Drugs to affect the smooth musculature of the human ureter - an update with integrated information from basic science to the use in medical expulsion therapy (MET).

Purpose: Urolithiasis and symptomatic ureterolithiasis represent diseases known to be on the increase in most westernized countries. The present article aims to give an overview on some drug principles assumed to target signalling systems involved in modulating ureter smooth muscle contractility and to present background to their potential use or prospects in ureter stone disease.

Methods: The article reviews drugs that have been evaluated over the last decades in vitro, in vivo and/or in clinical settings with regard to their properties to achieve spontaneous passage of (distal) ureteral stones and relieve colic pain.

Circulating and Urinary Concentrations of Malondialdehyde in Aging Humans in Health and Disease: Review and Discussion.

(1) Background: Malondialdehyde (MDA) is a major and stable product of oxidative stress. MDA circulates in the blood and is excreted in the urine in its free and conjugated forms, notably with L-lysine and L-serine. MDA is the most frequently measured biomarker of oxidative stress, namely lipid peroxidation.

Fibrotic Diseases of the Human Urinary and Genital Tract: Current Understanding and Potential Strategies for Treatment.

Fibrosis is a disease condition characterized by abnormalities of the extracellular matrix, such as accumulation of the transforming growth factor β, infiltration by myofibroblasts, deposition of collagen, and a generalized dysregulation of collagen maturation. It can severely impair the function of organs by replacing normal tissue with a highly collagenized matrix, thereby reducing the elasticity and compliance of tissues. Fibrotic diseases of the genitourinary tract present relevant problems in healthcare, and their principles of pathophysiology remain unclarified; hence, the armamentarium for prevention and treatment is limited.

Is cortisol an endogenous mediator of erectile dysfunction in the adult male?

Background: It has been speculated for decades whether there is a significance of the adrenal corticosteroid cortisol in the process of male sexual function, including the control of sexual arousal and penile erection. In order to investigate further the role of the adrenocorticotropic axis in the physiological process of penile erection, we aimed to determine the course of cortisol in the cavernous and systemic blood through different stages of sexual arousal in patients suffering from erectile dysfunction (ED) in comparison to a cohort of healthy males.

Methods: Fifty-four healthy adult males and 45 patients with ED were presented sexually explicit visual material in order to elicit tumescence and (in the healthy males) rigid erection.

Expression and distribution of the transient receptor potential cationic channel ankyrin 1 (TRPA1) in the human seminal vesicles.

Background And Aims: The transient receptor potential cationic channel ankyrin 1 (TRPA1), a channel protein permeable to most divalent cations, has been suggested to play a role in mechano-afferent/efferent signaling (including the release of neurotransmitters) in the human urinary tract (bladder, prostate, and urethra). To date, only a few studies have addressed the expression of this receptor in male and female reproductive tissues. The present study aimed to evaluate human seminal vesicles (SVs)  for the expression and localization of TRPA1.

[Metanephric adenoma, a benign variant of Wilms' tumour: case report of an extremely rare kidney tumour and literature survey].

Rare benign tumours of the kidney comprise a group of very different histogenetic entities. We report a case of a 53-year-old woman who underwent laparoscopic nephrectomy because of a renal mass. The diagnosis of a rare and benign metanephric adenoma was confirmed by histopathology.

An advanced method for the immunohistochemical detection of nitric oxide synthase (NOS) in the female genital tract.

The expression of nitric oxide synthase (NOS) in male and female urogenital tissues has been investigated by using conventional light microscopical immunoperoxidase staining. We present an improved immunohistochemical method for the specific and simultaneous detection of endothelial and neuronal NOS (eNOS/nNOS) in vaginal tissue. Specific antibodies have been used in combination with the tyramide signal amplification method.

Re-evaluation of the immunohistochemical distribution of isoforms of nitric oxide synthase in the human prostate: A light and electron microscopical study.

Up until today, there are still uncertainties regarding the occurrence of isoforms of the nitric oxide synthase (eNOS, nNOS) in the human prostate. While nNOS was exclusively seen in slender nerve fibres branching within the transition zone, eNOS was reported in glandular structures and also in small vessels interspersing the tissue. This study aimed to re-evaluate by means of light and electron microscopy (LM, EM), the distribution of eNOS and nNOS in the transition zone of the human prostate.

Expression of Phosphodiesterase (PDE) Isoenzymes in the Human Male and Female Urethra.

Purpose: Although it has been supposed that the NO/cyclic GMP system produces inhibitory signals to reduce the resistance of the bladder outlet and urethra during the micturition phase, little is known on the mechanisms controlling the function of urethral smooth muscle. The aim of the present study was to examine in the male and female urethra the expression of phosphodiesterase (PDE) isoenzymes, known as key proteins of the cyclic GMP/AMP signaling.

Methods: Urethral tissue was obtained from 4 female cadavers and 7 male patients (who had undergone gender reassignment surgery).

The Use of Vasoactive Drugs in the Treatment of Male Erectile Dysfunction: Current Concepts.

It is widely accepted that disorders of the male (uro)genital tract, such as erectile dysfunction (ED) and benign diseases of the prostate (lower urinary tract symptomatology or benign prostatic hyperplasia), can be approached therapeutically by influencing the function of both the vascular and non-vascular smooth muscle of the penile erectile tissue or the transition zone/periurethral region of the prostate, respectively. As a result of the discovery of nitric oxide (NO) and cyclic guanosine monophosphate (GMP) as central mediators of penile smooth muscle relaxation, the use of drugs known to increase the local production of NO and/or elevate the intracellular level of the second messenger cyclic GMP have attracted broad attention in the treatment of ED of various etiologies. Specifically, the introduction of vasoactive drugs, including orally active inhibitors of the cyclic GMP-specific phosphodiesterase (PDE) 5, has offered great advantage in the pharmacotherapy of ED and other diseases of the genitourinary tract.

Emerging drugs to target lower urinary tract symptomatology (LUTS)/benign prostatic hyperplasia (BPH): focus on the prostate.

Objectives: The benign prostatic syndrome, comprising lower urinary tract symptomatology secondary to benign prostatic hyperplasia/enlargement, represents a major health care issue in westernized countries. The pharmacological management involves alpha-adrenoceptor antagonists, intervention into the hormonal control of prostate growth using inhibitors of the enzyme 5-alpha-reductase, and stimulation of the nitric oxide/cyclic GMP pathway by tadalafil, an inhibitor of the phosphodiesterase type 5.

Methods: This review summarizes the achievements which have been made in the development of drug candidates assumed to offer opportunities as beneficial treatment options in the management of the benign prostatic syndrome.

Arginase enzymes in the human prostate: A molecular biological and immunohistochemical approach.

The nitric oxide (NO) pathway plays a role in maintaining the function of the prostate. An impairment in the activity of the NO system may have an impact in the manifestation of lower urinary tract symptomatology and benign prostatic hyperplasia. Arginase enzymes (Arg) counteract the generation of NO by depleting the intracellular pool of L-arginine, known to be the substrate of the NO synthases.

Development and validation of GC-MS methods for the comprehensive analysis of amino acids in plasma and urine and applications to the HELLP syndrome and pediatric kidney transplantation: evidence of altered methylation, transamidination, and arginase activity.

We developed and validated gas chromatography-mass spectrometry (GC-MS) methods for the simultaneous measurement of amino acids and their metabolites in 10-µL aliquots of human plasma and urine. De novo synthesized trideutero-methyl esters were used as internal standards. Plasma proteins were precipitated by acidified methanol and removed by centrifugation.

Course of transforming growth factor ß1 in the systemic and cavernous blood of healthy males through different penile conditions.

Studies on erectile dysfunction (ED) have revealed a relationship between smooth muscle atrophy and the accumulation of collagen in the corpus cavernosum (CC). Transforming growth factor ß1 (TGF ß1) is a cytokine which has been proposed to be involved in the fibrotic process in the CC. We aimed to evaluate the course of TGF ß1 in the systemic and cavernous blood of 17 healthy males through different phases of the sexual arousal response (exemplified by the penile conditions flaccidity, tumescence, rigidity and detumescence).

Is β-endorphin significant in the control of the male sexual response?

It has been assumed that β-endorphin, belonging to the family of opiodergic neuropeptides, might facilitate the inhibition of the male sexual response; however, its role in the control of the penile erectile tissue remains to be elucidated. This study aimed to evaluate in healthy men the course of β-endorphin in the systemic and cavernous blood through different stages of sexual arousal. Thirty-four (34) men were exposed to erotic stimuli to induce penile tumescence and rigidity.

Results, meta-analysis and a first evaluation of UR, the urinary nitrate-to-nitrite molar ratio, as a measure of nitrite reabsorption in experimental and clinical settings.

We recently found that renal carbonic anhydrase (CA) is involved in the reabsorption of inorganic nitrite (NO), an abundant reservoir of nitric oxide (NO) in tissues and cells. Impaired NO synthesis in the endothelium and decreased NO bioavailability in the circulation are considered major contributors to the development and progression of renal and cardiovascular diseases in different conditions including diabetes. Isolated human and bovine erythrocytic CAII and CAIV can convert nitrite to nitrous acid (HONO) and its anhydride NO which, in the presence of thiols (RSH), are further converted to S-nitrosothiols (RSNO) and NO.

-Nitroso--acetyl-L-cysteine ethyl ester (SNACET) and -acetyl-L-cysteine ethyl ester (NACET)-Cysteine-based drug candidates with unique pharmacological profiles for oral use as NO, HS and GSH suppliers and as antioxidants: Results and overview.

-Nitrosothiols or thionitrites with the general formula RSNO are formally composed of the nitrosyl cation (NO) and a thiolate (RS), the base of the corresponding acids RSH. The smallest -nitrosothiol is HSNO and derives from hydrogen sulfide (HSH, HS). The most common physiological -nitrosothiols are derived from the amino acid L-cysteine (CysSH).

Expression and distribution of phosphodiesterase isoenzymes in the human male urethra.

Objective: To investigate the expression and distribution of phosphodiesterase (PDE) isoenzymes PDE1A, PDE2A, PDE4A, PDE4B, and PDE5A in human urethral tissue.

Methods: Specimens of penile urethra were obtained from male subjects who had undergone male-to-female sex reassignment surgery. Using immunohistochemistry (immunofluorescence), the occurrence of PDE1A, PDE2A, PDE4A, PDE4B, and PDE5A, the neuronal nitric oxide synthase, calcitonin gene-related peptide, and vasoactive intestinal polypeptide was examined in urethral sections.

Phosphodiesterase isoenzymes in the human urethra: a molecular biology and functional study.

Experimental and clinical studies have suggested a role for phosphodiesterase (PDE) isoenzymes in the control of the human lower urinary tract. This study aimed to investigate the expression of PDE isoenzymes and the effects of PDE inhibitors (PDE-Is) in isolated human urethral smooth muscle (USM). The expression of messenger ribonucleic acid (mRNA) specifically encoding for PDE isoenzymes and isoforms (1A, 1B, 1C, 2A, 4A, 4B, 4C, 4D, 5A and 11A) was analyzed by means of reverse transcriptase polymerase chain reaction (RT-PCR).

Pharmacologic characterization of human male urethral smooth muscle: an in vitro approach.

Objective: To elucidate the functional responses of isolated human urethral smooth muscle to various agents known to exert smooth muscle contraction or relaxation.

Methods: Specimens of penile urethra were obtained from male patients who had undergone male-to-female gender reassignment surgery. Using the tissue bath technique, the contraction induced by increasing concentrations (1 nM-10 μM) of norepinephrine, phenylephrine, acetylcholine, carbachol, prostaglandin F2α, endothelin 1, angiotensin II, and oxytocin was measured.

The role of phosphodiesterases in bladder pathophysiology.

Nitric oxide and the cyclic nucleotide monophosphates cAMP and cGMP have a role in control of the micturition process and hence, are suggested to be involved in the pathophysiology of storage and voiding disorders. Phosphodiesterase enzymes (PDEs) hydrolyse cAMP and cGMP. Inhibition of PDEs increases cAMP and cGMP levels and relaxes urinary bladder smooth musculature.

Phosphodiesterase type 1, calcitonin gene-related peptide and vasoactive intestinal polypeptide are involved in the control of human vaginal arterial vessels.

Objective: The vagina makes a major contribution to the normal female sexual response cycle. An increase in vaginal blood flow is considered a key event in the mechanism of sexual arousal. Recent research has focused mainly on the cyclic GMP pathway and phosphodiesterase type 5 (PDE5, cyclic GMP specific PDE) in the control of vaginal vascular smooth muscle, whereas only little is known on the role of other key proteins and mediators of cyclic nucleotide mediated signaling in this process.

Phosphodiesterase type 5 (PDE5) is co-localized with key proteins of the nitric oxide/cyclic GMP signaling in the human prostate.

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.