Bradykinin Levels Research Articles

RhoA/ROK and NO contribute to vascular hyporeactivity in endotoxaemic rats

Hypotension and vascular hyporeactivity are significant characteristics of septic shock. The RhoA/Rho-kinase (RhoA/ROK) pathway is a major target for regulating calcium sensitivity of agonist-induced contraction. Here, we investigated the role of RhoA/ROK pathway in vascular hyporeactivity in endotoxaemic animals. Male Wistar rats were intravenously infused with E. coli lipopolysaccharide (LPS, 10 mg/kg) to induce endotoxaemia. Experimental animals were assigned to five groups: (i) 6 h after saline (Control); (ii) 1 h after LPS (LPS1h); (iii) 2 h after LPS (LPS2h); (iv) 4 h after LPS (LPS4h); (v) 6 h after LPS (LPS6h). LPS1h and LPS2h were regarded as early endotoxaemia, whereas LPS4h and LPS6h were regarded as late endotoxaemia. Results showed that LPS induced a biphasic hypotension and sustained vascular hyporeactivity in vivo, and this hyporeactivity only occurred in late endotoxaemia ex vivo. Meanwhile, the aortic inducible nitric oxide (NO) synthase expression and the serum NO level were time-dependently increased after LPS. However, the aortic RhoA activity and myosin phosphatase targeting subunit 1 phosphorylation were increased in early endotoxaemia and this vascular reactivity was inhibited by ROK inhibitor, Y27632. In addition, the plasma bradykinin level was increased at 15 min and aortic endothelial NO synthase expression was increased 1 h after LPS. In conclusion, an increased RhoA activity may compensate vascular hyporeactivity in early endotoxaemia, whereas in late endotoxaemia, the large amount of NO produced causes inhibition of RhoA activity leading to vascular hyporeactivity in vivo and ex vivo.

Modulation Of Sympathetic Nervous, Renin Angiotensin And Kallikrein Kinin Systems On Youth Obesity

The aim of this study was to evaluate the relationship between obesity and Sympathetic Nervous (SNS), Renin Angiotensin (RAS) and Kallikrein Kinin (KKS) Systems. Subjects were divided in groups: 43 normal weight (NW), 14 overweight (OV), 37 obese (OB) and 10 MO (MO). The Ang I, Ang II, Ang‐(1–7), Bradykinin (BK), Vasopressin (VP), norepinephrine (NE), epinephrine (EP), serotonin (SE) plasmatic levels had been measured by HPLC. Ang (1–7) levels were lower in MO and OB compared with NW (0.06±0.04; 0.24±0.17 and 0.52±0.21nmol/mL). Ang I levels were higher in MO compared with NW (0.06±0.03; 0.03±0.02). OB had higher values of VP than NW (0.107±0.0217; 0.087±0.016ng/mL). OB had higher values of EP and NE than NW (48.3±20.3 vs 34.7±17.2 and 85.6±27.9 vs 45.9±28.3 pg/mL respectively). The NW had higher concentration of SE than the OV (281.2±113.0 vs 200.1±117.1 ng/mL). MO had lower BK levels than NW (0.367 vs 0.885). Our results showed a reduction of Ang (1–7) and increased of Ang I associated with weight gain in adolescents suggesting a modulation of ACE2 and NEP. According to our results, obesity in youth seems to be related with high levels of EP, NE, blood pressure and low Ang (1–7). These alterations in the SNS, RAS and KKS, associated with low levels of Ang 1–7 and BK may contribute to the development of hypertension in obese adolescents, since these can resulting in cardiovascular target organ damage such as the heart, the vascular wall and the kidney.

Antioxidant activity of peptide-based angiotensin converting enzyme inhibitors

Angiotensin converting enzyme (ACE) inhibitors are important for the treatment of hypertension as they can decrease the formation of vasopressor hormone angiotensin II (Ang II) and elevate the levels of vasodilating hormone bradykinin. It is observed that bradykinin contains a Ser-Pro-Phe motif near the site of hydrolysis. The selenium analogues of captopril represent a novel class of ACE inhibitors as they also exhibit significant antioxidant activity. In this study, several di- and tripeptides containing selenocysteine and cysteine residues at the N-terminal were synthesized. Hydrolysis of angiotensin I (Ang I) to Ang II by ACE was studied in the presence of these peptides. It is observed that the introduction of L-Phe to Sec-Pro and Cys-Pro peptides significantly increases the ACE inhibitory activity. On the other hand, the introduction of L-Val or L-Ala decreases the inhibitory potency of the parent compounds. The presence of an L-Pro moiety in captopril analogues appears to be important for ACE inhibition as the replacement of L-Pro by L-piperidine 2-carboxylic acid decreases the ACE inhibition. The synthetic peptides were also tested for their ability to scavenge peroxynitrite (PN) and to exhibit glutathione peroxidase (GPx)-like activity. All the selenium-containing peptides exhibited good PN-scavenging and GPx activities.

Prospective, double-blind, placebo-controlled trials of ecallantide for acute attacks of hereditary angioedema

Hereditary angioedema (HAE) is a rare genetic disorder characterized by unpredictable, episodic, incapacitating attacks of well-demarcated angioedema in the absence of urticaria and pruritus. HAE is due to deficient or dysfunctional C1-esterase inhibitor activity, which results in unopposed activation of plasma kallikrein, resulting in increased levels of bradykinin. Ecallantide is a potent and specific plasma kallikrein inhibitor approved for the treatment of acute attacks of HAE affecting any anatomic site. In Phase III clinical trials, subcutaneously administered ecallantide demonstrated significant, rapid and durable symptom relief. Ecallantide was effective for all attack types, including potentially life-threatening laryngeal attacks. The main safety concern is potentially serious hypersensitivity reactions, including anaphylaxis. Ecallantide represents an important treatment option for the management of acute attacks of HAE.

HPLC and MALDI investigation of the stress influence on the composition of skin secretion of the Common frog Rana temporaria

Skin secretory amphibian antimicrobial peptides are the part of their immune defense. The present work is devoted to the study of the influence of “water environment stress” and additional bacterial impact on the composition of the skin secretion of the Common frog (Rana temporaria) by means of high-performance liquid chromatography (HPLC) and matrix assisted laser desorption/ionization (MALDI) mass spectrometry. It was shown that the contact of the amphibian species with Micrococcus luteus and Staphylococcus aureus stimulates the release of antimicrobial peptides, maintains the high bradykinin and related peptides levels in the skin secretion and influences the processing of the latter ones. The possibilities of mass spectrometric profiling by using HPLC and MALDI were demonstrated. This feature allows the detection of potentially bioactive peptides for their future direct testing, as has been shown for temporin M and brevinin 1Tb in the present study.

Hereditary angioedema: Classification, pathogenesis, and diagnosis

Hereditary angioedema (HAE) is a rare autosomal dominant genetic disorder associated with a deficiency in C1 inhibitor. More than 200 mutations in this gene, located on chromosome 11, have been identified. Although HAE is often inherited, 20-25% of cases are from new spontaneous mutations and they have no family history of swelling. Decreased C1 inhibitor activity leads to inappropriate activation of multiple pathways, including the complement and contact systems and the fibrinolysis and coagulation systems. Reduced C1 inhibitor activity results in increased activation of plasma kallikrein-kinin system proteases and increased bradykinin levels. Bradykinin is felt to be the main mediator of symptoms in HAE. Patients with HAE have recurrent episodes of swelling of the extremities, abdomen, face, and upper airway. Angioedema involving the gastrointestinal tract can lead to intestinal wall edema, which results in abdominal pain, nausea, vomiting, and diarrhea. Laryngeal swelling is life-threatening and may lead to asphyxia. Common triggers of an attack include trauma, stress, infection, menstruation, oral contraceptives, hormone replacement therapy, and angiotensin-converting enzyme inhibitors. Laboratory testing including C4, C1 inhibitor level, and function is needed to confirm or rule out the diagnosis of HAE. The treatment of HAE has improved significantly in recent years with the availability of several safe and effective therapies. Several consensus guidelines have been created to further assist in the management of HAE patients. This review will provide an update on the classification, pathophysiology, clinical presentation, and diagnosis of HAE.

Pathophysiology of Hereditary Angioedema

Laryngeal angioedema may be associated with significant morbidity and even mortality. Because of the potential severity of attacks, both allergists and otolaryngologists must be knowledgeable about the recognition and treatment of laryngeal angioedema. This study describes the clinical characteristics and pathophysiology of bradykinin-mediated angioedema. A literature review was conducted concerning the clinical characteristics and pathophysiology of types I and II hereditary angioedema (HAE), type III HAE, acquired C1 inhibitor (C1INH) deficiency, and angiotensin-converting enzyme (ACE) inhibitor-associated angioedema. The diagnosis of type I/II HAE is relatively straightforward as long as the clinician maintains a high index of suspicion. Mutations in the SERPING1 gene result in decreased secretion of functional C1INH and episodic activation of plasma kallikrein and Hageman factor (FXII) of the plasma contact system with cleavage of high molecular weight kininogen and generation of bradykinin. In contrast, there are no unequivocal criteria for making a diagnosis of type III HAE, although a minority of these patients may have a mutation in the factor XII gene. Angioedema attacks and mediator of swelling in acquired C1INH deficiency are similar to those in type I or II HAE; however, it occurs on a sporadic basis because of excessive consumption of C1INH in patients who are middle aged or older. ACE inhibitor-associated angioedema should always be considered in any patient taking an ACE inhibitor who experiences angioedema. ACE is a kininase, which when inhibited is thought to result in increased bradykinin levels. Bradykinin acts on vascular endothelial cells to enhance vascular permeability. Laryngeal swelling is not infrequently encountered in bradykinin-mediated angioedema. Novel therapies are becoming available that for the first time provide effective treatment for bradykinin-mediated angioedema. Because the characteristics and treatment of these angioedemas are quite distinct from each other and from histamine-mediated angioedema, it is crucial that the physician be able to recognize and distinguish these swelling disorders.

Activation of the Hemostatic System During Cardiopulmonary Bypass

Cardiopulmonary bypass (CPB) is a unique clinical scenario that results in widespread activation of the hemostatic system. However, surgery also results in normal increases in coagulation activation, platelet activation, and fibrinolysis that are associated with normal wound hemostasis. Conventional CPB interferes with normal hemostasis by diluting hemostatic cells and proteins, through reinfusion of shed blood, and through activation on the bypass circuit surface of multiple systems including platelets, the kallikrein-kinin system, and fibrinolysis. CPB activation of the kallikrein-kinin system increases activated factor XIIa, kallikrein, bradykinin, and tissue plasminogen activator levels, but has little effect on thrombin generation. Increased tissue plasminogen activator and circulating fibrin result in increased plasmin generation, which removes hemostatic fibrin. The nonendothelial surface of the bypass circuit, along with circulating thrombin and plasmin, lead to platelet activation, platelet receptor loss, and reduced platelet response to wounds. In this review, we highlight the major mechanisms responsible for CPB-induced activation of the hemostatic system and examine some of the markers described in the literature. Additionally, strategies used to reduce this activation are discussed, including limiting cardiotomy suction, increasing circuit biocompatibility, antithrombin supplementation, and antifibrinolytic use. Determining which patients will most benefit from specific therapies will ultimately require investigation into genetic phenotypes of coagulation protein expression. Until that time, however, a combination of approaches to reduce the hemostatic activation from CPB seems warranted.

Aliskiren increases bradykinin and tissue kallikrein mRNA levels in the heart

1. Aliskiren is a renin inhibitor with an IC(50) of 0.6 nmol/L for human renin, 4.5 nmol/L for mouse renin and 80 nmol/L for rat renin. 2. In the present study, we compared the effects of aliskiren (10 mg/kg per day), the angiotensin-converting enzyme inhibitor perindopril (0.2 mg/kg per day) and their combination on angiotensin and bradykinin peptides in female heterozygous (mRen-2)27 rats, transgenic for the mouse renin gene. 3. All three treatments produced similar reductions in systolic blood pressure, heart weight and plasma aldosterone levels and reduced angiotensin II levels in lung, but only perindopril and the combination reduced angiotensin II levels in kidney of (mRen-2)27 rats. In contrast, aliskiren and the combination, but not perindopril alone, increased cardiac bradykinin levels. Aliskiren increased immunostaining for tissue kallikrein in the heart and reduced cardiac fibrosis. 4. We investigated the mechanism underlying the increase in bradykinin levels following aliskiren treatment in Sprague-Dawley rats, in which aliskiren has a lower potency for renin inhibition. Aliskiren (10 mg/kg per day) reduced renal angiotensin levels within 24 h, but treatment for > 24 h was required to increase cardiac bradykinin levels. Moreover, 3 mg/kg per day aliskiren increased cardiac bradykinin levels, but did not reduce renal angiotensin levels. Aliskiren did not potentiate the hypotensive effects of bradykinin; however, it increased tissue kallikrein, but not plasma kallikrein, mRNA levels in the heart. 5. These data demonstrate that the aliskiren-induced increase in cardiac bradykinin levels is independent of renin inhibition and changes in bradykinin metabolism, but is associated with increased tissue kallikrein gene expression.

Going in deeper and deeper: signal transduction pathways in myofacial trigger points – A narrative review

AbstractObjectiveDiscuss recent cytokine findings in myofascial trigger points (MTrPs) in the context of known kinase cascades and other transduction pathways to determine what pharmacological and/or other manual therapy strategies might be useful to treat myofascial pain, and identify key biochemical entities to target future research.MethodsSearch of the PubMed, Scopus, and Google databases for relevant key studies published since 1980 in English and German languages.ResultsOne hundred and thirteen articles were identified for inclusion into this narrative review.DiscussionRecent biochemical findings indicate a significant decrease in pH in active MTrPs compared to latent MTrPs or normal muscle, and large significant increases in cytokines, catecholamines, and neurotransmitters. The findings support Simons’ hypothesis, and it is possible that changes in bradykinin levels might in part be responsible for the pain experienced by patients with active MTrPs. There is also sufficient evidence to suggest that...

The ACE Gene and Human Performance

Some 12 years ago, a polymorphism of the angiotensin I-converting enzyme (ACE) gene became the first genetic element shown to impact substantially on human physical performance. The renin-angiotensin system (RAS) exists not just as an endocrine regulator, but also within local tissue and cells, where it serves a variety of functions. Functional genetic polymorphic variants have been identified for most components of RAS, of which the best known and studied is a polymorphism of the ACE gene. The ACE insertion/deletion (I/D) polymorphism has been associated with improvements in performance and exercise duration in a variety of populations. The I allele has been consistently demonstrated to be associated with endurance-orientated events, notably, in triathlons. Meanwhile, the D allele is associated with strength- and power-orientated performance, and has been found in significant excess among elite swimmers. Exceptions to these associations do exist, and are discussed. In theory, associations with ACE genotype may be due to functional variants in nearby loci, and/or related genetic polymorphism such as the angiotensin receptor, growth hormone and bradykinin genes. Studies of growth hormone gene variants have not shown significant associations with performance in studies involving both triathletes and military recruits. The angiotensin type-1 receptor has two functional polymorphisms that have not been shown to be associated with performance, although studies of hypoxic ascent have yielded conflicting results. ACE genotype influences bradykinin levels, and a common gene variant in the bradykinin 2 receptor exists. The high kinin activity haplotye has been associated with increased endurance performance at an Olympic level, and similar results of metabolic efficiency have been demonstrated in triathletes. Whilst the ACE genotype is associated with overall performance ability, at a single organ level, the ACE genotype and related polymorphism have significant associations. In cardiac muscle, ACE genotype has associations with left ventricular mass changes in response to stimulus, in both the health and diseased states. The D allele is associated with an exaggerated response to training, and the I allele with the lowest cardiac growth response. In light of the I-allele association with endurance performance, it seems likely that other regulatory mechanisms exist. Similarly in skeletal muscle, the D allele is associated with greater strength gains in response to training, in both healthy individuals and chronic disease states. As in overall performance, those genetic polymorphisms related to the ACE genotype, such as the bradykinin 2 gene, also influence skeletal muscle strength. Finally, the ACE genotype may influence metabolic efficiency, and elite mountaineers have demonstrated an excess of I alleles and I/I genotype frequency in comparison to controls. Interestingly, this was not seen in amateur climbers. Corroboratory evidence exists among high-altitude settlements in both South America and India, where the I allele exists in greater frequency in those who migrated from the lowlands. Unfortunately, if the ACE genotype does influence metabolic efficiency, associations with peak maximal oxygen consumption have yet to be rigorously demonstrated. The ACE genotype is an important but single factor in the determinant of sporting phenotype. Much of the mechanisms underlying this remain unexplored despite 12 years of research.

A single nucleotide deletion at the C1 inhibitor gene as the cause of hereditary angioedema: insights from a Brazilian family

Hereditary angioedema is an autosomal dominant disease characterized by episodes of subcutaneous and submucosal edema. It is caused by deficiency of the C1 inhibitor protein, leading to elevated levels of bradykinin. More than 200 mutations in C1 inhibitor gene have been reported. The aim of this study was to analyze clinical features of a large family with an index case of hereditary angioedema and to determine the disease-causing mutation in this family. Family pedigree was constructed with 275 individuals distributed in five generations. One hundred and sixty-five subjects were interviewed and investigated for mutation at the C1 inhibitor gene. Subjects reporting a history of recurrent episodes of angioedema and/or abdominal pain attacks underwent evaluation for hereditary angioedema. We have identified a novel mutation at the C1 inhibitor gene, c.351delC, which is a single-nucleotide deletion of a cytosine on exon 3, resulting in frameshift with premature stop codon. Sequencing analysis of the hypothetical truncated C1 inhibitor protein allowed us to conclude that, if transcription occurs, this protein has no biological activity. Twenty-eight members of the family fulfilled diagnostic criteria for hereditary angioedema and all of them presented the c.351delC mutation. Variation in clinical presentation and severity of disease was observed among these patients. One hundred and thirty-seven subjects without hereditary angioedema did not have the c.351delC mutation. The present study provides definitive evidence to link a novel genetic mutation to the development of hereditary angioedema in patients from a Brazilian family.

Cleavage of Kininogen and Subsequent Bradykinin Release by the Complement Component: Mannose-Binding Lectin-Associated Serine Protease (MASP)-1

Bradykinin (BK), generated from high-molecular-weight kininogen (HK) is the major mediator of swelling attacks in hereditary angioedema (HAE), a disease associated with C1-inhibitor deficiency. Plasma kallikrein, activated by factor XIIa, is responsible for most of HK cleavage. However other proteases, which activate during episodes of angioedema, might also contribute to BK production. The lectin pathway of the complement system activates after infection and oxidative stress on endothelial cells generating active serine proteases: MASP-1 and MASP-2. Our aim was to study whether activated MASPs are able to digest HK to release BK. Initially we were trying to find potential new substrates of MASP-1 in human plasma by differential gel electrophoresis, and we identified kininogen cleavage products by this proteomic approach. As a control, MASP-2 was included in the study in addition to MASP-1 and kallikrein. The proteolytic cleavage of HK by MASPs was followed by SDS-PAGE, and BK release was detected by HPLC. We showed that MASP-1 was able to cleave HK resulting in BK production. MASP-2 could also cleave HK but could not release BK. The cleavage pattern of MASPs is similar but not strictly identical to that of kallikrein. The catalytic efficiency of HK cleavage by a recombinant version of MASP-1 and MASP-2 was about 4.0×102 and 2.7×102 M−1s−1, respectively. C1-inhibitor, the major inhibitor of factor XIIa and kallikrein, also prevented the cleavage of HK by MASPs. In all, a new factor XII- and kallikrein-independent mechanism of bradykinin production by MASP-1 was demonstrated, which may contribute to the pro-inflammatory effect of the lectin pathway of complement and to the elevated bradykinin levels in HAE patients.

Local kallikrein–kinin system is involved in podocyte apoptosis under diabetic conditions

The kallikrein-kinin system (KKS) serves as the physiologic counterbalance to the renin-angiotensin system. This study was conducted to examine the changes in the expression of KKS components in podocytes under diabetic conditions and to elucidate the functional role of bradykinin (BK) in diabetes-associated podocyte apoptosis. Thirty-two rats were injected with either diluent (n = 16, C) or with streptozotocin intraperitoneally (n = 16, DM), and 8 rats from each group were treated with BK infusion for 6 weeks. Immortalized mouse podocytes were cultured in media containing 5.6 mmol/l glucose (NG), NG + 10(-7) mol/l AII (AII), or 30 mmol/l glucose (HG) with or without 10(-8) mol/l BK. Urinary albumin excretion was significantly higher in DM rats, and this increase was ameliorated by BK. Not only kininogen, kallikrein, and BK B1- and B2-receptor expression but also BK levels were significantly decreased in DM glomeruli and in cultured podocytes exposed to HG. The changes in the expressions of apoptosis-related molecules and the increase in the number of apoptotic cells in DM glomeruli as well as in HG- and AII-stimulated podocytes were significantly abrogated by BK. The suppressed KSS within podocytes under diabetic condition was associated with podocyte apoptosis, suggesting that BK may be beneficial in preventing podocyte loss in diabetic nephropathy.

Angiotensin II receptor blocker–induced angioedema in the oral floor and epiglottis

We report the rare case of angioedema (also known as Quincke edema), which was induced by valsartan, an angiotensin II receptor blocker (ARB). ARBs are a new class of antihypertensive agent that is developed to exclude the adverse effects of angiotensin-converting enzyme inhibitors. In theory, ARBs do not contribute to the occurrence of angioedema because they do not increase the serum level of bradykinin, the responsible substance for angioedema. However, some reports of ARB-induced angioedema have recently been published. In this study, we present the forth case and the first Asian case of angioedema due to valsartan, which is one of the ARBs. Otolaryngologist should be wary of the prescribing ARB and discontinue ARBs treatment soon, if angioedema is recognized.

Bradykinin and the Pathogenesis of Hereditary Angioedema

Bradykinin and the Pathogenesis of Hereditary Angioedema

Safety and Efficacy of Imidapril in the Treatment of Essential Hypertension

Angiotensin converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) are one of the renin angiotensin system (RAS) inhibitors widely used for the treatment of hypertension. Recently, Blood Pressure Lowering Treatment Trialists’ Collaboration (BPLTTC) meta-analysis showed that ACEIs had the blood pressure independent beneficial effects on coronary heart events. In this review, we summarized our current knowledge about ACEIs especially imidapril and re-evaluated ACEIs among other RAS inhibitors (RASIs) because ACEIs have wide ranges of beneficial effects in addition to the ACE inhibition which other RASIs do not have such as the up-regulation of bradykinin level, substance P level, the inhibition of matrix metalloproteinase (MMP) activity and stabilization of coronary plaque.

Treatment with marine collagen peptides modulates glucose and lipid metabolism in Chinese patients with type 2 diabetes mellitus

This study was aimed at examining the therapeutic effects of marine collagen peptides (MCPs) from fish hydrolysate in Chinese patients with type 2 diabetes mellitus (T2DM). A total of 100 diabetic patients and 50 healthy controls were recruited. Diabetic patients were randomized into treatment and control groups. The patients in the treatment group received an additional 13g of MCPs daily for 3months. Their blood samples were collected before, and 1.5 and 3months after, treatment to evaluate glucose and lipid metabolism. The levels of serum high-sensitivity C-reactive protein (hs-CRP), nitric oxide (NO), bradykinin, prostacyclin (PGI2), and adipokines were determined. Significantly reduced levels of fasting blood glucose, human glycated hemoglobin A1c (GHbA1c), fasting blood insulin, total triglycerides, total cholesterol, low-density lipoprotein, and free-fatty acids, but increased levels of insulin sensitivity index and HDL were observed in T2DM patients following treatment with MCPs for 1.5 and 3months. The values of these measures were significantly lower or higher than those of patient controls (p< 0.01), respectively. Interestingly, significantly decreased levels of hs-CRP and NO, but increased levels of bradykinin, PGI2, and adiponectin were detected in MCP-treated T2DM patients (p< 0.01), as compared with their basal values or the levels in patient controls. MCP treatment improved glucose and lipid metabolism in diabetic patients.

Prolylcarboxypeptidase Deficiency Is a Risk Factor for Arterial Thrombosis and Hypertension

AbstractAbstract 651 Background.Prolylcarboxypeptidase (PRCP), an S28 serine protease, degrades bradykinin, angiotensin II, and alpha melanocyte stimulating hormone and activates prekallikrein to plasma kallikrein (Blood 103:4554, 2004). In GWAS, it has been recognized as a risk factor for metabolic syndrome, hypertension, and pre-eclampsia. We postulated that PRCP murine hypomorphs (PRCPgt/gt) have a cardiovascular phenotype. Methods and Results.PRCP is mostly found in kidney in proximal tubules. In arteries, it is found both on endothelium and in media. A gene-trap murine hypomorph was created with 7% mRNA and 23% PRCP antigen in renal tissue. Using the Rose Bengal carotid artery thrombosis models, PRCPgt/gt mice had shorter carotid artery occlusion times (24±3 min [mean±SD]) compared to wild type (52±8 min). On a 4% ferric chloride carotid artery thrombosis assay PRCPgt/gt occluded in 21±8 min whereas wild type do not occlude at 60 min. Pharmacologic inhibition of PRCP with Z-pro-prolinal or plasma kallikrein with soybean trypsin inhibitor, Pro-Phe-Arg-Chloromethylketone or PKSI-572 in 3 mouse strains also shortened the time to carotid artery occlusion. PRCPgt/gt were constitutively hypertensive during the late night cycle (122±5 mm Hg mean arterial pressure vs 114±6 mm Hg for wildtype) as measured by carotid artery telemetry. Treatment of these animals with the mitochondria specific antioxidant mitoTEMPO significantly reduced (113±7 mm Hg) the elevated BP. Plasma angiotensin II and bradykinin levels were unaltered in PRCPgt/gt. PRCPgt/gt plasma had a significant increase in contact activation-induced thrombin generation. Aortic and renal reactive oxygen species (ROS) were increased (3.2-fold and 2.8-fold, respectively) in PRCPgt/gt mice as determined by dihydroethidium (DHE) fluorescence. PRCPgt/gt aortic and renal superoxide measured by lucigenin luminescence also was increased (1.6-fold and 1.7-fold, respectively). In PRCPgt/gt kidneys Amplex Red fluorescence, a measure of hydrogen peroxide, was increased 2.4-fold. Renal tissue had 1.6-fold increased uncoupled eNOS on SDS-PAGE. Arterial occlusion times in PRCPgt/gt were corrected by treatment with antioxidant apocynin or tempol. PRCP siRNA knockdowns in HUVEC or mesenchymal embryonic fibroblasts prepared from PRCPgt/gt embryos had increased constitutive DHE fluorescent ROS (2.1-fold and 1.4-fold, respectively). PRCPgt/gt aorta had decreased expression of Kruppel-like factors 2 and 4, thrombomodulin and eNOS. Moreover, PRCP knockdowns in HUVEC had 36% reduced eNOS mRNA expression. Conclusion.These investigations indicate that PRCP is a specific gene/protein target for arterial thrombosis risk and hypertension. Its presence modulates constitutive cell and tissue ROS. Arterial thrombosis risk is related to effect of ROS on endothelial cell anticoagulant mechanisms. Disclosures:No relevant conflicts of interest to declare.

Therapeutic Effects of Marine Collagen Peptides on Chinese Patients With Type 2 Diabetes Mellitus and Primary Hypertension

IntroductionMarine collagen peptides (MCPs) from deep sea fish are shown to ameliorate hyperlipidemia in animal models. The study aimed at examining the effects of MCPs on glucose and lipid metabolism in Chinese patients with type 2 diabetes mellitus (T2DM) and primary hypertension. MethodsOne hundred patients with T2DM and primary hypertension and 50 healthy subjects (normal controls) were recruited for a randomized double blind study. The patients were randomized into MCPs treatment or patient control groups (n=50 per group). Both patient controls and normal controls were given carboxymethylcellulose twice daily whereas the MCPs treatment group was given MCPs twice daily for 3months. Blood pressure, glucose and lipid metabolism, serum high-sensitivity C-reactive protein, cytochrome P450, nitric oxide, bradykinin, prostacyclin, creatinine, uric acid and adipokines were measured at baseline, 1.5 and 3months after treatment. All patients received regular medicines for control of hyperglycemia and hypertension. ResultsCompared with patient controls, significantly reduced levels of fasting blood glucose, HbA1c, diastolic blood pressure, mean arterial pressure and creatinine but increased levels of Insulin Sensitivity Index and Insulin Secretion Index were observed in patients receiving MCPs treatment. Furthermore, significantly reduced levels of serum triglycerides, total cholesterol, low-density lipoprotein, free fatty acids, cytochrome P450, nitric oxide and prostacyclin but increased levels of high-density lipoprotein, bradykinin and adiponectin were detected in patients taking MCPs. ConclusionsMCPs supplement may benefit glucose and lipid metabolism, insulin sensitivity, renal function and hypertension management in Chinese patients with T2DM and hypertension.