Purpose: Experimental studies have provided the basis for the evaluation of inhibitors of the phosphodiesterase type 5 (PDE5) in the treatment of lower urinary tract symptomatology (LUTS) secondary to benign prostatic hyperplasia (BPH). It has been speculated that the clinical efficacy of PDE5 inhibitors in patients with LUTS/BPH can be explained by their effects on the urinary bladder rather than on the prostate. Hence, the significance of the nitric oxide (NO)/cyclic GMP signaling in the control of the human prostate requires further clarification.
View Article and Find Full Text PDFIntroduction: Rho kinases (ROKs) cause calcium-independent modulation of smooth muscle contraction. A significant role for the RhoA/ROK pathway in mediating the contraction of the penile erectile tissue has been suggested. Moreover, it has been postulated that ROK activity might represent a key factor in the pathophysiology of erectile dysfunction.
View Article and Find Full Text PDFIntroduction: Phosphodiesterase (PDE) isoenzymes have been shown to play a role in the control of human male genital tissues. There are hints from basic research and clinical studies that PDE5 inhibitors may have the ability to retard the male ejaculatory response. While the expression of PDE isoenzymes in the human seminal vesicles (SVs) has been described, the distribution of cyclic adenosine monophosphate (AMP)- and cyclic guanosine monophosphate (GMP)-PDEs has not yet been investigated.
View Article and Find Full Text PDFIntroduction: The calcium-sensitizing Rho A/Rho kinase pathway has been suggested to play a role in the control of nongenital vascular smooth muscle. Rho-associated kinases (ROKs) cause calcium-independent modulation of smooth muscle contraction, and have been demonstrated in the bladder, prostate, and corpus cavernosum. Until now, it is not known whether ROKs and related proteins play a role in the control of vaginal blood flow.
View Article and Find Full Text PDFObjectives: To investigate the expression of isoforms of the cyclic AMP (cAMP)-dependent protein kinase (cAK) in the transition zone of the human prostate and the functional significance of the enzyme in the control of prostate smooth muscle.
Methods: Using Western blot analysis and immunohistochemistry, the expression and distribution in the prostate of cAKIalpha, cAKIbeta, cAKIIalpha, and cAKIIbeta in relation to alpha-actin and the phosphodiesterase PDE4 (types A and B) were investigated. The effects of the cAK inhibitor Rp-8-CPT-cAMPS on the reversion of the adrenergic tension of isolated prostate tissue induced by forskolin, rolipram, sodium nitroprusside (SNP), and tadalafil were examined by means of the organ bath technique.
Introduction: In contrast to research findings describing the localization of nitric oxide synthases (NOS), guanylyl cyclases, and cyclic adenosine monophosphate (cAMP)- and cyclic guanosine monophosphate (cGMP)-degrading phosphodiesterase isoenzymes in the human vagina, the distribution of proteins known as major targets for cyclic nucleotides has not yet been evaluated. cAMP- and cGMP-dependent protein kinases (cAK, cGKI) have been identified as important receptors for cyclic nucleotides downstream the signaling cascades.
Aim: To investigate, by means of immunohistochemistry, the expression of cAK and cGKI in relation to endothelial NOS (eNOS), vasoactive intestinal polypeptide (VIP), and protein gene product 9.
Introduction: The cyclic adenosine monophosphate-dependent protein kinase (cAK) is considered a key protein in the control of smooth muscle tone in the cardiovascular system. There is evidence that erectile dysfunction might be linked to systemic vascular disorders and arterial insufficiency, subsequently resulting in structural changes in the penile tissue. The expression and significance of cAK in human cavernous arteries (HCA) have not been evaluated.
View Article and Find Full Text PDFBackground: A role for the transient receptor potential (TRP) A1 ion channel in rat lower urinary tract (LUT) sensation and disease has been proposed, but in the human LUT no information on TRPA1 activity is available.
Objectives: To investigate the distribution of TRPA1 in the human urethra and to study the effect of TRPA1 agonists on isolated urethral strip preparations.
Design, Settings, And Participants: Urethral specimens were obtained preoperatively from 10 patients and were freshly prepared for Western blot, immunohistochemistry, and functional in vitro investigations.
Introduction: Besides the bioavailability of nitric oxide (NO), downstream guanine monophosphate (cGMP) effector proteins are also considered to play a significant role in penile vascular disease. In animal studies, a downregulation of the cGMP-dependent protein kinase-1 (cGKI) alpha isoform has been linked to erectile dysfunction and diabetes mellitus. So far, the expression of cGKI alpha and beta isoforms has not been evaluated in human penile erectile tissue.
View Article and Find Full Text PDFObjectives: To evaluate non-genomic effects of testosterone and dihydrotestosterone (DHT) on isolated human cavernosal arteries (HCA) and corpus cavernosum (HCC) using organ-bath studies and radio-immunoassays (RIA), as non-genomic effects of androgens are reported for vascular smooth musculature and there is evidence that the relaxant response involves a modulation of cyclic nucleotide tissue levels.
Materials And Methods: The relaxation induced by the cumulative addition of testosterone and DHT (0.01-10 microm) was studied using circular segments of HCA and strip preparations of HCC.
Objectives: Phosphodiesterase 5 (PDE5) inhibitors improve smooth muscle relaxation and therefore are considered for pharmacotherapy of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). Cyclic guanosine monophosphate (cGMP)-dependent protein kinase-1 (cGKI) has been identified as one of the downstream targets for cGMP. The aim of the present study was to evaluate, by means of immunohistochemistry and Western blot analysis, the expression and localization of cGKI isoforms in relation to smooth muscle alpha-actin and cGMP in the human prostate.
View Article and Find Full Text PDFObjectives: It has been well established that male erectile dysfunction is frequently associated with vascular diseases. The normal function of cavernous arteries is considered a prerequisite to maintain sufficient blood flow to the trabecular spaces in order to enable penile erection. Contractility of cavernous arteries is regulated by the peripheral autonomic nervous system and endogenous factors released from the endothelial cell layer.
View Article and Find Full Text PDFPurpose: We review our experience with endoscopic (totally) extraperitoneal radical prostatectomy (EERPE) as first line therapy for localized prostate cancer.
Materials And Methods: A total of 700 consecutive patients underwent EERPE. Mean patient age was 63.
Objectives: To evaluate the distribution of cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) phosphodiesterases (PDEs) in relation to nitric oxide synthase isoforms and vasoactive intestinal polypeptide (VIP) in specimens of the human vagina. Nitric oxide and VIP, mediating biologic signals through cGMP and cAMP, have been assumed to be involved in the control of vaginal smooth muscle.
Methods: Immunohistochemical techniques were applied to sectioned specimens of the human vaginal wall to evaluate the presence of the PDE isoenzymes 3, 4, 5, and 10 in relation to neuronal nitric oxide synthase (nNOS), endothelial NOS (eNOS), and VIP.
Nitric oxide (NO)/cyclic GMP (cGMP)-mediated mechanisms have a pivotal function in reducing the tone of the penile smooth musculature during normal erectile responses. The cyclic AMP (cAMP) signaling pathway is also involved in the adjustment of smooth muscle contractility, and suggestions for interactions between cGMP- and cAMP-mediated mechanisms have been presented. Using activators of the cGMP- or the cAMP-pathway, as well as inhibitors of protein kinase A (PKA; cAMP-dependent kinase) and protein kinase G (PKG; cGMP-dependent kinase), the present study was undertaken to further delineate the functional relation between these pathways in the penis.
View Article and Find Full Text PDFThe proliferation, recirculation and repertoire of gut-derived gamma/delta T cells were studied in pigs in vivo. Proliferating gamma/delta T cells (detected by BrdU labeling) are present in all intestinal compartments. In the gut lymph approximately 0.
View Article and Find Full Text PDFObjectives: The discovery of nitric oxide (NO) as one of the major effectors in penile erectile function has led to the development of various drugs which are able to elevate intracellular levels of cGMP. Recently, a novel class of NO donors have been developed, exemplified by S-nitroso-glutathione (GSNO) and S-nitroso-N-acetylcysteine-ethylester (SNACET), as well as compounds combining both phosphodiesterase inhibitory and NO donating activity, such as NCX 911 (sildenafil nitrate). In our study, we assessed the effects of GSNO, SNACET and NCX 911 on adrenergic tension and electrically induced relaxation of isolated human corpus cavernosum (HCC) and the in vitro formation of cGMP.
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