Pressure Regulation Research Articles

In vitro inhibitor effect and molecular docking of thiamine (vitamin B1), riboflavin (vitamin B2), and reference inhibitor captopril on angiotensin-converting enzyme purified from sheep plasma.

Angiotensin-converting enzyme (ACE, EC 3.4.15.1) is a very important factor in the regulation of blood pressure. Also, the inhibition of ACE with natural compounds has been a very important research area in the treatment of high blood pressure. ACE was purified and characterized from sheep plasma. Molecular docking studies and the inhibition effect of thiamine, riboflavin, and captopril on ACE were investigated. Herein, ACE was purified from sheep plasma by affinity chromatography. The effect of thiamine and riboflavin on ACE was researched. Molecular docking studies were performed to understand the molecular interactions between thiamine, riboflavin, and captopril with ACE. The purification coefficient was found to be 8636 fold. The binding energy of thiamine, riboflavin, and captopril was found to be -6.7 kcal/mol, -8.1 kcal/mol, and -5.5 kcal/mol, respectively. Thiamine conformed to three conventional hydrogen bonds with ASP:415, HIS:513, and LYS:454. Riboflavin formed four conventional hydrogen bonds with GLN:281, GLU:376, THR:282, and TYR:520. Captopril formed two conventional hydrogen bonds with ARG:124, one conventional hydrogen bond with TYR:62 and ASN:85, and one carbon-hydrogen bond with ASN:66. Molecular docking results showed that thiamine, riboflavin, and captopril interacted with ACE through hydrogen bonding and hydrophobic interactions. Thiamine and riboflavin indicated significant inhibition effects on ACE. The IC50 values of thiamine, riboflavin, and captopril were found as 960.56 µM, 11.02 µM, and 1.60 nM, respectively. Ki values for thiamine, riboflavin, and captopril were determined as 1352.04 µM, 12.30 µM, and 1.06 nM, respectively. In this work, it was concluded that thiamine and riboflavin may have preventive and therapeutical impacts against high blood pressure with their ACE inhibitor effect. Thiamine and riboflavin showed a lower inhibitory effect with a higher IC50 than captopril. However, when the inhibitory effect of thiamine and riboflavin vitamins is compared to captopril, it is concluded that they may be natural inhibitors with fewer side effects.

First, a seat; then, an upgrade.

The Sir Stanley Peart Essay Competition is an annual event run by the British and Irish Hypertension Society to encourage Early Career Researchers to continue the ethos of Sir Stanley Peart. Sir Stanley Peart was a clinician and clinical researcher who made a major contribution to our understanding of blood pressure regulation. He was the first to demonstrate the release of noradrenaline in response to sympathetic nerve stimulation. He was also the first to purify, and determine the structure of, angiotensin and he later isolated the enzyme, renin, and carried out many important investigations of the factors controlling its release in the body. This year, the essay topic was "Do we need new classes of antihypertensive drugs?". In his prize-winning essay, "First, a seat; then, an upgrade", Dr Sathyanarayanan argues that we do not need new classes of antihypertensive drugs, instead we should focus our attention on addressing the factors that lead to high blood pressure in the first place and use our existing drug classes more effectively.

Intra- and postoperative relative angiotensin II deficiency in patients undergoing elective major abdominal surgery

IntroductionThe classical axis of the renin–angiotensin system (RAS) makes an important contribution to blood pressure regulation under general anesthesia via the vasopressor angiotensin II (Ang II). As part of the alternative RAS, angiotensin-converting enzyme 2 (ACE2) modulates the pro-inflammatory and fibrotic effects of Ang II by processing it into the organ-protective Ang 1–7, which is cleaved to Ang 1–5 by ACE. Although the levels of ACE2 may be associated with postoperative complications, alternative RAS metabolites have never been studied perioperatively. This study was designed to investigate the perioperative kinetics and balance of both RAS axes around major abdominal surgery.MethodsIn this observational cohort study, 35 patients undergoing elective major abdominal surgery were included. Blood sampling was performed before and after induction of anesthesia, at 1 h after skin incision, at the end of surgery, and on postoperative days (POD) 1, 3, and 7. The equilibrium concentrations of Ang I–IV, Ang 1–7, and Ang 1–5 in plasma were quantified using mass spectrometry. The plasma protein levels of ACE and ACE2 were measured with ELISA.ResultsSurgery caused a rapid, transient, and primarily renin-dependent activation of both RAS axes that returned to baseline on POD 1, followed by suppression. After induction, the Ang II/Ang I ratio persistently decreased, while the ACE levels started to increase on POD 1 (all p < 0.01 versus before anesthesia). Conversely, the ACE2 levels increased on POD 3 and 7 (both p < 0.001 versus before anesthesia), when the median Ang 1–7 concentrations were unquantifiably low.DiscussionThe postoperative elevation of ACE2 may prolong the decrease of the Ang II/Ang I ratio through the increased processing of Ang II. Further clarification of the intraoperative factors leading to relative Ang II deficiency and the sources of postoperatively elevated ACE2 is warranted.

Optimizing Energy Efficiency and Environmental Sustainability in Gas Distribution Station: A Comprehensive Analysis and Technological Solutions

It is important to address the world‘s energy crisis, increasing energy demand and changing climate by finding ways to recover unused energy and minimise primary and secondary energy use and emissions. The natural gas sector, which consists of the transmission network and gas distribution stations, is an important part of the global and Lithuanian energy sector. However, due to the operating principle of gas pressure regulators, the energy potential of high-pressure gas is not efficiently utilized in gas distribution stations. As a result, natural gas boilers are used for gas preheating, and gas distribution stations cause additional environmental pollution. This study aims to find ways to optimise the efficiency of gas distribution stations and reduce their negative environmental impact by identifying areas where energy is wasted and proposing alternative technological solutions: turbine expander (as an alternative for gas pressure regulator), ground heat pumps, solar collectors and photovoltaic solar cells (as gas preheating alternatives). The best alternative technological solution for the gas distribution station is evaluated based on energy efficiency, economic viability, and environmental impact (3E criteria).

The Interaction of Vasopressin with Hormones of the Hypothalamo–Pituitary–Adrenal Axis: The Significance for Therapeutic Strategies in Cardiovascular and Metabolic Diseases

A large body of evidence indicates that vasopressin (AVP) and steroid hormones are frequently secreted together and closely cooperate in the regulation of blood pressure, metabolism, water–electrolyte balance, and behavior, thereby securing survival and the comfort of life. Vasopressin cooperates with hormones of the hypothalamo–pituitary–adrenal axis (HPA) at several levels through regulation of the release of corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), and multiple steroid hormones, as well as through interactions with steroids in the target organs. These interactions are facilitated by positive and negative feedback between specific components of the HPA. Altogether, AVP and the HPA cooperate closely as a coordinated functional AVP-HPA system. It has been shown that cooperation between AVP and steroid hormones may be affected by cellular stress combined with hypoxia, and by metabolic, cardiovascular, and respiratory disorders; neurogenic stress; and inflammation. Growing evidence indicates that central and peripheral interactions between AVP and steroid hormones are reprogrammed in cardiovascular and metabolic diseases and that these rearrangements exert either beneficial or harmful effects. The present review highlights specific mechanisms of the interactions between AVP and steroids at cellular and systemic levels and analyses the consequences of the inappropriate cooperation of various components of the AVP-HPA system for the pathogenesis of cardiovascular and metabolic diseases.

Losing, regaining, and continuing to build self-confidence – a qualitative, phenomenological study of being physically active with a type B aortic dissection

Purpose To gain a comprehensive understanding of experiences related to being physically active in participants with an uncomplicated type B aortic dissection. Materials and methods We performed a qualitative, phenomenological study. First-person accounts of adults, who at least one year ago had an uncomplicated type B aortic dissection, were collected using semi-structured interviews. The audio recordings of the interviews were transcribed verbatim and analyzed with interpretative phenomenological analysis. Results We collected, in total, 644 min interview data from 14 participants. Three patterns were interpreted: losing self-confidence, regaining self-confidence, and continuing to build self-confidence. Experiencing symptoms when pushing limits, challenges with energy management, and side effects of medication caused loss of self-confidence. Changes in identity, reaching milestones that reflect improvement, and support from others and tools helped participants regain self-confidence. To continuing to build self-confidence, participants indicated they needed success experiences and activities make life worth living. Conclusions Self-confidence in adults with an uncomplicated type B aortic dissection changes immediately after the diagnosis of the aortic dissection. Rehabilitation professionals can support adults regaining and continuing to build self-confidence, aiming for the perfect balance between blood pressure regulation, quality of life, and being physically active. Implications for rehabilitation Rehabilitation professionals should support regaining and continuing to build self-confidence related to being physically active in adults with type B aortic dissection in the early stages of recovery and beyond. Adults with an uncomplicated type B aortic dissection want rehabilitation professionals to tell them primarily what is possible (recommendations) rather than what is not allowed (rules). Rehabilitation professionals should help adults with an uncomplicated type B aortic dissection to explore, push and, ultimately, accept limits related to exercise tolerance.

Renal autocrine neuropeptide FF (NPFF) signaling regulates blood pressure

The kidney and brain play critical roles in the regulation of blood pressure. Neuropeptide FF (NPFF), originally isolated from the bovine brain, has been suggested to contribute to the pathogenesis of hypertension. However, the roles of NPFF and its receptors, NPFF-R1 and NPFF-R2, in the regulation of blood pressure, via the kidney, are not known. In this study, we found that the transcripts and proteins of NPFF and its receptors, NPFF-R1 and NPFF-R2, were expressed in mouse and human renal proximal tubules (RPTs). In mouse RPT cells (RPTCs), NPFF, but not RF-amide-related peptide-2 (RFRP-2), decreased the forskolin-stimulated cAMP production in a concentration- and time-dependent manner. Furthermore, dopamine D1-like receptors colocalized and co-immunoprecipitated with NPFF-R1 and NPFF-R2 in human RPTCs. The increase in cAMP production in human RPTCs caused by fenoldopam, a D1-like receptor agonist, was attenuated by NPFF, indicating an antagonistic interaction between NPFF and D1-like receptors. The renal subcapsular infusion of NPFF in C57BL/6 mice decreased renal sodium excretion and increased blood pressure. The NPFF-mediated increase in blood pressure was prevented by RF-9, an antagonist of NPFF receptors. Taken together, our findings suggest that autocrine NPFF and its receptors in the kidney regulate blood pressure, but the mechanisms remain to be determined.

Examination of role of the AMP-activated protein kinase (Ampk) signaling pathway during low salinity adaptation in the mud crab, Scylla paramamosain, with reference to glucolipid metabolism

It is known that the marine euryhaline crab, mud crab (Scylla paramamosain), is capable of adapting to low salinity conditions through an innate osmoregulatory system. However, the influence of nutritional conditions during low salinity adaptation has not been fully elucidated. In this study, transcriptome analysis was employed to examine whether low salinity affects the AMP-activated protein kinase (Ampk) signaling pathway, and thereby carbohydrate and lipid metabolism. Further analysis revealed that low salinity activated the expression of P-Ampk and promoted glycolysis and lipolysis, which enhances glycogen and lipid utilization. Nutritional deprivation confirmed that nutrients influenced the survival and osmotic pressure regulation of mud crab under to low salinity via the Ampk signaling pathway. During adaptation to low salinity, carbohydrates were the primary energy source in the initial 7 days, followed by lipids. Further investigation showed that pharmacological stimulation of mechanistic targets in the Ampk signaling pathway using metformin could promote the osmotic pressure regulation of mud crab, confirmed the pivotal role of this pathway in low salinity adaptation. Overall, the present study demonstrated that nutrition, metabolism and osmotic pressure regulation interactively contribute to salinity adaptation in mud crab. Specifically, low salinity induced remodeling of nutritional metabolism homeostasis and promoted glycolipid catabolism, thereby providing energy for osmotic pressure regulation in mud crabs.

Nursing interventions to prevent pressure injury among open heart surgery patients: A systematic review.

Nurses are vital in identifying and preventive pressure injuries (PIs) in hospitalized patients undergoing open heart surgery. Interventions to prevent PIs are crucial for every critical patient, and it's essential to recognize that preventing PIs involves a complex intervention. To examine the nursing interventions for the prevention of PI in patients with open heart surgery. A systematic review study. Web of Science, Science Direct, PubMed, Scopus, MEDLINE Ultimate, CINAHL Ultimate, ULAKBIM, Cochrane Library, Google Scholar and university library databases were scanned. The initial search performed in the databases was updated on 4 February 2023, and on 7 April 2024, for potential publications included in that period. Data between February 2013 and April 2024 were scanned. The databases were searched with the keywords 'pressure injury', 'nursing interventions' and 'open heart surgery'. The systematic compilation process was carried out in accordance with the guidelines in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guide. Seventeen studies were examined using nursing interventions that applied to the selected study population. Care packages included an inflatable head pad, a pressure sensor mattress cover, multi-layer silicone foam, pressure-reducing coatings, endotracheal tube (ETT) repositioning and cuff pressure regulation. Interventions to reduce PI in open heart surgery patients are applied in the preadmission, perioperative and postoperative periods. It was concluded that care packages, inflatable head pads, pressure sensor bedspreads, multi-layered silicone foam, pressure-reducing covers, ETT repositioning and cuff pressure regulation were effective in all nursing interventions. The strength of the available evidence was rated from strong to weak. These findings reveal an efficient combination of multi-component nursing interventions for preventing PIs in planning patient care in the intensive care. The interventions that are used throughout the patient's entire care process are crucial for the prevention of PIs.

Examination of role of the AMP-activated protein kinase (Ampk) signaling pathway during low salinity adaptation in the mud crab, Scylla paramamosain, with reference to glucolipid metabolism

It is known that the marine euryhaline crab, mud crab (Scylla paramamosain), is capable of adapting to low salinity conditions through an innate osmoregulatory system. However, the influence of nutritional conditions during low salinity adaptation has not been fully elucidated. In this study, transcriptome analysis was employed to examine whether low salinity affects the AMP-activated protein kinase (Ampk) signaling pathway, and thereby carbohydrate and lipid metabolism. Further analysis revealed that low salinity activated the expression of P-Ampk and promoted glycolysis and lipolysis, which enhances glycogen and lipid utilization. Nutritional deprivation confirmed that nutrients influenced the survival and osmotic pressure regulation of mud crab under to low salinity via the Ampk signaling pathway. During adaptation to low salinity, carbohydrates were the primary energy source in the initial 7 days, followed by lipids. Further investigation showed that pharmacological stimulation of mechanistic targets in the Ampk signaling pathway using metformin could promote the osmotic pressure regulation of mud crab, confirmed the pivotal role of this pathway in low salinity adaptation. Overall, the present study demonstrated that nutrition, metabolism and osmotic pressure regulation interactively contribute to salinity adaptation in mud crab. Specifically, low salinity induced remodeling of nutritional metabolism homeostasis and promoted glycolipid catabolism, thereby providing energy for osmotic pressure regulation in mud crabs.

Renal denervation: a key approach to hypertension and cardiovascular disease.

Sympathetic activation plays a critical role in the development of hypertension and cardiovascular disease, including heart failure and arrhythmias. Renal nerves contribute to the regulation of blood pressure and fluid volume through renal sympathetic efferent nerves, and to the modulation of sympathetic outflow through renal sensory afferent nerves. Previous studies including ours suggest that selective afferent renal denervation with preservation of efferent renal nerves can significantly decrease central sympathetic outflow in animal models of hypertension with renal damage. In Dahl salt-sensitive rats fed high salt diet from an early age, a model of hypertensive heart failure, this central sympathoinhibition by afferent renal denervation may attenuate the development of heart failure without significant blood pressure reduction. Accumulating clinical evidence supports the efficacy of renal denervation as an antihypertensive treatment. However, it remains important to clarify the appropriate indications and predictors of responders to renal denervation in the treatment of hypertension. Several clinical studies suggest beneficial effects of renal denervation in patients with heart disease, with or without hypertension, although most were not sham-controlled. In particular, some clinical studies have demonstrated that renal denervation reduces the incidence of atrial fibrillation or cardiovascular events even without a significant antihypertensive effect. It is essential to accumulate more insightful data in patients undergoing renal denervation, to establish the efficacy of renal denervation in patients with cardiovascular disease in the clinical setting, and to elucidate the therapeutic mechanisms of renal denervation and the renal nerves-linked pathophysiology of cardiovascular disease in basic research. This review outlines the effects of renal denervation on sympathetic activity and organ damage in animal models of hypertension and hypertensive heart failure, including our own data. Beyond the antihypertensive effects, the beneficial effects of renal denervation on cardiovascular disease are also discussed based on clinical studies. Several animal and clinical studies suggest the cardioprotective effects of renal denervation even in the absence of significant blood pressure reduction, probably due to its sympathoinhibitory effects.

G protein-coupled receptor kinases in hypertension: physiology, pathogenesis, and therapeutic targets.

G protein-coupled receptors (GPCRs) mediate cellular responses to a myriad of hormones and neurotransmitters that play vital roles in the regulation of physiological processes such as blood pressure. In organs such as the artery and kidney, hormones or neurotransmitters, such as angiotensin II (Ang II), dopamine, epinephrine, and norepinephrine exert their functions via their receptors, with the ultimate effect of keeping normal vascular reactivity, normal body sodium, and normal blood pressure. GPCR kinases (GRKs) exert their biological functions, by mediating the regulation of agonist-occupied GPCRs, non-GPCRs, or non-receptor substrates. In particular, increasing number of studies show that aberrant expression and activity of GRKs in the cardiovascular system and kidney inhibit or stimulate GPCRs (e.g., dopamine receptors, Ang II receptors, and α- and β-adrenergic receptors), resulting in hypertension. Current studies focus on the effect of selective GRK inhibitors in cardiovascular diseases, including hypertension. Moreover, genetic studies show that GRK gene variants are associated with essential hypertension, blood pressure response to antihypertensive medicines, and adverse cardiovascular outcomes of antihypertensive treatment. In this review, we present a comprehensive overview of GRK-mediated regulation of blood pressure, role of GRKs in the pathogenesis of hypertension, and highlight potential strategies for the treatment of hypertension. Schematic representation of GPCR desensitization process. Activation of GPCRs begins with the binding of an agonist to its corresponding receptor. Then G proteins activate downstream effectors that are mediated by various signaling pathways. GPCR signaling is halted by GRK-mediated receptor phosphorylation, which causes receptor internalization through β-arrestin.

Cardiomyocyte PANX1 Controls Glycolysis and Neutrophil Recruitment in Hypertrophy.

PANX1 (pannexin 1), a ubiquitously expressed ATP release membrane channel, has been shown to play a role in inflammation, blood pressure regulation, and myocardial infarction. However, the possible role of PANX1 in cardiomyocytes in the progression of heart failure has not yet been investigated. We generated a novel mouse line with constitutive deletion of PANX1 in cardiomyocytes (Panx1MyHC6). PANX1 deletion in cardiomyocytes had no effect on unstressed heart function but increased the glycolytic metabolism and resulting glycolytic ATP production, with a concurrent decrease in oxidative phosphorylation, both in vivo and in vitro. In vitro, treatment of H9c2 cardiomyocytes with isoproterenol led to PANX1-dependent release of ATP and Yo-Pro-1 uptake, as assessed by pharmacological blockade with spironolactone and siRNA-mediated knockdown of PANX1. To investigate nonischemic heart failure and the preceding cardiac hypertrophy, we administered isoproterenol, and we demonstrated that Panx1MyHC6 mice were protected from systolic and diastolic left ventricle volume increases as a result of cardiomyocyte hypertrophy. Moreover, we found that Panx1MyHC6 mice showed decreased isoproterenol-induced recruitment of immune cells (CD45+), particularly neutrophils (CD11b+, Ly6g+), to the myocardium. Together, these data demonstrate that PANX1 deficiency in cardiomyocytes increases glycolytic metabolism and protects against cardiac hypertrophy in nonischemic heart failure at least in part by reducing immune cell recruitment. Our study implies PANX1 channel inhibition as a therapeutic approach to ameliorate cardiac dysfunction in patients with heart failure.

Shear wave elastography of transverse carpal ligament increased with simulated carpal tunnel pressure

BackgroundElevation of carpal tunnel pressure is known to be associated with carpal tunnel syndrome. This study aimed to correlate the shear wave elastography in the transverse carpal ligament (TCL) with carpal tunnel pressures using a cadaveric model.MethodsEight human cadaveric hands were dissected to evacuate the tunnels. A medical balloon was inserted into each tunnel and connected to a pressure regulator to simulate tunnel pressure in the range of 0-210 mmHg with an increment of 30 mmHg. Shear wave velocity and modulus was measure in the middle of TCL.ResultsSWV and SWE were significantly dependent on the pressure levels (p < 0.001), and positively correlated to the tunnel pressure (SWV: R = 0.997, p < 0.001; SWE: R = 0.996, p < 0.001). Regression analyses showed linear relationship SWV and pressure (SWV = 4.359 + 0.0263 * Pressure, R2 = 0.994) and between SWE and pressure (SWE = 48.927 + 1.248 * Pressure, R2 = 0.996).ConclusionThe study indicated that SWV and SWE in the TCL increased linearly as the tunnel pressure increased within the current pressure range. The findings suggested that SWV/SWE in the TCL has the potential for prediction of tunnel pressure and diagnosis of carpal tunnel syndrome.

Analysis of methods of natural gas technical loss determination and technical loss norms in gas supply network

In modern times, the role of energy resources is very large. One of the important energy resources is natural gas. The biggest advantage of using natural gas as a fuel is its high heat capacity and complete combustion without the formation of harmful substances. The process of natural gas distribution in the gas supply network is observed with gas loss. This is an objective, natural situation and creates a number of difficulties for natural gas enterprises. The article focuses on gas consumption in technological processes in the gas supply network, gas purges from pipelines during pipeline repair works, gas flushing out from the pipeline and determination of gas technological losses during the removal of air from the pipeline. Determination of gas losses caused by non-hermeticity of external gas pipelines and equipment, gas pressure regulation station (GPRS), cabinet-type gas control points (GCP), universal pressure regulator (UPR) and gas losses occurring during repairing of other technological equipment are discussed. Also, the determination of technical losses of natural gas at meters, sampling nodes, safety valves, gas distribution stations (GDS) (from gas losses during the management of shut-off valves, during purge of process instrumentation and automatics, when taking gas samples, during purges proses of safety valves, apparatus and pulse lines) is discussed. The article describes the principle of formation of technical losses in the gas supply network. Technical loss sources of natural gas in the process of gas supply, methods of calculating loss norms, the amount of small loss of which is determined separately for each specified loss source, are mentioned. Keywords: gas supply; natural gas; technical losses; pipeline; GPRS; GCP; UPR; gas meters; safety valves; gas distribution station.

How do underwriting and investment activities affect P&amp;C insurers’ capital adjustments? Evidence from Canada

AbstractUsing a sample of 83 Canadian property-casualty insurance companies from 1996 to 2010, we examine the impact of underwriting and investment choices on the insurers’ capital level and adjustment speed. An aggressive investment policy (risky equity investments) and a heavy reliance on reinsurance underwriting activities have the opposite effect on insurers’ capital level, though both lead to a slower capital adjustment speed. Meanwhile, insurers reshuffling their underwriting and investments significantly change their capital. With an integrated framework that considers underwriting cycles and regulatory pressure, insurers are slower in their capital adjustments in hard markets of the underwriting cycle, and higher regulatory pressure for an insurer moderates the positive relationship between capital level and adjustment speed.

Renal denervation for resistant hypertension in an elderly patient despite quintuple antihypertensive therapy: a case report

Hypertension is the leading cause of cardiovascular morbidity and mortality. Renal nerves have critical roles in the regulation of blood pressure and fluid volume, and their dysfunction is closely associated with cardiovascular diseases. The denervation procedure is performed through a renal ablation catheter and has been shown in recent trials to provide impressive blood pressure reductions and a favorable safety profile in drug-resistant hypertension. We present a 78-year-old patient who underwent renal denervation due to unresponse to quintuple antihypertensive treatment.

Trends in Corporate Environmental Compliance Research: A Bibliometric Analysis (2004–2024)

Against the backdrop of the global energy crisis and climate change, corporate environmental compliance has emerged as a key aspect of environmental regulation and a focal point of academic interest. It plays a crucial role in alleviating regulatory pressure, enabling green innovations, enhancing performance, and fostering sustainable development. Despite extensive research in the field, comprehensive reviews and bibliometric analyses remain scarce. To address this gap, this study meticulously analyzed 851 papers indexed in the WoS’s SSCI and SCI from 2004 to 2024. Using visualization tools like VOSviewer and CiteSpace, it conducted a multidimensional bibliometric analysis and systematic review, identifying core authors such as Aseem, Ntim, and Zeng, high-productivity countries including China, the USA, and the UK, and key journals like the Journal of Cleaner Production and Sustainability. Keyword co-occurrence and cluster analysis revealed central research themes of environmental information disclosure, innovation, and environmental management systems. Burst analysis highlighted emerging hot topics, notably ecological and green innovation, and the interplay between Total Factor Productivity and environmental regulations. Additionally, we identified several critical gaps in the field. For instance, research on corporate environmental governance mechanisms in the context of digital transformation remains insufficient. Furthermore, the effectiveness of multi-stakeholder collaborative governance frameworks requires ongoing investigation. Therefore, we encourage future researchers to focus on the following topics: digitization and environmental compliance, multi-stakeholder participation mechanisms, cost–benefit analysis of corporate environmental compliance, and the impact of political and regulatory environments on corporate environmental compliance.

Urinary hyaluronidase activity is closely related to vasopressinergic system following an oral water load in men: a potential role in blood pressure regulation and early stages of hypertension development.

Blood pressure (BP) regulation is a complex process involving several factors, among which water-sodium balance holds a prominent place. Arginin-vasopressin (AVP), a key player in water metabolism, has been evoked in hypertension development since the 1980s, but, to date, the matter is still controversial. Hyaluronic acid metabolism has been reported to be involved in renal water management, and AVP appears to increase hyaluronidase activity resulting in decreased high-molecular-weight hyaluronan content in the renal interstitium, facilitating water reabsorption in collecting ducts. Hence, our aim was to evaluate urinary hyaluronidase activity in response to an oral water load in hypertensive patients (HT, n=21) compared to normotensive subjects with (NT+, n=36) and without (NT-, n=29) a family history of hypertension, and to study its association with BP and AVP system activation, expressed by serum copeptin levels and urine Aquaporin 2 (AQP2)/creatinine ratio. Eighty-six Caucasian men were studied. Water load test consisted in oral administration of 15-20 ml of water/kg body weight over 40-45 min. BP, heart rate, serum copeptin, urine hyaluronidase activity and AQP2 were monitored for 4 hours. In response to water drinking, BP raised in all groups with a peak at 20-40 min. Baseline levels of serum copeptin, urinary hyaluronidase activity and AQP2/creatinine ratio were similar among groups and all decreased after water load, reaching their nadir at 120min and then gradually recovering to baseline values. Significantly, a blunted reduction in serum copeptin, urinary hyaluronidase activity and AQP2/creatinine ratio was observed in NT+ compared to NT- subjects. A strong positive correlation was also found between urinary hyaluronidase activity and AQP2/creatinine ratio, and, although limited to the NT- group, both parameters were positively associated with systolic BP. Our results demonstrate for the first time the existence in men of a close association between urinary hyaluronidase activity and vasopressinergic system and suggest that NT+ subjects have a reduced ability to respond to water loading possibly contributing to the blood volume expansion involved in early-stage hypertension. Considering these data, AVP could play a central role in BP regulation by affecting water metabolism through both hyaluronidase activity and AQP2 channel expression.

Increased daytime and awakening salivary free aldosterone in essential hypertensive men.

While aldosterone plays an important role in blood pressure regulation, its role in essential hypertension (EHT) remains unclear. Here, we systematically investigated the secretion of biologically-active free aldosterone in saliva in response to awakening (AldAR) and during the day (AldDay) in EHT compared to normotensive controls (NT). In 30 men with EHT and 30 age-matched NT, AldAR saliva samples were collected immediately after awakening and 15, 30, 45, and 60 min thereafter and AldDay samples were collected from 08:30-22:00 h on two consecutive days. Over the course of the day, men with EHT had higher repeated AldDay levels compared to NT (p = .002) with higher concentrations in the morning hours (p's ≤ .047), a steeper decline over the course of the day (p's ≤ .018), and similar concentrations in the evening (p's ≥ .21). Regarding AldAR, we observed higher concentrations in EHT at awakening (p = .017) and borderline higher concentrations at 15 min (p = .086). No differences were found 30-60 min after awakening (p's ≥ .34). Analyses with repeated and aggregated AldAR levels resulted in borderline significantly higher free aldosterone in EHT (p's ≤ .077). Complementary analyses confirmed linear associations between higher blood pressure and higher AldAR and AldDay levels. Our data point to elevated salivary free aldosterone secretion in EHT over the course of the day, particularly in the morning hours. As the free aldosterone fraction is considered biologically active, our data may point to a biological mechanism underlying EHT.