Angiotensin-converting Enzyme Activity Levels Research Articles

Piper sarmentosum Roxb. Inhibits Angiotensin-Converting Enzyme Activity in Phorbol 12-Myristate-13-Acetate-Induced Endothelial Cells.

Angiotensin-converting enzyme (ACE) plays a crucial role in the pathogenesis of hypertension. Piper sarmentosum Roxb., an herb known for its antihypertensive effect, lacks a comprehensive understanding of the mechanism underlying its antihypertensive action. This study aimed to elucidate the antihypertensive mechanism of aqueous extract of P. sarmentosum leaves (AEPS) via its modulation of the ACE pathway in phorbol 12-myristate-13-acetate (PMA)-induced human umbilical vein endothelial cells (HUVECs). HUVECs were divided into five groups: control, treatment with 200 µg/mL AEPS, induction 200 nM PMA, concomitant treatment with 200 nM PMA and 200 µg/mL AEPS, and treatment with 200 nM PMA and 0.06 μM captopril. Subsequently, ACE mRNA expression, protein level and activity, angiotensin II (Ang II) levels, and angiotensin II type 1 receptor (AT1R) and angiotensin II type 2 receptor (AT2R) mRNA expression in HUVECs were determined. AEPS successfully inhibited ACE mRNA expression, protein and activity, and angiotensin II levels in PMA-induced HUVECs. Additionally, AT1R expression was downregulated, whereas AT2R expression was upregulated. In conclusion, AEPS reduces the levels of ACE mRNA, protein and activity, Ang II, and AT1R expression in PMA-induced HUVECs. Thus, AEPS has the potential to be developed as an ACE inhibitor in the future.

Sarcoidosis clinical picture governs alterations in type 17 T helper cell subset composition and cytokine profile

Immune cell hyperactivation along with cytokines they overproduce plays an important role in sarcoidosis and related disease pathogenesis. A central place in the immunopathogenesis of sarcoidosis is held by diverse cell-mediated reactions governed by T helper (Th) cell populations including Th17 subsets and relevant signature cytokines. We studied peripheral blood plasma samples of the patients with sarcoidosis (n = 123): 18% with acute and 82% with chronic course. The control group — samples from healthy volunteers (n = 43). T cell subset composition was assessed by flow cytometry. Cytokine concentrations (pg/mL) were measured by multiplex analysis using xMAP technology (Luminex). The level of “classical” Th17 turned out to be significantly reduced in acute vs chronic sarcoidosis: 28.3% vs 33.3% (p = 0.046). The level of “double-positive” Th17 (DP Th17) was significantly increased in chronic and acute vs control group: 31.7% and 34.2% vs 26.2% (p < 0.001 in both cases), without differences patient inter-group; “non-classical” Th17.1 were shown to have significantly reduced level only in chronic vs healthy subjects: 27.9% and 35.9% (p < 0.001). Clinical and laboratory diagnostic characteristics for blood DP Th17 levels in CD45RA-negative Th effector memory cells in sarcoidosis: in acute sarcoidosis vs healthy subjects, they were characterized by sensitivity — 82%; specificity — 71%, whereas in chronic: 67% and 56%, respectively. In patients with sarcoidosis vs healthy subjects were found to have significantly increased level of IL-12 (p70) — 1.3 vs 0.56, p = 0.028; IL-17A — 1.5 vs 0.43, p < 0.001; IFNγ — 4.1 vs 1.1, p < 0.001; TNFα — 21.7 vs 6.7, p < 0.001. Thus, CCR6+ Th17 and DP Th17 subsets and relevant signature cytokines are important in diagnostics of sarcoidosis of varying clinical course: a direct correlation was shown between the level of angiotensin-converting enzyme activity and percentage of memory DP Th17; disease progression vs regression had significantly reduced absolute number of total CD45RA- memory and CM Th17; extrapulmonary manifestations had a significantly increased percentage of DP Th17 CD45RA- and EM DP Th17; in chronic sarcoidosis are significantly increased concentration of IL-17A, IFNγ, IL-12 and positively correlation between IFNγ and the activity of angiotensin-converting enzyme.

The ACE rs1799752 Variant Is Associated with COVID-19 Severity but Is Independent of Serum ACE Activity in Hospitalized and Recovered Patients.

This paper assesses the association of the insertion/deletion ACE (angiotensin-converting enzyme) variant (rs1799752 I/D) and the serum ACE activity with the severity of COVID-19 as well as its impact on post-COVID-19, and we compare these associations with those for patients with non-COVID-19 respiratory disorders. We studied 1252 patients with COVID-19, 104 subjects recovered from COVID-19, and 74 patients hospitalized with a respiratory disease different from COVID-19. The rs1799752 ACE variant was assessed using TaqMan® Assays. The serum ACE activity was determined using a colorimetric assay. The DD genotype was related to risk for invasive mechanical ventilation (IMV) requirement as an indicator of COVID-19 severity when compared to the frequencies of II + ID genotypes (p = 0.025, OR = 1.428, 95% CI = 1.046-1.949). In addition, this genotype was significantly higher in COVID-19 and post-COVID-19 groups than in the non-COVID-19 subjects. The serum ACE activity levels were lower in the COVID-19 group (22.30 U/L (13.84-32.23 U/L)), which was followed by the non-COVID-19 (27.94 U/L (20.32-53.36 U/L)) and post-COVID-19 subjects (50.00 U/L (42.16-62.25 U/L)). The DD genotype of the rs1799752 ACE variant was associated with the IMV requirement in patients with COVID-19, and low serum ACE activity levels could be related to patients with severe disease.

Improvement in Blood Pressure After Intermittent Fasting in Hipertension: Could Renin-Angiotensin System and Autonomic Nervous System Have a Role?

Although it has been reported that the intermittent fasting (IF) diet has positive effects on heart health and improvement in blood pressure, it has not been sufficiently clarified how it could have these positive effects yet. We aimed to evaluate the effects of IF on the autonomic nervous system (ANS) and renin-angiotensin system (RAS), which are closely related to blood pressure. Seventy-two hypertensive patients were included in the study, and the data of 58 patients were used. All the participants fasted for about 15-16 hours for 30 days. Participants were evaluated with 24-hour ambulatory blood pressure monitoring and Holter electrocardiography before and after IF; also, 5 ml venous blood samples were taken for assessment of Serum angiotensin I (Ang-I) and angiotensin II (Ang-II) levels and angiotensin-converting enzyme (ACE) activity. For data analysis, the p-value <0.05 was accepted as significant. Compared to pre-IF, a significant decrease was observed in the patients' blood pressures in post-IF. An increase in high-frequency (HF) power and the mean root square of the sum of squares of differences between adjacent NN intervals (RMSSD) were observed after the IF protocol (p=0.039, p=0.043). Ang-II and ACE activity were lower in patients after IF (p=0.034, p=0.004), and decreasing Ang-II levels were determined as predictive factors for improvement of the blood pressure, like the increase in HF power and RMSSD. The present findings of our study demonstrated an improvement in blood pressure and the relationship of blood pressure with positive outcomes, including HRV, ACE activity, and Ang-II levels after the IF protocol.

The importance of verifying manufacturer’s claim on specimen stability: An example in serum angiotensin converting enzyme testing

Appropriate specimen handling is integral to quality and minimizing medical errors. Clinical laboratories often rely on manufacturer’s claims for handling specimens, such as sample stability conditions. Serum angiotensin converting enzyme (ACE) is an example in which manufacturer claims and stability in the literature is limited. The purpose of this study was to demonstrate the importance to verify manufacturer’s stability using serum ACE as an example. Serum was collected from 39 healthy volunteers and ACE activity levels measured at baseline, after 4 h, 1, 3, 7 days at room temperature, after 3, 7, and 14 days refrigerated at 4 °C, after 1, 2, 4 and 8 weeks frozen at −20 °C, and after three freeze/thaw cycles. An additional 42 discarded patient serum specimens were re-analyzed after 1 or 2 weeks frozen at −20 °C. To evaluate stability performance, percent difference was compared to the clinical acceptance criteria, which was defined as a ½ total allowable error of ±10.9 %. This study found serum ACE to be stable 4 h at room temperature, 14 days refrigerated at 4 °C, up to 1 week frozen at −20 °C, and up to three freeze/thaw cycles. The preferred storage condition for serum ACE is refrigerated at 4 °C as there was minimal change in percent bias over the 14 day period. The false increase observed in samples stored frozen longer than 1 week could impact clinical decision making. The stability findings differed from manufacturer claims, highlighting the importance of verifying stability, especially for esoteric testing such as serum ACE where specimens travel long distances in varying climates to reach centralized testing locations.

Роль ангиотензинпревращающего фермента и рецепторов ангиотензина ii второго типа в патогенезе пролиферативных заболеваний предстательной железы

Angiotensin converting enzyme, angiotensin II, angiotensin II receptors of the first and second types represent the "classical" axis of regulation of the renin-angiotensin system. OBJECTIVE: to analyze the role of the components of the renin-angiotensin system in the pathogenesis of proliferative lesions of the prostate glan MATERIALS AND METHODS: The study included 63 patients who underwent transrectal prostate biopsy. The first group consisted of 19 patients with benign prostatic hyperplasia, the second group consisted of 19 men whose prostate cancer was detected during repeated biopsy, the third group consisted of 25 men with prostate cancer detected during primary prostate biopsy. The expression of angiotensin II type II (AT2-R) receptors in prostate tissue was evaluated using primary polyclonal antibodies Angiotensin II Type 2 Receptor and the EnVision FLEX imaging system (Dako, Denmark) according to a standard technique. The activity of angiotensin converting enzyme (ACE) was determined in the secret of the prostate gland, RESULTS: It was found that the activity of ACE in the secret of the prostate gland in proliferative diseases is significantly higher than in the "healthy" prostate. The highest activity of ACE was noted for benign prostatic hyperplasia, and the minimum - for prostate cancer. The expression of AT2-R in prostate tissues in proliferative diseases of the prostate gland has its own characteristics. The expression of AT2-R in the prostate stroma turned out to be the same, in the nuclei of epithelial cells, the level of expression of AT2-R decreased in the range of BPH-PIN-CP. Thus, an increase in the activity of ACE, the accumulation of angiotensin II in prostate secretions in proliferative prostate diseases against the background of a deficiency of AT2-R is the metabolic basis of malignant transformation of the prostate gland. CONCLUSION: The levels of ACE activity in prostate secretion and the expression of AT2-R in prostate tissue during primary prostate biopsy can be considered as promising prognostic tools for early detection of prostate malignancy.

Angiotensin-Converting Enzyme Activity May Predict Disease Severity in Psoriasis

Psoriasis is a multifactorial disease, with many genetic risk factors, one of which seems to be the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism. ACE activity has been shown to be higher in psoriatic patients and it suggests an oxidative stress state, as seen in many cardiovascular disorders. We aimed to explore the association between ACE activity and polymorphisms and cardiovascular risk amongst psoriatic patients. We included 64 psoriatic patients and 1091 controls and compared ACE I/D polymorphism genotype and serum activity for both groups. ACE genotypes were similar in psoriatic patients and controls. Notably, serum ACE activity was higher in psoriatic patients (19.09 ± 2.86 U/mL) compared to controls (11.85 ± 0.40 U/mL), p = 0.015. Non-HDL cholesterol was significantly lower in II polymorphism (p = 0.037). Psoriatic activity (PASI) was associated with a higher cardiovascular risk estimated by lower HDL concentrations (r = −0.496, p = 0.007), and higher triglyceride levels (r = 0.421, p = 0.020) and TC/HDL and LDL/HDL ratios (r = 0.612, p &lt; 0.001 and r = 0.437, p = 0.023, respectively). Patients with psoriasis have higher ACE activity levels, independent of ACE genotype. Moreover, disease activity correlated with cardiovascular risk. This could support the eventual role of ACE as a possible biomarker for disease severity and cardiovascular risk in psoriasis patients.

Green Tea Suppresses the Radiation-Induced Increase of the AngiotensinConverting Enzyme &amp; Reactive Oxygen Species in the Aorta of Rats

The consumption of green tea reduces the risk of cardiovascular diseases and suppresses the development of atherosclerosis. The main factor for the initiation and progression of atherosclerosis is an increase in the production of reactive oxygen species (ROS) in vessels. A significant contribution to the increase in ROS production is made by increased concentration of angiotensin II, a product of the angiotensin-converting enzyme (ACE). The effect of green tea on the level of ROS and ACE activity in blood vessels in vivo has not yet been studied. The activity of ACE in aorta sections of rat was determined by measuring the hydrolysis of hippuryl-L-histidyl-L-leucine, and the production of ROS was estimated from the oxidation of dichlorodihydrofluorescein. Green tea inhibited the radiation-induced activation of the ACE in the aorta of rats on intraperitoneal (i.p.) and peroral administration. Six hours after the administration of tea, the activity of ACE in irradiated rats decreased to the control level, and by 24 h after administration, the tea did not almost affect the ACE activity. On i.p. administration, effective doses were lower than on peroral administration. The concentration of orally administered tea that inhibited the ACE activation in irradiated rats by 50% (IC50) was 1 ml of an extract of 2.1 g of tea brewed per 100 ml of water. One milliliter of i.p. administered green tea (1 g per 100 ml of water) completely suppressed the increased ROS production in the aorta of irradiated rats.

Activation of Ang-(1-7)/Mas Receptor Is a Possible Strategy to Treat Coronavirus (SARS-CoV-2) Infection.

The renin-angiotensin system is involved in the pathophysiology of inflammatory diseases through an increase in angiotensin converting enzyme (ACE)/angiotensin (Ang) II/AT1 receptor axis activity. It has been shown that ACE activity is increased in acute respiratory distress syndrome and there is a strong correlation between the level of ACE activity and the degree of lung injury. SARS-CoV-2, the new coronavirus that causes COVID-19, similar to other coronaviruses, was recently shown to use ACE2 as a receptor to get into host cells. However, it has been reported that most of the treatments that stimulates the ACE2/Ang-(1-7)/Mas axis induces beneficial effects, such as, antihypertensive, anti-inflammatory, anti-proliferative, anti-thrombotic and anti-fibrotic. Here we discussed the potential of activation of Ang-(1-7)/Mas pathway as strategy to treat COVID-19.

Genetic Association of ACE Polymorphism with Sarcopenia and Effects of Genetic Regulation of ACE Activity on Muscle Function

The purpose of this study was to investigate associations between skeletal muscle mass and ACE polymorphism, or sarcopenia‐related candidate gene, and to examine the effects of genetical angiotensin‐converting enzyme (ACE) activity on physical performance and respiratory muscle function in Korean adults. For this study, 1,464 Korean adults aged 18~79 were recruited. The anthropometrics were 1.69±0.06m (height), 63.1±5.5kg (weight), 29.4±6.5% (percent body fat), and 24.5±3.0kg/m2 (body mass index). Fat‐free mass, physical performance, gait speed (Timed Up‐and‐Go), pulmonary function (maximal inspiration and expiration pressure) and fatiguing maximum voluntary isometric contraction (40% MVIC) of ankle plantar flexor muscles with dynamic Electromyography were tested. Data of body composition and muscle functions were analyzed using one‐way ANOVA and post‐hoc Scheffe test for continuos variables and the Chi‐square test and host‐hoc Bonfferioni correction for countable variables. Blood samples for the whole blood and serum were obtained and assayed for circulating ACE activity and the ACE I/D genotype. The distribution of ACE polymorphism throughout the groups was analyzed using the Chi‐square test and host‐hoc Bonferroni correction for genetic distribution and multiple logistic regression analysis for the odds ratios (ORs) with 95% confidence intervals (CIs). We found that the distribution of ACE Indel genotype for sarcopenia was significantly different from normal population who have normal or high fat‐free mass index. Especially, we found a significantly higher (p&lt;.05) distribution of DD genotype in sarcopenia participants (27%) than the incidence (12.5%) in normal population. The D allele of ACE genotypes in older adults indicated significantly slower gait speed than I allele of them in the Timed Up‐and‐go test (p&lt;.05), and significantly lower levels for maximal inspiration and expiration pressure (p&lt;.05). The II genotype in older adults indicate the highest tolerance of muscle fatigue during muscle contraction (p&lt;.05). In conclusion, ACE Indel polymorphism and level of ACE activity is associated with sarcopenia in older adults and would genetically regulate muscle function in part. Our findings suggest that genetical concentrations of angiotensin‐converting enzyme should play a role in determining low muscle mass, slow walking speed, respiratory muscle function, and fatigue after muscle contraction in individuals. Therefore, examining ACE Indel polymorphism and ACE activity level could be used to predict sarcopenia and muscle function, and subsequently this information can be applicable to prevention and treatment to the aging muscle.Support or Funding InformationThis research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (358‐2011‐1‐G00025).

Antioxidant, Hypolipidemic and Angiotensin Converting Enzyme Inhibitory Effects of Flavonoid-rich Fraction of Hyphaene thebaica (Doum Palm) Fruits on Fat-fed Obese Wistar Rats

Aims: This study investigated the antioxidant, hypolipidemic and angiotensin converting enzyme (ACE) inhibitory effects of flavonoid-rich fraction of H. thebaica on fat-fed obese wistar rats.&#x0D; Study Design: Twenty-five rats were divided into 5 groups of 5 rats each: Control (standard diet, untreated), Obese control (Fat-fed, untreated), Standard control (Fat-fed, treated with 70 mg/kg Atorvastatin), Groups 4 and 5 (Fat-fed, treated with 100 and 250 mg kg-1 flavonoid-rich fraction, respectively). The rats were given high fat diet to induce obesity, after which treatment was administered for fourteen (14) days, and on the 15th day, rats were sacrificed and blood samples collected.&#x0D; Results: From the results, induction of obesity significantly (P&lt;0.05) increased body weight, some lipoproteins, ACE activity, superoxide dismutase, catalase and glutathione peroxidase levels, while HDL cholesterol and malondialdehyde levels decreased. Treatment of obese rats with the standard drug, atorvastatin and flavonoid-rich fraction of H. thebaica significantly (P&lt;0.05) decreased ACE activity, total cholesterol, triglyceride and LDL cholesterol, while HDL cholesterol and malondialdehyde increased.&#x0D; Conclusion: This study has demonstrated that the flavonoid-rich fraction of H. thebaica is hypolipidemic, possesses antioxidant activities, and may contain potent ACE inhibitors.

Study of angiotensin-converting enzyme insertion/deletion polymorphism, enzyme activity and oxidized low density lipoprotein in Western Iranians with atherosclerosis: a case-control study

BackgroundIt has been indicated that Angiotensin-Converting Enzyme Insertion/Deletion (ACE I/D) polymorphism (rs4646994) could be regarded as a genetic factor that raises the risk of CAD through its impact on the activity of Angiotensin-Converting Enzyme (ACE) and angiotensin II level. The present study seeks to examine the relationship between ACE I/D polymorphism with the risk of atherosclerosis. Moreover, its potential effects on ACE activity and oxLDL level are investigated.MethodsIn this study, 145 healthy individuals and 154 patients (143 males and 156 females) were selected among the subjects referred to Shahid Madani Hospital. Atherosclerosis was determined in all subjects with gold standard angiography. Blood samples were collected, used to isolate white blood cells (WBC) and serum separation. The DNA was extracted and the polymorphism was determined by polymerase chain reaction (PCR). The enzyme activity was measured using high-performance liquid chromatography (HPLC).ResultsThis study indicated that patients with atherosclerosis had higher levels of oxidized Low-Density Lipoprotein (oxLDL) and ACE activity (P < 0.05) as compared to controls. Although we found a significant association between ACE I/D polymorphism genotype and the allele with atherosclerosis in the male group, there were no association when the entire patient group was compared to the entire control group.ConclusionOur study revealed the ACE I/D polymorphism of the ACE gene may not be an independent risk factor in the development of atherosclerosis and evaluation of ACE activity level is more important in evaluating the risk of disease. The researchers found no relation between ACE I/D polymorphism and atherosclerosis and also between types of genotype, ACE activity, and OxLDL level.

Angiotensin-converting enzyme activity in Cavalier King Charles Spaniels with an ACE gene polymorphism and myxomatous mitral valve disease.

Myxomatous mitral valve disease (MMVD) is the most common heart disease in the dog. It is particularly common in the Cavalier King Charles Spaniel (CKCS) breed and affected dogs are frequently managed with angiotensin-converting enzyme inhibitors (ACE-I). We have previously identified a canine ACE gene polymorphism associated with a decrease in angiotensin-converting enzyme (ACE) activity. The aim of this study was to evaluate for the prevalence of the ACE polymorphism in CKCS with mitral valve disease and to determine whether the presence of the polymorphism is associated with alterations in ACE activity at different stages of cardiac disease. Seventy-three dogs with a diagnosis of mitral valve disease were evaluated and a blood sample was drawn for ACE polymorphism genotyping and ACE activity measurement. Forty-three dogs were homozygous for the ACE polymorphism; five were heterozygous and 25 were homozygous wild type. The mean age and the median severity of disease were not different for dogs with the polymorphism and dogs with the wild-type sequence. The median baseline ACE activity was significantly lower for the ACE polymorphism (27.0 U/l) than the wild-type sequence dogs (31.0 U/l) (P=0.02). Dogs with more severe disease and the ACE polymorphism had significantly lower levels of ACE activity than dogs with the wild-type sequence (P=0.03). The CKCS appears to have a high prevalence of the ACE variant. Dogs with the ACE variant had lower levels of ACE activity even in more advanced mitral valve disease than dogs without the variant. The clinical significance of this finding and its impact on the need for ACE-I in dogs with the polymorphism and heart disease deserves further study.

A novel rodent model of pregnancy complications associated with genetically determined angiotensin-converting enzyme (ACE) activity.

Brown Norway (BN) and Lewis (LW) inbred rat strains harbor different angiotensin-converting enzyme ( Ace) polymorphisms that result in higher ACE activity in BN than LW rats. Thus we hypothesized that pregnant BN rats would show pregnancy complications linked to angiotensin II (AII) activity. We performed longitudinal and cross-sectional studies in pregnant LW and BN rats. We found that BN rats have significantly higher ACE activity and AII levels at prepregnancy and throughout pregnancy compared with LW rats, except at midgestation. BN placentas and maternal kidneys had significantly higher expression of AII receptor 1 (AGTR1) and lower expression of AGTR2 than the respective LW placentas and maternal kidneys. Renin-angiotensin system activation in BN rats correlated with hypertension and proteinuria at gestational days 17-21, which were resolved after delivery. In addition, BN rat pregnancies were characterized by significant fetal loss, restricted growth in surviving fetuses, decreased uteroplacental blood flows, and decreased trophoblast remodeling of uterine arteries compared with LW pregnancies. Short-term losartan treatment significantly increased uteroplacental blood flow and fetal weight and decreased maternal blood pressure (BP) and proteinuria in BN pregnancies. In contrast, losartan treatment significantly decreased uteroplacental blood flow and fetal weight but had no significant effect on maternal BP in LW pregnancies. We conclude that Ace polymorphisms play an important role in the reproductive phenotype of BN and LW rats and that BN rats are a novel model of pregnancy complications in association with genetically controlled, increased ACE activity.

Beraprost Sodium, a Stable Analogue of PGI2, Inhibits the Renin-Angiotensin System in the Renal Tissues of Rats with Chronic Renal Failure

Chronic renal failure (CRF) is a prolonged kidney condition characterized by decreased kidney function that can eventually develop into total kidney failure. The renin-angiotensin system (RAS) helps to regulate the balance between human bodily fluids and electrolytes. The aim of the present study was to investigate the effects of a prostacyclin analogue (beraprost sodium [BPS]) on the expression of key factors associated with local RAS activities in the renal tissues of rats with CRF. After a CRF rat model was successfully established, the levels of BUN, SCr, phosphorus, and calcium were detected by an automatic biochemistry analyzer. Furthermore, the activities of malondialdehyde (MDA) and superoxide dismutase (SOD) in rat renal tissues were measured using a colorimetric method, while the activity of angiotensin-converting enzyme (ACE) was determined by ultraviolet (UV) spectrophotometry. In situ hybridization was employed to determine the expression of angiotensin II type 1 receptor (AT). Finally, the positive expression rates of cells expressing important apoptotic proteins (Bax and Bcl-2) were determined, and the protein and mRNA levels of phosphatidylinositol 3-kinase (AKT) and key factors involved in the RAS (AT1, AT2, angiotensin ACE and angiotensinogen [AGT]) were evaluated by RT-qPCR and western blot analysis. Initial observations revealed that treatment with BPS decreased the levels of BUN, SCr and phosphorus but increased calcium levels in the renal tissues of CRF rats. Additionally, BPS reduced the levels of MDA while increasing the levels of SOD, ACE activity, and AT1 expression in the renal tissues of CRF rats. BPS inhibited glomerular hypertension and hyperfiltration; increased the mRNA and protein levels of AKT and AT2; and decreased the mRNA and protein levels of AT1, AGT, and ACE in the renal tissues of CRF rats. The results of this study demonstrate that BPS, a PGI2 analogue, inhibits the expression of key factors involved in the local RAS, resulting in a delay in the occurrence and development of CRF. The key findings of the present study ultimately highlight the potential of this PGI2 analogue as a promising therapeutic strategy for treating CRF.

Angiotensin-converting enzyme activity and inhibition in dogs with cardiac disease and an angiotensin-converting enzyme polymorphism.

Objective:The objective of this study was to evaluate angiotensin-converting enzyme (ACE) activity in dogs and with and without an ACE polymorphism in the canine ACE gene, before and after treatment with an ACE inhibitor.Methods:Thirty-one dogs (20 wild-type, 11 ACE polymorphism) with heart disease were evaluated with ACE activity measurement and systolic blood pressure before and after administration of an ACE inhibitor (enalapril).Results:Median pre-treatment ACE activity was significantly lower for ACE polymorphism dogs than for dogs with the wild-type sequence (P=0.007). After two weeks of an ACE inhibitor, ACE activity was significantly reduced for both genotypes (wild-type, P<0.0001; ACE polymorphism P=0.03); mean post-therapy ACE activity was no different between the groups.Conclusion:An ACE polymorphism is associated with lower levels of ACE activity. Dogs with the polymorphism still experience suppression of ACE activity in response to an ACE inhibitor. It is possible that the genetic status and ACE activity of dogs may impact the response of dogs with this variant to an ACE inhibitor.

Fetopathies associated with exposure to angiotensin converting enzyme inhibitor from Tropaeolum majus L.

The prevalence of the use of herbal medicines is on the rise across the world, especially amongst pregnant women. A fact that draws attention is that many species commonly used by pregnant women, including the Tropaeolum majus L. (Tropaeolaceae), also present inhibitory activity on the angiotensin-converting enzyme (ACE). Herein, we have investigated the effects of T. majus extract (HETM) on fetal development, evaluating its relationship with possible ACE inhibitory activity. Pregnant Wistar rats were treated with different HETM doses (3, 30 and 300 mg/kg/day) from gestational days 8–20. Rats were sacrificed on the day 20 of pregnancy and the following parameters were evaluated: clinical symptoms of maternal toxicity; maternal body weight; feed and water intake; maternal liver, kidney, and ovary weights, maternal ACE activity and aldosterone levels, live fetuses mean; dead fetuses percentage, fetus weight, and fetal malformation. All pregnant rats treated with high HETM doses showed significant reduction in plasma ACE activity accompanied by a decrease in serum aldosterone levels. Moreover, significant changes in fetal development were observed, including growth retardation and renal damage after 20 days of gestation. Thus, data presented demonstrate the significant effects of the use of HETM on fetal development during pregnancy.

Genetic Variants of Angiotensin-Converting Enzyme Are Linked to Autism: A Case-Control Study.

BackgroundAutism is a disease of complex nature with a significant genetic component. The importance of renin-angiotensin system (RAS) elements in cognition and behavior besides the interaction of angiotensin II (Ang II), the main product of angiotensin-converting enzyme (ACE), with neurotransmitters in CNS, especially dopamine, proposes the involvement of RAS in autism. Since the genetic architecture of autism has remained elusive, here we postulated that genetic variations in RAS are associated with autism.MethodsConsidering the relation between the three polymorphisms of ACE (I/D, rs4343 and rs4291) with the level of ACE activity, we have investigated this association with autism, in a case-control study. Genotype and allele frequencies of polymorphisms were determined in DNAs extracted from venous blood of 120 autistic patients and their age and sex-matched healthy controls, using polymerase chain reaction (PCR) and PCR–restriction fragment length polymorphism (PCR–RFLP) methods.ResultsThere were strong associations between both DD genotype of ACE I/D and the D allele, with autism (P = 0.006, OR = 2.9, 95% CI = 1.64–5.13 and P = 0.006, OR = 2.18, 95% CI = 1.37–3.48 respectively). Furthermore, a significant association between the G allele of rs4343 and autism was observed (P = 0.006, OR = 1.84, 95%CI = 1.26–2.67). Moreover, haplotype analysis revealed an association between DTG haplotype and autism (P = 0.008).ConclusionOur data suggests the involvement of RAS genetic diversity in increasing the risk of autism.

Genetically-reduced serum ACE activity might be a causal risk factor for obstructive sleep apnea syndrome: A meta-analysis.

We meta-analytically summarized the associations of angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism with ACE activity and obstructive sleep apnea syndrome (OSAS) to see whether ACE activity is causally associated with OSAS. Literature search and data abstraction were done in duplicate. Sixteen articles including 2060 OSAS patients and 1878 controls were summarized. Overall, no significance was observed for the association of I/D polymorphism with OSAS, whereas carriers of II genotype (weighted mean difference or WMD, 95% confidence interval or CI, P: −11.976, −17.168 to −6.783, <0.001) or I allele (−9.842, −14.766 to −4.918, <0.001) had a lower level of serum ACE activity compared with DD genotype carriers, respectively. In subgroup analyses, carriers of II genotype were 3.806 times more likely to develop OSAS (95% CI, P: 1.865 to 7.765, <0.001) in OSAS patients with hypertension, without heterogeneity. Mendelian randomization analysis indicated there was 37.4% (95% CI: 1.115 to 3.142) and 32.4% (1.106 to 2.845) increased risk of OSAS by a reduction of 1 U/L in ACE activity for the II genotype and I allele carriers versus DD genotype carriers, respectively. There was no observable publication bias. Collectively, genetically-reduced serum ACE activity might be a causal risk factor for OSAS.

Antioxidants, endothelial dysfunction, and DCS: in vitro and in vivo study.

Reactive oxygen species (ROS) production is a well-known effect in individuals after an undersea dive. This study aimed to delineate the links between ROS, endothelial dysfunction, and decompression sickness (DCS) through the use of antioxidants in vitro and in vivo. The effect of N-acetylcysteine (NAC) on superoxide and peroxynitrite, nitric oxide (NO) generation, and cell viability during in vitro diving simulation were analyzed. Also analyzed was the effect of vitamin C and NAC on plasma glutathione thiol and thiobarbituric acid reactive substances (TBARS), plasma angiotensin-converting enzyme (ACE) activity, and angiotensin-II and DCS morbidity during in vivo diving simulation. During an in vitro diving simulation, vascular endothelial cells showed overproduction of superoxide and peroxynitrite, obvious attenuation of NO generation, and promotion of cell death, all of which were reversed by NAC treatment. After in vivo diving simulation, plasma ACE activity and angiotensin-II level were not affected. The plasma level of glutathione thiol was downregulated after the dive, which was attenuated partially by NAC treatment. Plasma TBARS level was upregulated; however, either NAC or vitamin C treatment failed to prevent DCS morbidity. During in vitro simulation, endothelial superoxide and peroxynitrite-mediated oxidative stress were involved in the attenuation of NO availability and cell death. This study is the first attempt to link oxidative stress and DCS occurrence, and the link could not be confirmed in vivo. Even in the presence of antioxidants, ROS and bubbles generated during diving and/or decompression might lead to embolic or biochemical stress and DCS. Diving-induced oxidative stress might not be the only trigger of DCS morbidity.