The paracrine control of vascular motion. A historical perspective

Perivascular Adipose Tissue and Vascular Smooth Muscle Tone: Friends or Foes?

Perivascular adipose tissue (PVAT) is a specialized type of adipose tissue that surrounds most mammalian blood vessels. PVAT is a metabolically active, endocrine organ capable of regulating blood vessel tone, endothelium function, vascular smooth muscle cell growth and proliferation, and contributing critically to cardiovascular disease onset and progression. In the context of vascular tone regulation, under physiological conditions, PVAT exerts a potent anticontractile effect by releasing a plethora of vasoactive substances, including NO, H₂S, H₂O₂, prostacyclin, palmitic acid methyl ester, angiotensin 1-7, adiponectin, leptin, and omentin. However, under certain pathophysiological conditions, PVAT exerts pro-contractile effects by decreasing the production of anticontractile and increasing that of pro-contractile factors, including superoxide anion, angiotensin II, catecholamines, prostaglandins, chemerin, resistin, and visfatin. The present review discusses the regulatory effect of PVAT on vascular tone and the factors involved. In this scenario, dissecting the precise role of PVAT is a prerequisite to the development of PVAT-targeted therapies.

Progenitor-derived endothelin controls dermal sheath contraction for hair follicle regression

Substantial follicle remodelling during the regression phase of the hair growth cycle is coordinated by the contraction of the dermal sheath smooth muscle, but how dermal-sheath-generated forces are regulated is unclear. Here, we identify spatiotemporally controlled endothelin signalling-a potent vasoconstriction-regulating pathway-as the key activating mechanism of dermal sheath contraction. Pharmacological blocking or genetic ablation of both endothelin receptors, ET_A and ET_B, impedes dermal sheath contraction and halts follicle regression. Epithelial progenitors at the club hair-epithelial strand bottleneck produce the endothelin ligand ET-1, which is required for follicle regression. ET signalling in dermal sheath cells and downstream contraction is dynamically regulated by cytoplasmic Ca²⁺ levels through cell membrane and sarcoplasmic reticulum calcium channels. Together, these findings illuminate an epithelial-mesenchymal interaction paradigm in which progenitors-destined to undergo programmed cell death-control the contraction of the surrounding sheath smooth muscle to orchestrate homeostatic tissue regression and reorganization for the next stem cell activation and regeneration cycle.

Don't Turn Off the Tap! The Importance of Discovery Science to the Australian Cardiovascular Sector and Improving Clinical Outcomes Into the Future

Despite significant advances in interventional and therapeutic approaches, cardiovascular disease (CVD) remains the leading cause of death and mortality. To lower this health burden, cardiovascular discovery scientists need to play an integral part in the solution. Successful clinical translation is achieved when built upon a strong foundational understanding of the disease mechanisms involved. Changes in the Australian funding landscape, to place greater emphasis on translation, however, have increased job insecurity for discovery science researchers and especially early-mid career researchers. To highlight the importance of discovery science in cardiovascular research, this review compiles six science stories in which fundamental discoveries, often involving Australian researchers, has led to or is advancing to clinical translation. These stories demonstrate the importance of the role of discovery scientists and the need for their work to be prioritised now and in the future. Australia needs to keep discovery scientists supported and fully engaged within the broader cardiovascular research ecosystem so they can help realise the next game-changing therapy or diagnostic approach that diminishes the burden of CVD on society.

Paracrine Role of the Endothelium in Metabolic Homeostasis in Health and Nutrient Excess

The vascular endothelium traditionally viewed as a simple physical barrier between the circulation and tissue is now well-established as a key organ mediating whole organism homeostasis by release of a portfolio of anti-inflammatory and pro-inflammatory vasoactive molecules. Healthy endothelium releases anti-inflammatory signaling molecules such as nitric oxide and prostacyclin; in contrast, diseased endothelium secretes pro-inflammatory signals such as reactive oxygen species, endothelin-1 and tumor necrosis factor-alpha (TNFα). Endothelial dysfunction, which has now been identified as a hallmark of different components of the cardiometabolic syndrome including obesity, type 2 diabetes and hypertension, initiates and drives the progression of tissue damage in these disorders. Recently it has become apparent that, in addition to vasoactive molecules, the vascular endothelium has the potential to secrete a diverse range of small molecules and proteins mediating metabolic processes in adipose tissue (AT), liver, skeletal muscle and the pancreas. AT plays a pivotal role in orchestrating whole-body energy homeostasis and AT dysfunction, characterized by local and systemic inflammation, is central to the metabolic complications of obesity. Thus, understanding and targeting the crosstalk between the endothelium and AT may generate novel therapeutic opportunities for the cardiometabolic syndrome. Here, we provide an overview of the role of the endothelial secretome in controlling the function of AT. The endothelial-derived metabolic regulatory factors are grouped and discussed based on their physical properties and their downstream signaling effects. In addition, we focus on the therapeutic potential of these regulatory factors in treating cardiometabolic syndrome, and discuss areas of future study of potential translatable and clinical significance. The vascular endothelium is emerging as an important paracrine/endocrine organ that secretes regulatory factors in response to nutritional and environmental cues. Endothelial dysfunction may result in imbalanced secretion of these regulatory factors and contribute to the progression of AT and whole body metabolic dysfunction. As the vascular endothelium is the first responder to local nutritional changes and adipocyte-derived signals, future work elucidating the changes in the endothelial secretome is crucial to improve our understanding of the pathophysiology of cardiometabolic disease, and in aiding our development of new therapeutic strategies to treat and prevent cardiometabolic syndrome.

The microvascular hypothesis underlying neurologic manifestations of long COVID-19 and possible therapeutic strategies

With the ongoing distribution of the coronavirus disease (COVID) vaccines, the pandemic of our age is ending, leaving the world to deal with its well-documented aftereffects. Long COVID comprises a variety of symptoms, of which the neurological component prevails. The most permeating theory on the genesis of these symptoms builds upon the development of microvascular dysfunction similar to that seen in numerous vascular diseases such as diabetes. This can occur through the peripheral activation of angiotensin-converting enzyme 2 receptors, or through exacerbations of pro-inflammatory cytokines that can remain in circulation even after the infection diminishes. Several drugs have been identified to act on the neurovascular unit to promote repair, such as gliptins, and others. They also succeeded in improving neurologic outcome in diabetic patients. The repurposing of such drugs for treatment of long COVID-19 can possibly shorten the time to recovery of long COVID-19 syndrome.

COVID-19: The Impact on Cardiovascular System

SARS-CoV-2 has been circulating in population worldwide for the past year and a half, and thus a vast amount of scientific literature has been produced in order to study the biology of the virus and the pathophysiology of COVID-19, as well as to determine the best way to prevent infection, treat the patients and eliminate the virus. SARS-CoV-2 binding to the ACE2 receptor is the key initiator of COVID-19. The ability of SARS-CoV-2 to infect various types of cells requires special attention to be given to the cardiovascular system, as it is commonly affected. Thorough diagnostics and patient monitoring are beneficial in reducing the risk of cardiovascular morbidity and to ensure the most favorable outcomes for the infected patients, even after they are cured of the acute disease. The multidisciplinary nature of the fight against the COVID-19 pandemic requires careful consideration from the attending clinicians, in order to provide fast and reliable treatment to their patients in accordance with evidence-based medicine principles. In this narrative review, we reviewed the available literature on cardiovascular implications of COVID-19; both the acute and the chronic.

Reciprocal organ interactions during heart failure: a position paper from the ESC Working Group on Myocardial Function

Heart failure-either with reduced or preserved ejection fraction (HFrEF/HFpEF)-is a clinical syndrome of multifactorial and gender-dependent aetiology, indicating the insufficiency of the heart to pump blood adequately to maintain blood flow to meet the body's needs. Typical symptoms commonly include shortness of breath, excessive fatigue with impaired exercise capacity, and peripheral oedema, thereby alluding to the fact that heart failure is a syndrome that affects multiple organ systems. Patients suffering from progressed heart failure have a very limited life expectancy, lower than that of numerous cancer types. In this position paper, we provide an overview regarding interactions between the heart and other organ systems, the clinical evidence, underlying mechanisms, potential available or yet-to-establish animal models to study such interactions and finally discuss potential new drug interventions to be developed in the future. Our working group suggests that more experimental research is required to understand the individual molecular mechanisms underlying heart failure and reinforces the urgency for tailored therapeutic interventions that target not only the heart but also other related affected organ systems to effectively treat heart failure as a clinical syndrome that affects and involves multiple organs.

3'-Oxo-tabernaelegantine A (OTNA) selectively relaxes pulmonary arteries by inhibiting AhR

BACKGROUND

Pulmonary arterial hypertension (PAH), characterized by pulmonary artery constriction and vascular remodeling, has a high mortality rate. New drugs for the treatment of PAH urgently need to be developed.

PURPOSE

This study was designed to investigate the vasorelaxant activity of OTNA in isolated pulmonary arteries, and explore its molecular mechanism.

METHODS

Pulmonary arteries and thoracic aortas were isolated from mice, and vascular tone was tested with a Wire Myograph System. Nitric oxide levels were determined with DAF-FM DA and DAX-J2™ Red. Cellular thermal shift assays, microscale thermophoresis, and molecular docking were used to identify the interaction between OTNA and aryl hydrocarbon receptor (AhR). The levels of PI3K, p-PI3K, Akt, p-Akt, eNOS, p-eNOS, and AhR were analyzed by Western blotting.

RESULTS

OTNA selectively relaxed the isolated pulmonary artery rings in an endothelium-dependent manner. Mechanistic study showed that OTNA induced NO production through activation of the PI3K/Akt/eNOS pathway in endothelial cells. Furthermore, we also found that OTNA directly bound to AhR and activated the PI3K/Akt/eNOS pathway to dilate pulmonary arteries by inhibiting AhR.

CONCLUSIONS

OTNA relaxes pulmonary arteries by antagonizing AhR. This study provides a new natural antagonist of AhR as a promising lead compound for PAH treatment.

The Local Regulation of Vascular Function: From an Inside-Outside to an Outside-Inside Model

Our understanding of the regulation of vascular function, specifically that of vasomotion, has evolved dramatically over the past few decades. The classic conception of a vascular system solely regulated by circulating hormones and sympathetic innervation gave way to a vision of a local regulation. Initially by the so-called, autacoids like prostacyclin, which represented the first endothelium-derived paracrine regulator of smooth muscle. This was the prelude of the EDRF-nitric oxide age that has occupied vascular scientists for nearly 30 years. Endothelial cells revealed to have the ability to generate numerous mediators besides prostacyclin and nitric oxide (NO). The need to classify these substances led to the coining of the terms: endothelium-derived relaxing, hyperpolarizing and contracting factors, which included various prostaglandins, thromboxane A2, endothelin, as well numerous candidates for the hyperpolarizing factor. The opposite layer of the vascular wall, the adventitia, eventually and for a quite short period of time, enjoyed the attention of some vascular physiologists. Adventitial fibroblasts were recognized as paracrine cells to the smooth muscle because of their ability to produce some substances such as superoxide. Remarkably, this took place before our awareness of the functional potential of another adventitial cell, the adipocyte. Possibly, because the perivascular adipose tissue (PVAT) was systematically removed during the experiments as considered a non-vascular artifact tissue, it took quite long to be considered a major source of paracrine substances. These are now being integrated in the vast pool of mediators synthesized by adipocytes, known as adipokines. They include hormones involved in metabolic regulation, like leptin or adiponectin; classic vascular mediators like NO, angiotensin II or catecholamines; and inflammatory mediators or adipocytokines. The first substance studied was an anti-contractile factor named adipose-derived relaxing factor of uncertain chemical nature but possibly, some of the relaxing mediators mentioned above are behind this factor. This manuscript intends to review the vascular regulation from the point of view of the paracrine control exerted by the cells present in the vascular environment, namely, endothelial, adventitial, adipocyte and vascular stromal cells.

Pancreatic Blood Flow with Special Emphasis on Blood Perfusion of the Islets of Langerhans

The pancreatic islets are more richly vascularized than the exocrine pancreas, and possess a 5- to 10-fold higher basal and stimulated blood flow, which is separately regulated. This is reflected in the vascular anatomy of the pancreas where islets have separate arterioles. There is also an insulo-acinar portal system, where numerous venules connect each islet to the acinar capillaries. Both islets and acini possess strong metabolic regulation of their blood perfusion. Of particular importance, especially in the islets, is adenosine and ATP/ADP. Basal and stimulated blood flow is modified by local endothelial mediators, the nervous system as well as gastrointestinal hormones. Normally the responses to the nervous system, especially the parasympathetic and sympathetic nerves, are fairly similar in endocrine and exocrine parts. The islets seem to be more sensitive to the effects of endothelial mediators, especially nitric oxide, which is a permissive factor to maintain the high basal islet blood flow. The gastrointestinal hormones with pancreatic effects mainly influence the exocrine pancreatic blood flow, whereas islets are less affected. A notable exception is incretin hormones and adipokines, which preferentially affect islet vasculature. Islet hormones can influence both exocrine and endocrine blood vessels, and these complex effects are discussed. Secondary changes in pancreatic and islet blood flow occur during several conditions. To what extent changes in blood perfusion may affect the pathogenesis of pancreatic diseases is discussed. Both type 2 diabetes mellitus and acute pancreatitis are conditions where we think there is evidence that blood flow may contribute to disease manifestations. © 2019 American Physiological Society. Compr Physiol 9:799-837, 2019.

Potassium channels contribute to the increased sensitivity of the rabbit carotid artery to hydrogen sulfide in diabetes

Hydrogen sulfide (H₂S) is a potential endothelium-derived hyperpolarizing factor (EDHF) and adventitium- or adipocyte-derived relaxing factor (ADRF) which vasorelaxant action is mediated by potassium channels. H₂S could also play an important role in the pathophysiology of diabetic cardiovascular complications. The present study has investigated the influence of alloxan-induced diabetes on the role of potassium channels mediating the relaxant response of the rabbit carotid artery to NaHS, a donor of H₂S. NaHS (10^-8-3 × 10^-5 M) relaxed phenylephrine-precontracted carotid arteries, with higher potency in diabetic than in control rabbits. The selective blockers of potassium channels charybdotoxin, 4-amynopiridine and glibenclamide significantly inhibited the relaxant action of NaHS in diabetic rabbits, but not in control rabbits. When compared to control rabbits, carotid arteries from diabetic rabbits showed significantly reduced expression of big conductance Ca⁺²-activated potassium channels (BK_Ca), significantly enhanced expression of intermediate conductance Ca⁺²-activated potassium channels (IK_Ca) and not significant different expression of voltage-sensitive potassium channels (K_V) and ATP-sensitive potassium channels (K_ATP). These results suggest that an enhanced role of IK_Ca, K_V and K_ATP potassium channels could be involved in the increased sensitivity of the rabbit carotid artery to H₂S in diabetes.

Epicatechin's cardiovascular protective effects are mediated via opioid receptors and nitric oxide

PURPOSE

Cardiovascular disease is the leading cause of mortality globally. Epicatechin has previously been shown to improve vascular responses and possess cardioprotective properties. However, the mechanisms underpinning these cardiotropic outcomes remain unknown. The aim of this study was to further identify epicatechin's mechanism of action in the cardiovasculature.

METHODS

The effects of epicatechin on isolated rat conduit arteries, resistance vessels and cardiac electrophysiology were investigated on resting tension and precontracted vessels and cardiac action potential parameters, both in the presence and in the absence of various antagonists.

RESULTS

At resting tension, epicatechin alone did not affect the vasoreactivity of either conduit or resistance vessels. In noradrenaline pre-contracted thoracic aortic arteries and potassium chloride pre-contracted mesenteric vessels, epicatechin (10^-9-10^-4 M) induced significant vasorelaxation. The addition of naloxone (10^-5 M), N^G-nitro-L-arginine methyl ester (10^-5M), 4-aminopyridine (5 mM) and verapamil (10^-5 M) attenuated epicatechin-mediated vasorelaxation. No change in epicatechin-mediated vasorelaxation was observed with the addition of atropine (10^-5 M). Epicatechin significantly improved cardiac electrophysiology by reducing the resting membrane potential, action potential amplitude and force of contraction that was mitigated following the addition of naloxone (10^-5 M). Epicatechin significantly decreased the action potential duration at 20, 50 and 90% duration and time to 90% relaxation of force that was unchanged following the addition of naloxone (10^-5 M).

CONCLUSIONS

These findings suggest epicatechin's vascular responses and cardioprotective effects are mediated through opioid receptors, nitric oxide, potassium channel and calcium channel activation and highlight the importance of the endothelium/nitric oxide in epicatechin mediated vasorelaxation.

Anti-Inflammatory Effects of Melatonin in Obesity and Hypertension

PURPOSE OF REVIEW

Here, we review the known relations between hypertension and obesity to inflammation and postulate the endogenous protective effect of melatonin and its potential as a therapeutic agent. We will describe the multiple effects of melatonin on blood pressure, adiposity, body weight, and focus on mitochondrial-related anti-inflammatory and antioxidant protective effects.

RECENT FINDINGS

Hypertension and obesity are usually associated with systemic and tissular inflammation. The progressive affection of target-organs involves multiple mediators of inflammation, most of them redundant, which make anti-inflammatory strategies ineffective. Melatonin reduces blood pressure, body weight, and inflammation. The mechanisms of action of this ancient molecule of protection involve multiple levels of action, from subcellular to intercellular. Mitochondria is a key inflammatory element in vascular and adipose tissue and a potential pharmacological target. Melatonin protects against mitochondrial dysfunction. Melatonin reduces blood pressure and adipose tissue dysfunction by multiple anti-inflammatory/antioxidant actions and provides potent protection against mitochondria-mediated injury in hypertension and obesity. This inexpensive and multitarget molecule has great therapeutic potential against both epidemic diseases.

Xyloketal B exerts antihypertensive effect in renovascular hypertensive rats via the NO-sGC-cGMP pathway and calcium signaling

Xyloketal B (Xyl-B) is a novel marine compound isolated from mangrove fungus Xylaria sp. (No 2508). We previously showed that Xyl-B promoted endothelial NO release and protected against atherosclerosis through the Akt/eNOS pathway. Vascular NO production regulates vasoconstriction in central and peripheral arteries and plays an important role in blood pressure control. In this study, we examined whether Xyl-B exerted an antihypertensive effect in a hypertensive rat model, and further explored the possible mechanisms underlying its antihypertensive action. Administration of Xyl-B (20 mg·kg^-1·d^-1, ip, for 12 weeks) significantly decreased the systolic and diastolic blood pressure in a two-kidney, two-clip (2K2C) renovascular hypertensive rats. In endothelium-intact and endothelium-denuded thoracic aortic rings, pretreatment with Xyl-B (20 μmol/L) significantly suppressed phenylephrine (Phe)-induced contractions, suggesting that its vasorelaxant effect was attributed to both endothelial-dependent and endothelial-independent mechanisms. We used SNP, methylene blue (MB, guanylate cyclase inhibitor) and indomethacin (IMC, cyclooxygenase inhibitor) to examine which endothelial pathway was involved, and found that MB, but not IMC, reversed the inhibitory effects of Xyl-B on Phe-induced vasocontraction. Moreover, Xyl-B increased the endothelial NO bioactivity and smooth muscle cGMP level, revealing that the NO-sGC-cGMP pathway, rather than PGI₂, mediated the anti-hypertensive effect of Xyl-B. We further showed that Xyl-B significantly attenuated KCl-induced Ca²⁺ entry in smooth muscle cells in vitro, which was supposed to be mediated by voltage-dependent Ca²⁺ channels (VDCCs), and reduced ryanodine-induced aortic contractions, which may be associated with store-operated Ca²⁺ entry (SOCE). Taken together, these findings demonstrate that Xyl-B exerts significant antihypertensive effects not only through the endothelial NO-sGC-cGMP pathway but also through smooth muscle calcium signaling, including VDCCs and SOCE.

Cellular mechanisms underlying obesity-induced arterial stiffness

Obesity is an emerging pandemic driven by consumption of a diet rich in fat and highly refined carbohydrates (a Western diet) and a sedentary lifestyle in both children and adults. There is mounting evidence that arterial stiffness in obesity is an independent and strong predictor of cardiovascular disease (CVD), cognitive functional decline, and chronic kidney disease. Cardiovascular stiffness is a precursor to atherosclerosis, systolic hypertension, cardiac diastolic dysfunction, and impairment of coronary and cerebral flow. Moreover, premenopausal women lose the CVD protection normally afforded to them in the setting of obesity, insulin resistance, and diabetes, and this loss of CVD protection is inextricably linked to an increased propensity for arterial stiffness. Stiffness of endothelial and vascular smooth muscle cells, extracellular matrix remodeling, perivascular adipose tissue inflammation, and immune cell dysfunction contribute to the development of arterial stiffness in obesity. Enhanced endothelial cortical stiffness decreases endothelial generation of nitric oxide, and increased oxidative stress promotes destruction of nitric oxide. Our research over the past 5 years has underscored an important role of increased aldosterone and vascular mineralocorticoid receptor activation in driving development of cardiovascular stiffness, especially in females consuming a Western diet. In this review the cellular mechanisms of obesity-associated arterial stiffness are highlighted.

Venous endothelium reactivity to Angiotensin II: A study in primary endothelial cultures of rat vena cava and portal vein

The role of the vascular endothelium in modulating the arterial system has been widely investigated, but poorly explored at the venous site. In the present work, primary cultures of venous endothelium from rat Vena Cava (VC) and Portal Vein (PV) were established, characterized and analyzed according to their growth pattern and ability to produce nitric oxide (NO) and prostanoids (PGF_{2 α} and PGI₂), at basal state and after stimulation with Angiotensin II (Ang II, 1μmol/L). Basal NO was detected in all examined cells in culture. Pre-incubation with Ang II increased NO production in cells from VC (but not in PV cultures), through activation of both AT₁ and AT₂ receptors. Both cultures exhibited detectable levels of PGF_{2 α} at resting conditions, which were similarly enhanced by Ang II. Basal PGI₂ levels were higher in PV, but increased after Ang II treatment in VC, with no further effect on PV cells. We conclude that endothelial cells from VC and PV exhibit important properties and react to Ang II, probably influencing the whole circulatory system. This experimental cell model gives support to further studies concerning intracellular pathways of the venous endothelium, analyzed in separate from the vascular smooth muscle wall.

Alteration of Vascular Responsiveness to Uridine Adenosine Tetraphosphate in Aortas Isolated from Male Diabetic Otsuka Long-Evans Tokushima Fatty Rats: The Involvement of Prostanoids

We investigated whether responsiveness to dinucleotide uridine adenosine tetraphosphate (Up₄A) was altered in aortas from type 2 diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats compared with those from age-matched control Long-Evans Tokushima Otsuka (LETO) rats at the chronic stage of disease. In OLETF aortas, we observed the following: (1) Up₄A-induced contractions were lower than those in the LETO aortas under basal conditions, (2) slight relaxation occurred due to Up₄A, but this was not observed in phenylephrine-precontracted LETO aortas, (3) acetylcholine-induced relaxation was reduced (vs. LETO), and (4) prostanoid release (prostaglandin (PG)F_2α, thromboxane (Tx)A₂ metabolite, and PGE₂) due to Up₄A was decreased (vs. LETO). Endothelial denudation suppressed Up₄A-induced contractions in the LETO group, but increased the contractions in the OLETF group. Under nitric oxide synthase (NOS) inhibition, Up₄A induced contractions in phenylephrine-precontracted aortas; this effect was greater in the LETO group (vs. the OLETF group). The relaxation response induced by Up₄A was unmasked by cyclooxygenase inhibitors, especially in the LETO group, but this effect was abolished by NOS inhibition. These results suggest that the relaxant component of the Up₄A-mediated response was masked by prostanoids in the LETO aortas and that the LETO and OLETF rats presented different contributions of the endothelium to the response.

Low-intensity Extracorporeal Shock Wave Therapy for Erectile Dysfunction: A Systematic Review and Meta-analysis

OBJECTIVE

To assess the efficacy of low-energy extracorporeal shock wave therapy (LI-ESWT) for erectile dysfunction (ED), a systematic review and meta-analysis was undertaken.

METHODS

A comprehensive search of the PubMed, Cochrane Register, and Embase databases to March 2017 was performed for randomized controlled trials reporting on patients with ED treated with LI-ESWT. The International Index of Erectile Function (IIEF) and the Erection Hardness Score (EHS) were the most commonly used tools to evaluate the therapeutic efficacy of LI-ESWT.

RESULTS

There were 9 studies including 637 patients from 2005 to 2017. The meta-analysis revealed that LI-ESWT could significantly improve IIEF (mean difference [MD]: 2.54; 95% confidence interval [CI], 0.83-4.25; P = .004) and EHS (risk difference [RD]: 0.16; 95% CI, 0.03-0.28; P = .01). Therapeutic efficacy could last at least 3 months (MD: 4.15; 95% CI, 1.40-6.90; P = .003). Lower energy density (0.09 mJ/mm², MD: 4.14; 95% CI, 0.87-7.42; P = .01) increased the number of pulses (3000 pulses per treatment, MD: 5.11; 95% CI, 3.18-7.05, P < .0001) and shorter total treatment courses (<6 weeks, MD: 3.73; 95% CI, 0.54-6.93; P = .02) resulted in better therapeutic efficacy.

CONCLUSION

These studies suggest that LI-ESWT could significantly improve the IIEF and EHS of patients with ED. The publication of robust evidence from additional randomized controlled trials and longer-term follow-up would provide more confidence regarding the use of LI-ESWT for patients with ED.

Sex differences in the regulation of porcine coronary artery tone by perivascular adipose tissue: a role of adiponectin?

BACKGROUND AND PURPOSE

As there is sexual dimorphism in the regulation of vascular tone, the aim of this present study was to determine whether there are sex differences in perivascular adipose tissue (PVAT)-mediated regulation of the porcine coronary artery (PCA) tone.

EXPERIMENTAL APPROACH

Isometric tension recording system was used to record changes in tone in PCAs. Western blot analysis was performed to examine the expression of adiponectin in PVAT and adiponectin receptors and adiponectin binding protein (APPL1) in PCA. The level of adiponectin released from PVAT was measured using elisa.

KEY RESULTS

In the presence of adherent PVAT, contractions to the thromboxane mimetic U46619 and endothelin-1 were significantly reduced in PCAs from females, but not males. In PCAs pre-contracted with U46619, re-addition of PVAT caused relaxation in PCAs from females, but not males. This relaxant response in females was attenuated by combined inhibition of NOS (with L-NAME) and COX (with indomethacin). Pre-incubation with an anti-adiponectin antibody abolished the relaxant effects of PVAT. The adiponectin receptor agonist (adipoRon) produced a greater relaxation in PCAs from females compared with males. However, there was no difference in either the expression or release of adiponectin from PVAT between sexes. Similarly, there was no difference in the expression of adiponectin receptors or the adiponectin receptor adaptor protein APPL1 in PCAs.

CONCLUSION AND IMPLICATIONS

These findings demonstrate a clear sex difference in the regulation of coronary arterial tone in response to adiponectin receptor stimulation, which may underlie the anticontractile effects of PVAT in females.

Recent Pathophysiological Aspects of Peyronie's Disease: Role of Free Radicals, Rationale, and Therapeutic Implications for Antioxidant Treatment-Literature Review

Peyronie's disease (PD) is a chronic inflammation of tunica albuginea of the corpora cavernosa that causes an inelastic plaque resulting in penis deformation. Although its etiology is not completely known, there is general consensus that PD is genetically transmitted and secondary to penile trauma. In recent years, numerous studies demonstrated the role played by oxidative stress in PD pathogenesis, and other studies have described successful use of antioxidants in PD treatment. Oxidative stress is an integral part of this disease, influencing its progression. In the early stages of PD, the inflammatory infiltrate cells produce high quantities of free radicals and proinflammatory and profibrotic cytokines, with consequent activation of transcription factor NF-κB. While conservative therapies commonly used in the early stages of PD include oral substances (Potaba, tamoxifen, colchicine, and vitamin E), intralesional treatment (verapamil, interferon, steroids, and more recently collagenase clostridium histolyticum-Xiaflex), and local physical treatment (iontophoresis, extracorporeal shock wave therapy, and penile extender), the significant results obtained by emerging treatments with the antioxidants cited in this article suggest these therapeutic agents interfere at several levels with the disease's pathogenetic mechanisms. Antioxidants therapy outcomes are interesting for good clinical practice and also confirm the fundamental role played by oxidative stress in PD.

Endothelial Function in Children and Adolescents Is Mainly Influenced by Age, Sex and Physical Activity - An Analysis of Reactive Hyperemic Peripheral Artery Tonometry

BACKGROUND

As adolescents rarely experience cardiovascular events, surrogate markers of atherosclerosis are useful to justify and monitor effects of primary prevention and therapy of risk factors. Endothelial function assessed by reactive hyperemic peripheral arterial tonometry (RH-PAT) resulting in a reactive hyperemic index (RHI) is a noninvasive method with limited data for use in children and adolescents.Methods and Results:We performed a total of 931 RHI measurements in 445 high-school students, aged 10-17 years, over a time period of 5 years. Students were randomized by class to 60 min physical exercise (PE) at school daily (intervention group), or 2 units of 45-min PE weekly (control group). To characterize the factors influencing the RHI, anthropometry, cardiopulmonary exercise testing, blood cholesterol and quality of life were assessed and used to build mixed linear models. Main influential factors were age, with an increase of RHI from 1.53±0.42 in the youngest to 1.96±0.59 in the oldest students, sex, with higher values in girls, and physical activity. This increase adjusted by age and sex was estimated as 0.11 [0.08, 0.14] per year. RHI was higher in the intervention group by 0.09 [-0.05, 0.23] in comparison with the control group.

CONCLUSIONS

If RH-PAT is used in research or as a clinical tool in adolescents, the shown age- and sex-dependence of RHI have to be taken in account.

Imatinib relaxes the pulmonary venous bed of guinea pigs

Background

Recently, the IMPRES study revealed that systemic imatinib improves exercise capacity in patients with advanced pulmonary arterial hypertension. Imatinib blocks the tyrosine kinase activity of the platelet-derived growth factor (PDGF)-receptor (PDGFR), acts antiproliferative and relaxes pulmonary arteries. However so far, the relaxant effects of imatinib on pulmonary veins (PVs) and on the postcapillary resistance are unknown, although pulmonary hypertension (PH) due to left heart disease (LHD) is most common and primarily affects PVs. Next, it is unknown whether activation of PDGFR alters the pulmonary venous tone. Due to the reported adverse effects of systemic imatinib, we evaluated the effects of nebulized imatinib on the postcapillary resistance.

Methods

Precision-cut lung slices (PCLS) were prepared from guinea pigs. PVs were pre-constricted with Endothelin-1 (ET-1) and the imatinib-induced relaxation was studied by videomicroscopy; PDGF-BB-related vascular properties were evaluated as well. The effects of perfused/nebulized imatinib on the postcapillary resistance were studied in cavine isolated perfused lungs (IPL). Intracellular cAMP/cGMP was measured by ELISA in PVs.

Results

In PCLS, imatinib (100 μM) relaxed pre-constricted PVs (126%). In PVs, imatinib increased cAMP, but not cGMP and inhibition of adenyl cyclase or protein kinase A reduced the imatinib-induced relaxation. Further, inhibition of K_ATP-channels, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {\mathrm{BK}}_{\mathrm{Ca}}^{2+} $$\end{document}BKCa2+-channels or K_v-channels diminished the imatinib-induced relaxation, whereas inhibition of NO-signaling was without effect. In the IPL, perfusion or nebulization of imatinib reduced the ET-1-induced increase of the postcapillary resistance. In PCLS, PDGF-BB contracted PVs, which was blocked by imatinib and by the PDGFR-β kinase inhibitor SU6668, whereas inhibition of PDGFR-α (ponatinib) had no significant effect. Conversely, PDGFR-β kinase inhibitors (SU6668/DMPQ) relaxed PVs pre-constricted with ET-1 comparable to imatinib, whereas the PDGFR-α kinase inhibitor ponatinib did not.

Conclusions

Imatinib-induced relaxation depends on cAMP and on the activation of K⁺-channels. Perfused or nebulized imatinib significantly reduces the postcapillary resistance in the pre-constricted (ET-1) pulmonary venous bed. Hence, nebulization of imatinib is feasible and might reduce systemic side effects. Conversely, PDGF-BB contracts PVs by activation of PDGFR-β suggesting that imatinib-induced relaxation depends on PDGFR-β-antagonism. Imatinib combines short-term relaxant and long-term antiproliferative effects. Thus, imatinib might be a promising therapy for PH due to LHD.