GKT137831 and hydrogen peroxide increase the release of 6-nitrodopamine from the human umbilical artery, rat-isolated right atrium, and rat-isolated vas deferens.

Introduction: The human umbilical artery (HUA), rat-isolated right atrium, and rat-isolated vas deferens present a basal release of 6-nitrodopamine (6-ND). The basal release of 6-ND from these tissues was significantly decreased (but not abolished) when the tissues were pre-incubated with Nω-nitro-L-arginine methyl ester (L-NAME). Methods: In this study, the effect of the pharmacological modulation of the redox environment on the basal release of 6-ND was investigated. The basal release of 6-ND was measured using Liquid chromatography with tandem mass spectrometry (LC-MS/MS). Results and Discussion: Pre-incubation (30 min) of the tissues with GKT137831 (1 µM) caused a significant increase in the basal release of 6-ND from all tissues. In the HUA, pre-incubation with diphenyleneiodonium (DPI) (100 µM) also caused significant increases in the basal release of 6-ND. Preincubation of the HUA with hydrogen peroxide (H2O2) (100 µM) increased 6-ND basal release, whereas pre-incubation with catalase (1,000 U/mL) significantly decreased it. Pre-incubation of the HUA with superoxide dismutase (SOD) (250 U/mL; 30 min) also significantly increased the basal release of 6-ND. Preincubation of the HUA with either allopurinol (100 µM) or uric acid (1 mM) had no effect on the basal release of 6-ND. Pre-treatment of the HUA with L-NAME (100 µM) prevented the increase in the basal release of 6-ND induced by GKT137831, diphenyleneiodonium, and H2O2. The results obtained indicate a major role of endogenous H2O2 and peroxidases as modulators of 6- ND biosynthesis/release and a lack of peroxynitrite contribution.

A 2-week treatment with 5-azacytidine improved the hypercontractility state in prostate from obese mice: Role of the nitric oxide-cyclic guanosine monophosphate signalling pathway.

Benign prostatic hyperplasia (BPH) is characterised by increases in prostate volume and contraction. Downregulation of the nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) signalling pathway contributes to prostate dysfunctions. Previous studies in cancer cells or vessels have shown that the epigenetic mechanisms control the gene and protein expression of the enzymes involved in the production of NO and cGMP. This study is aimed to evaluate the effect of a 2-week treatment of 5-azacytidine (5-AZA), a DNA-methyltransferase inhibitor, in the prostate function of mice fed with a high-fat diet. Functional, histological, biochemical and molecular assays were carried out. Obese mice presented greater prostate weight, α-actin expression and contractile response induced by the α-1adrenoceptors agonist. The relaxation induced by the NO-donor and the protein expression of endothelial nitric oxide synthase (eNOS) and soluble guanylate cyclase (sGC) were significantly decreased in the prostate of obese mice. The treatment with 5-AZA reverted the higher expression of α-actin, reduced the hypercontractility state of the prostate and increased the expression of eNOS and sGC and intraprostatic levels of cGMP. When prostates from obese mice treated with 5-AZA were incubated in vitro with inhibitors of the NOS or sGC, the inhibitory effect of 5-AZA was reverted, therefore, showing the involvement of NO and cGMP. In conclusion, our study paves the way to develop or repurpose therapies that recover the expression of eNOS and sGC and, hence, to improve prostate function in BPH.

Inhibition of multidrug resistance proteins by MK571 restored the erectile function in obese mice through cGMP accumulation.

BACKGROUND: Intracellular levels of cyclic nucleotides can also be controlled by the action of multidrug resistance protein types 4 (MRP4) and 5 (MRP5). To date, no studies evaluated the role of their inhibition in an animal model of erectile dysfunction (ED). OBJECTIVES: To evaluate the effect of a 2-week treatment with MK571, an inhibitor of the efflux of cyclic nucleotides in the ED of obese mice. MATERIALS AND METHODS: Mice were divided in three groups: (i) lean, (ii) obese, and (iii) obese + MK571. The corpus cavernosum (CC) were isolated, and concentration-response curves to acetylcholine (ACh), sodium nitroprusside (SNP), and tadalafil in addition to electrical field stimulation (EFS) were carried out in phenylephrine pre-contracted tissues. Expression of ABCC4 and ABCC5, intracellular levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), the protein levels for pVASPSer157 and pVASPSer239 , and the intracavernous pressure (ICP) were also determined. The intracellular and extracellular (supernatant) ratios in CC from obese and lean stimulated with a cGMP-increasing substance (BAY 58-2667) in the absence and presence of MK571 (20 µM, 30 min) were also assessed. RESULTS: The treatment with MK571 completely reversed the lower relaxing responses induced by EFS, ACh, SNP, and tadalafil observed in obese mice CC in comparison with untreated obese mice. Cyclic GMP and p-VASPSer239 expression were significantly reduced in CC from obese groups. MK571 promoted a sixfold increase in cGMP without interfering in the protein expression of p-VASPSer239 . Neither the cAMP levels nor p-VASPSer157 were altered in MK571-treated animals. The ICP was ∼50% lower in obese than in the lean mice; however, the treatment with MK571 fully reversed this response. Expressions of ABCC4 and ABCC5 were not different between groups. The intra/extracellular ratio of cGMP was similar in CC from obese and lean mice stimulated with BAY 58-2667. CONCLUSIONS: The MRPs inhibition by MK571 favored the accumulation of cGMP in the smooth muscle cells, thus improving the smooth muscle relaxation and the erectile function in obese mice.

Endothelial and vascular smooth muscle dysfunction in hypertension.

The development of essential hypertension involves several factors. Vascular dysfunction, characterized by endothelial dysfunction, low-grade inflammation and structural remodeling, plays an important role in the initiation and maintenance of essential hypertension. Although the mechanistic pathways by which essential hypertension develops are poorly understood, several pharmacological classes available on the clinical settings improve blood pressure by interfering in the cardiac output and/or vascular function. This review is divided in two major sections. The first section depicts the major molecular pathways as renin angiotensin aldosterone system (RAAS), endothelin, nitric oxide signalling pathway and oxidative stress in the development of vascular dysfunction. The second section describes the role of some pharmacological classes such as i) RAAS inhibitors, ii) dual angiotensin receptor-neprilysin inhibitors, iii) endothelin-1 receptor antagonists, iv) soluble guanylate cyclase modulators, v) phosphodiesterase type 5 inhibitors and vi) sodium-glucose cotransporter 2 inhibitors in the context of hypertension. Some classes are already approved in the treatment of hypertension, but others are not yet approved. However, due to their potential benefits these classes were included.

6-NitroDopamine is an endogenous modulator of rat heart chronotropism.

6-Nitrodopamine (6-ND) is released by rat vas deferens and exerts a potent contractile response that is antagonized by tricyclic antidepressants and α1-, ß1- and ß1/ß2-adrenoceptor antagonists. The release of 6-ND, noradrenaline, adrenaline and dopamine from rat isolated right atria was assessed by tandem mass spectrometry. The effects of the catecholamines were evaluated in both rat isolated right atria and in anaesthetized rats. 6-ND was the major catecholamine released from the isolated atria and the release was significantly reduced in nitric oxide synthase inhibitor L-NAME pre-treated atria or in atria obtained from L-NAME chronically treated animals, but unaffected by tetrodotoxin. 6-ND (1 pM) significantly increased the atrial frequency, being 100 times more potent than noradrenaline and adrenaline. Selective ß1-blockers reduced the atrial frequency only at concentrations that prevented the increases in atrial frequency induced by 6-ND 1pM. Conversely, ß1-blockade did not affect dopamine (10 nM), noradrenaline (100 pM) or adrenaline (100 pM) effect. The reductions in atrial frequency induced by the ß1-adrenoceptor antagonists were absent in L-NAME pre-treated atria and in atria obtained from chronic L-NAME-treated animals. Tetrodotoxin did not prevent the reduction in atrial frequency induced by L-NAME or by ß1-blockers treated preparations. In anaesthetized rats, at 1 pmol/kg, only 6-ND caused a significant increase in heart rate. Inhibition of 6-ND synthesis by chronic L-NAME treatment reduced both atrial frequency and heart rate. The results indicate that 6-ND is a major modulator of rat heart chronotropism and the reduction in heart rate caused by ß1-blockers are due to selective blockade of 6-ND receptor.

The Role of Periprostatic Adipose Tissue on Prostate Function in Vascular-Related Disorders.

The lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH) are highly prevalent worldwide. Clinical and experimental data suggest that the incidence of LUTS-BPH is higher in patients with vascular-related disorders such as in pelvic ischemia, obesity and diabetes as well as in the ageing population. Obesity is an important risk factor that predisposes to glucose intolerance, insulin resistance, dyslipidemia, type 2 diabetes mellitus and cardiovascular disorders. Prospective studies showed that obese men are more likely to develop LUTS-BPH than non-obese men. Yet, men with greater waist circumferences were also at a greater risk of increased prostate volume and prostate-specific antigen than men with lower waist circumference. BPH is characterized by an enlarged prostate and increased smooth muscle tone, thus causing urinary symptoms. Data from experimental studies showed a significant increase in prostate and epididymal adipose tissue weight of obese mice when compared with lean mice. Adipose tissues that are in direct contact with specific organs have gained attention due to their potential paracrine role. The prostate gland is surrounded by periprostatic adipose tissue (PPAT), which is believed to play a paracrine role by releasing growth factors, pro-inflammatory, pro-oxidant, contractile and anti-contractile substances that interfere in prostate reactivity and growth. Therefore, this review is divided into two main parts, one focusing on the role of adipokines in the context of obesity that can lead to LUTS/BPH and the second part focusing on the mediators released from PPAT and the possible pathways that may interfere in the prostate microenvironment.

Faith, Family, and Social Networks: Effective Strategies for Recruiting Brazilian Immigrants in Maternal and Child Health Research.

Participation of racial/ethnic minority and immigrant populations in research studies is essential to understand and address health disparities. Nonetheless, these populations are often underrepresented in research because of limited participation that may be due to barriers to participation such as fear and mistrust of research, lack of or limited access to healthcare and social services, time and employment constraints, participation-associated costs (e.g., travel costs), language barriers, undocumented status, and cultural differences. Brazilians comprise a rapidly growing immigrant population group in the United States (US), and there is a need to identify and understand factors affecting the health status of Brazilian immigrants that are amenable to intervention. Therefore, this paper presents effective strategies and lessons learned from outreach and recruiting Brazilian immigrants living in the US to enroll in maternal and child health research studies. Using a data recruitment log, we collected quantitative and qualitative data on recruitment strategies that were employed to recruit pregnant women and parents into six health research studies. Direct recruitment strategies included personal contacts of research staff and recruiting partners, and on-site, in-person outreach and recruitment at faith- and community-based events (e.g., meeting participants after church services, at faith-based community events), and private and social events (e.g., household parties) conducted by bilingual, bicultural research assistants who were members of the priority population. We also used snowball sampling as a recruitment strategy by asking enrolled participants to share information about our studies and encourage their family and friends to participate. Indirect recruitment methods included posting flyers at local businesses, social service agencies, faith-based and healthcare organizations, and posting announcements on social media (Facebook). Direct recruitment methods in combination with snowball sampling were the most successful strategies for recruiting Brazilian immigrant parents, while social media was an effective indirect method for recruiting first-time pregnant women. In addition, analyses of qualitative data found that research staff's understanding of the sociocultural context of the target population combined with the use of linguistically and culturally sensitive recruitment strategies tailored to meet the needs of Brazilian immigrants was important for overcoming barriers to participation and facilitating successful recruitment and enrollment of participants. Study findings provide information on a suite of effective strategies and lessons learned for reaching, recruiting, and enrolling Brazilian immigrants in maternal and child health research. Future studies should continue to purposefully collect information on recruitment strategies and disseminate the findings, which will be instrumental in researchers' efforts to increase participation of ethnic minority and immigrant populations such as Brazilians in health research.

Guanosine, a guanine-based nucleoside relaxed isolated corpus cavernosum from mice through cGMP accumulation.

In corpus cavernosum (CC), guanosine triphosphate (GTP) is converted into cyclic guanosine monophosphate (cGMP) to induce erection. The action of cGMP is terminated by phosphodiesterases and efflux transporters, which pump cGMP out of the cell. The nucleotides, GTP, and cGMP were detected in the extracellular space, and their hydrolysis lead to the formation of intermediate products, among them guanosine. Therefore, our study aims to pharmacologically characterize the effect of guanosine in isolated CC from mice. The penis was isolated and functional and biochemical analyses were carried out. The guanine-based nucleotides GTP, guanosine diphosphate, guanosine monophosphate, and cGMP relaxed mice corpus cavernosum, but the relaxation (90.7 ± 12.5%) induced by guanosine (0.000001-1 mM) was greater than that of the nucleotides (~ 45%, P < 0.05). Guanosine-induced relaxation was not altered in the presence of adenosine type 2A and 2B receptor antagonists. No augment was observed in the intracellular levels of cyclic adenosine monophosphate in tissues stimulated with guanosine. Inhibitors of nitric oxide synthase (L-NAME, 100 µM) and soluble guanylate cyclase (ODQ, 10 µM) produced a significant reduction in guanosine-induced relaxation in all concentrations studied, while in the presence of tadalafil (300 nM), a significant increase was observed. Pre-incubation of guanosine (100 µM) produced a 6.6-leftward shift in tadalafil-induced relaxation. The intracellular levels of cGMP were greater when CC was stimulated with guanosine. Inhibitors of ecto-nucleotidases and xanthine oxidase did not interfere in the response induced by guanosine. In conclusion, our study shows that guanosine relaxes mice CC and opens the possibility to test its role in models of erectile dysfunction.

Magnetic fields: biomass potential of Spirulina sp. for food supplement.

This study evaluated the influence of the magnetic field on the chemical composition of Spirulina sp. LEB 18 and its digestibility and protein solubility. The highest protein digestibility of biomass was obtained at 30 °C and with 2.5 g L-1 NaNO3 (78.4%) in the medium, and the highest solubility was found in the cultivated biomass exposed to 60 mT, 30 °C and 2.5 g L-1 NaNO3 (89%, pH 6). MF application did not modify the protein concentration of biomass, but reduced the carbohydrate concentration by 69.1%, showing that the biomass obtained in the culture submitted to MF may be used as an ingredient in the development of protein supplements.

Autonomic dysregulation at multiple sites is implicated in age-associated underactive bladder in female mice.

AIMS: To evaluate the functional and molecular alterations of contractile and relaxant machinery in the bladder and urethra that lead to the underactive bladder (UAB) in old female mice. METHODS: Female young (3-months) and old (18-months) C57BL/6 mice were used. Urodynamic was assessed in awake and anaesthetized mice. Electrical-field stimulation (EFS) and concentration-response curves to contractile and relaxing agents in isolated bladders and urethras were performed. Messenger RNA (mRNA) expressions of muscarinic, adrenergic, and transient receptor potential vanilloid-4 (TRPV4), and of the enzymes tyrosine hydroxylase and neuronal nitric oxide synthase (nNOS) were determined. Bladder cyclic adenosine monophosphate (cAMP) levels were measured. RESULTS: Cystometry in old mice showed incapacity to produce bladder emptying. On filter paper, old mice showed reduced urinary spots. Compared to the young group, bladder contractions induced by EFS and carbachol were lower in old mice. The ß3 -adrenoceptor agonist mirabegron promoted higher bladder relaxation and elevation of cAMP levels in old mice. In old mice urethras, the α1a -adrenoceptor agonist phenylephrine produced higher contractions, but no differences were found for the NO donor sodium nitroprusside-induced relaxations. In old mice, increased mRNA expressions of ß3 - and α1a -adrenoceptors in bladder and urethra were found, respectively, whereas the muscarinic M2 and M3 receptors and ß2 -adrenoceptors did not change between groups. Reduced mRNA expressions of tyrosine hydroxylase and nNOS were found in old mouse urethras. Additionally, TRPV4 expression was reduced in bladder urothelium from old mice. CONCLUSION: Age-associated mouse UAB is the result of autonomic dysfunction at multiple levels leading to the less sensitive and overrelaxed bladder, along with urethral hypercontractility.

Inhibition of Multidrug Resistance Proteins by MK 571 Enhances Bladder, Prostate, and Urethra Relaxation through cAMP or cGMP Accumulation.

The biologic effect of cAMP and cGMP is terminated by phosphodiesterases and multidrug resistance proteins MRP4 and MRP5, which pump cyclic nucleotides out of the cell. Therefore, this study aimed to characterize the role of MRP inhibitor, MK 571 (3-[[[3-[(1E)-2-(7-chloro-2-quinolinyl)ethenyl]phenyl][[3-(dimethylamino)-3-oxopropyl]thio]methyl]thio]propanoic acid), in the bladder, prostate, and urethra of male mice by means of functional assays, protein expression, and cyclic nucleotide quantification. The cumulative addition of MK 571 (1-30 µM) produced only small relaxation responses (approximately 25%) in all studied tissues. In the bladder, isoprenaline/fenoterol and forskolin concentration-dependently relaxed and MK 571 (20 µM) increased the maximal response values by 37% and 24%, respectively. When MK 571 was coincubated with fenoterol or forskolin, intracellular levels of cAMP and protein expression of phospho-vasodilator-stimulated phosphoprotein (p-VASP) Ser157 were significantly greater compared with bladders stimulated with fenoterol or forskolin alone. In the prostate and urethra, sodium nitroprusside concentration-dependently relaxed and MK 571 (20 µM) significantly increased relaxation responses by 70% and 56%, respectively, accompanied by greater intracellular levels of cGMP and protein expression of p-VASP Ser239 in the prostate. Tadalafil and BAY 41-2272 (5-cyclopropyl-2-[1-[(2-fluorophenyl)methyl]-1H-pyrazolo[3,4-b]pyridin-3-yl]-4-pyrimidinamine) also relaxed the prostate and urethra, respectively, and MK 571 markedly enhanced this response. The stable analog of cGMP (8-Br-cGMP) induced concentration-dependent relaxation responses in the prostate and urethra, and MK 571 significantly increased the relaxation response. In conclusion, to our knowledge, this is the first study to show that efflux transporters are physiologically active in the bladder, prostate, and urethra to control intracellular levels of cAMP or cGMP.

Access and utilization of healthcare services in Massachusetts, United States: a qualitative study of the perspectives and experiences of Brazilian-born immigrant women.

BACKGROUND: Understanding immigrants' interactions with the United States (US) healthcare system will likely make it possible to meet their healthcare needs and improve their quality of life in the US. Although challenges to accessing and utilizing healthcare in the US have been identified, there is little information specific to Brazilian-born immigrants' experiences. Brazilians comprise a fast-growing immigrant population group in the US. The purpose of this study was to explore Brazilian immigrant women's perspectives and experiences with healthcare services in the US to gain insights into factors amenable to interventions that may contribute to disparities in access to and utilization of services. METHODS: Five focus groups were conducted from April to May in 2015 using a purposeful sampling of Brazilian-born immigrant women living in Massachusetts, US. RESULTS: Thirty-five women participated in this study. Although participants expressed their overall satisfaction with the US healthcare system, they noted several barriers to care, including sociocultural differences in delivery of care and communication barriers, including inconsistent quality of interpreting services. CONCLUSIONS: This study provides new information on the experiences and challenges faced by Brazilian immigrant women in accessing and utilizing healthcare services in the US and points out opportunities for improving services and the overall health of this immigrant population. Addressing noted sociocultural differences and communication barriers including inconsistent quality of hospital's interpreting services might enhance Brazilian-born immigrants' experiences with the healthcare system.

[International academic mobility program in nursing experience report]. / Programa de mobilidade acadêmica internacional em enfermagem: relato de experiência.

An experience of studying abroad or of academic exchange, really adds value to the professional and personal development of exchange students. This report aims to describe a student's experience in an international academic mobility program. It was developed from 2008 to 2009 in Brazil and Spain. The experiences, observations and activities of the student were emphasized believing that the training of students and researchers is not only restricted to the university and the students' home country, and that it is important to have possibilities of new experiences and differentiated knowledge. The conclusion is that this opportunity promoted a profound effect on psychological, cultural social and scientific development of the exchange student.