unclear. We investigated whether continuous long-term administration of sildenafil at clinically relevant levels to aged rats "primes" the penis for improved erectile ability and involves nitric oxide (...

OBJECTIVES We investigated the influence of sildenafil on cardiac contractility and diastolic relaxation and examined the distribution of phosphodiesterase-5 in the hearts of hypertensive rats that were treated with by NG-nitro-L-arginine methyl ester (L-NAME). METHODS Male Wistar rats were treated with L-NAME and/or sildenafil for eight weeks. The Langendorff method was used to examine the e...

UNLABELLED Phosphodiesterase type 5 Inhibitors, such as sildenafil, vardenafil and tadalafil have been increasingly used today and some of the users have developed sudden sensorineural hearing loss. OBJECTIVE To present two patients with sudden deafness developed after an occasional use of the drug and review studies on the use of phosphodiesterase type 5 inhibitors and sudden hearing loss. ...