Hormonal influence on endothelial cell angiotensin-converting enzyme activity

1984 ◽  
Vol 247 (3) ◽  
pp. C163-C168 ◽  
Author(s):  
A. H. Krulewitz ◽  
W. E. Baur ◽  
B. L. Fanburg
Keyword(s):  
Endothelial Cells ◽  
Angiotensin Converting Enzyme ◽  
Protein Content ◽  
Hormonal Regulation ◽  
Converting Enzyme ◽  
Cell Counts ◽  
Ace Activity ◽  
Sites Of Action ◽  
Culture Supernatants

The influence of various hormones on angiotensin-converting enzyme (ACE) production and release by bovine endothelial cells in culture was studied. Dexamethasone, thyroxine (T4), and triiodothyronine (T3) stimulated ACE activity in cells and their culture supernatants without affecting cell number or protein content. The stimulating effects of dexamethasone and thyroid hormones were additive, suggesting that these hormones may have different sites of action. In addition, their stimulating effects were blocked by cycloheximide, indicating that increased enzymatic activity occurred through new protein synthesis. The exposure of cells to insulin reduced ACE activity of cells and their culture supernatants without influencing cell counts or protein content; insulin also partially inhibited the stimulation of ACE activity by dexamethasone or T3. Our studies suggest that the production of ACE by endothelial cells is under hormonal regulation. Release of ACE activity into culture supernatants parallels changes in cellular ACE activity. The results supplement previous observations made in vitro and in vivo.

Angiotensin-converting enzyme determination in plasma during therapy with converting enzyme inhibitor: two methods compared

1991 ◽  
Vol 37 (8) ◽  
pp. 1390-1393 ◽  
Author(s):  
T P Gorski ◽  
D J Campbell
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Spectrophotometric Method ◽  
Enzyme Inhibitor ◽  
Ang Ii ◽  
Converting Enzyme ◽  
Fluorometric Method ◽  
Converting Enzyme Inhibitor ◽  
Ace Activity

Abstract For normal and above-normal concentrations of angiotensin-converting enzyme (ACE; EC 3.4.15.1) activity in plasma, results of a manual fluorometric method [with hippuryl-histidyl-leucine (HHL), 5 mmol/L, as substrate] correlated well with those of an automated spectrophotometric method [with 3-(2-furylacryloyl)-L-phenylalanyl-glycyl-glycine (FAPGG), 2 mmol/L, as substrate]. However, for patients receiving converting enzyme inhibitor (CEI) therapy, the spectrophotometric method showed much greater suppression of plasma ACE activity than did the fluorometric method. To determine which of the two methods provided a more reliable indication of ACE inhibition in vivo, we measured plasma ACE, angiotensin I (ANG I), and angiotensin II (ANG II) in patients receiving the CEI perindopril. During perindopril therapy, changes in the ratio of ANG II:ANG I, an index of ACE activity in vivo, showed a close agreement with changes in plasma ACE activity measured with FAPGG as substrate, but not with HHL as substrate. We conclude that measurement of ACE activity in vitro with FAPGG as substrate provides a reliable measure of changes in conversion of ANG I to ANG II in vivo during CEI therapy.

Serum angiotensin-converting enzyme in healthy and sarcoidotic children: comparison with the reference interval for adults

1990 ◽  
Vol 36 (2) ◽  
pp. 344-346 ◽  
Author(s):  
B Bénéteau-Burnat ◽  
B Baudin ◽  
G Morgant ◽  
F C Baumann ◽  
J Giboudeau
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Hormonal Regulation ◽  
Reference Interval ◽  
Healthy Children ◽  
Age Group ◽  
Converting Enzyme ◽  
Serum Angiotensin Converting Enzyme ◽  
Age Related ◽  
Ace Activity ◽  
Physiological Variations

Abstract Angiotensin-converting enzyme (ACE) was measured in serum of 187 healthy children between the ages six months and 18 years. Results were pooled for five-year age intervals and compared with the reference values for adults that we previously determined [Clin Chem 1986;32:884-6). Results for each age group were also studied as a function of sex. Children had higher ACE activities in serum than did adults (P less than 0.001), but these activities were age-related only from age four to 18 years. Adolescents showed sex-related differences, with higher serum ACE activities in boys than in girls (P less than 0.05). Both sex- and age-related differences may be related to a steroid hormonal regulation of ACE biosynthesis. We also verified that children with sarcoidosis (n = 20) had significantly increased serum ACE activity. Such physiological variations in serum ACE activity must be taken into account for diagnosing sarcoidosis in children, for following the course of the disease, and for evaluating the accuracy of therapy.

An experimental study of the effect of zinc on the activity of angiotensin converting enzyme in serum.

1985 ◽  
Vol 31 (4) ◽  
pp. 581-584 ◽  
Author(s):  
P G Reeves ◽  
B L O'Dell
Keyword(s):  
Experimental Study ◽  
Angiotensin Converting Enzyme ◽  
Zinc Concentration ◽  
Converting Enzyme ◽  
Dietary Zinc ◽  
Assay Mixture ◽  
The Mean ◽  
Ace Activity

Abstract The activity in serum of zinc-dependent angiotensin converting enzyme (ACE), is measured to aid in diagnosis and monitor treatment of certain diseases. This report shows the effect of dietary zinc deprivation on ACE activity in the serum of rats. The mean (and SE) of the zinc concentration (mumol/L) in serum was 3.5 (0.3) in rats deprived of dietary zinc for four days, 16.3 (0.2) in control rats, and 19.8 (0.9) in rats deprived of zinc for four days, then repleted with zinc for 12 h. The respective mean (and SE) of ACE activities (nmol/mL per min) in serum were 390 (15), 543 (13), and 545 (20). Serum ACE activity was restored also by adding zinc to the assay mixture in vitro. The Vmax for ACE was 1.4 times greater when serum was diluted 40-fold as compared with twofold dilution. There was a small effect on the Km for the substrate, but the Km for zinc was decreased by 22-fold when serum was diluted 40-fold. The Vmax under these conditions was decreased by only 9%.

scholarly journals AN IN VITRO STUDY OF CINNAMOMUM ZEYLANICUM AS NATURAL INHIBITOR OF ANGIOTENSIN-CONVERTING ENZYME (ACE) ON SHEEP (OVIS ARIES) TISSUES

2016 ◽  
Vol 9 (5) ◽  
pp. 249
Author(s):  
Ranjini Hs ◽  
Padmanabha Udupa Eg ◽  
Shobha U Kamath ◽  
Manjunath Setty ◽  
Basavaraj Hadapad ◽  
...  
Keyword(s):  
Cardiovascular Diseases ◽  
Angiotensin Converting Enzyme ◽  
Methanolic Extract ◽  
Enzyme Inhibitor ◽  
Ovis Aries ◽  
Converting Enzyme ◽  
Kinetic Assay ◽  
Natural Inhibitor ◽  
Ace Activity

ABSTRACTObjective: The present study was aimed to find the angiotensin-converting enzyme (ACE) inhibitory activity using the methanolic extract ofCinnamomum zeylanicum (as a natural inhibitor) on sheep tissues as the enzyme source.Methods: Hippuryl-histidyl-leucine (HHL) as a substrate, tissue ACE activity was measured spectrophotometrically at 228 nm. For an incubationperiod of 30 minutes at 37°C, the linearity of ACE activity of kidney, lung, and testis enzyme was established. A known medicinal plant C. zeylanicumwas used as natural inhibitor of ACE. In this enzyme assay, inhibitory effect of methanolic extract of C. zeylanicum on kidney, lung and testicular ACEwas determined. ACE activity was confirmed by captopril, a standard inhibitor of ACE.Results: In the presence of a methanolic extract of C. zeylanicum (10:1), ACE activity was determined and this has inhibited ACE activity verysignificantly. C. zeylanicum leaves extract has reduced sheep kidney, lung, and testis ACE activity by 70.06%, 12.63%, and 20.23%, respectively.Conclusion: Significant inhibition was observed in the kidney ACE than in lung and testis ACE activity. This can propose that there may be a possiblerole in controlling blood pressure or reduction in cardiovascular diseases. Some plants with the great medicinal property may be considered aspromising sources of natural inhibitors of ACE for medicine and commercial uses. This comprehensive study may show numerous beneficial effects asa potential therapeutic agent for lowering blood pressure.Keywords: Angiotensin-converting enzyme, Natural angiotensin-converting enzyme inhibitor, Kinetic assay, Hippuryl-histidyl-leucine, Cinnamomumzeylanicum, Cardiovascular diseases.

Endothelial cells internalize monoclonal antibody to angiotensin-converting enzyme

1996 ◽  
Vol 270 (5) ◽  
pp. L704-L713 ◽  
Author(s):  
V. R. Muzykantov ◽  
E. N. Atochina ◽  
A. Kuo ◽  
E. S. Barnathan ◽  
K. Notarfrancesco ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Endothelial Cells ◽  
Angiotensin Converting Enzyme ◽  
Umbilical Vein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Affinity Constant ◽  
Converting Enzyme

We investigated the fate of MAb 9B9, a monoclonal antibody to angiotensin-converting enzyme (ACE), which binds to endothelium both in vitro and in vivo. Using cultured human umbilical vein endothelial cells (HUVEC) and isolated perfused rat lungs (IPL), we demonstrated specific and saturable binding of 125I-labeled MAb 9B9 at 4 degrees C [affinity constant (Kd) = 20-50 nM, maximal number of binding sites (Bmax) = 1.5-3.0 x 10(5) sites/cell]. When 125I-MAb 9B9 was bound to HUVEC at 37 degrees C, only 40% of cell-associated radioactivity was acid elutable, suggesting antibody internalization. This was confirmed by finding that 1) the amount of MAb 9B9 uptake at 37 degrees C was higher than at 4 degrees C both in HUVEC and IPL; 2) binding of 125I-labeled streptavidin with HUVEC and IPL pretreated with biotinylated MAb 9B9 (b-MAb 9B9) was diminished in a temperature- and time-dependent fashion at 37 degrees C; and 3) b-MAb 9B9 bound to HUVEC at 37 degrees C was found intracellularly by ultrastructural analysis using streptavidin gold. Intracellular 125I-MAb 9B9 was found in microsomal fractions of lung homogenate from IPL and after intravenous (iv) injections in rats. Degradation of internalized MAb 9B9 was minimal, since > 90% of cell-associated 125I label remained precipitable by trichloracetic acid in HUVEC, IPL, and in vivo. Autoradiography of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of lung homogenates made as late as several days after iv injections of 125I-MAb 9B9 in rats demonstrated a predominant band above 140 kDa. These data indicate that endothelial cells either in vitro or in vivo internalize the ACE ligand MAb 9B9 without significant intracellular degradation. Therefore MAb 9B9 may be useful for selective intracellular delivery of drugs to the pulmonary vascular endothelium after systemic administration.

Effect of Ginsenoside Rgl on the Release of Enzymes by Cultured Endothelial Cells

1992 ◽  
Vol 20 (01) ◽  
pp. 91-101 ◽  
Author(s):  
Yumiko Ushio
Keyword(s):  
Endothelial Cells ◽  
Angiotensin Converting Enzyme ◽  
Plasminogen Activator ◽  
Umbilical Vein ◽  
Surface Membrane ◽  
Morphological Alteration ◽  
Converting Enzyme ◽  
Promoting Effect ◽  
Umbilical Vein Endothelial Cells

The effects of ginsenoside Rgl, isolated from Ginseng Radix, on the secretion of plasminogen activator and angiotensin-converting enzyme from cultured human umbilical vein endothelial cells were investigated in vitro. Ginsenoside Rgl significantly increased the secretion of plasminogen activator from the cells both with and without stimulation of the cells by thrombin. Ginsenoside Rgl also remarkably induced the secretion of angiotensin-converting enzyme from the cells. Furthermore, ginsensoside Rgl showed some morphological alteration in the surface membrane of the cells. In addition, survival-promoting effect of CPAE cell line by ginsenoside Rgl was observed.

Distribution and Properties of Angiotensin-Converting Enzyme in Cerebral Microvessels of the Rabbit and Rat

1981 ◽  
Vol 61 (s7) ◽  
pp. 249s-251s ◽  
Author(s):  
P. Brecher ◽  
Vandana Hingorani ◽  
Karen Reininga ◽  
A. V. Chobanian
Keyword(s):  
Endothelial Cells ◽  
Angiotensin Converting Enzyme ◽  
Rat Brain ◽  
Lipoprotein Lipase ◽  
Rabbit Brain ◽  
Aortic Tissue ◽  
Converting Enzyme ◽  
Cerebral Microvessels ◽  
Cerebral Microvasculature ◽  
Ace Activity

1. Angiotensin-converting enzyme (ACE) activity was threefold greater in isolated cerebral microvessels obtained from rabbit brain than rat brain. 2. ACE activity was distributed throughout the cerebral microvasculature, since differences were not found between preparations enriched in capillaries as compared with those enriched in arterioles and venules. 3. Aortic tissue from rat and rabbit had little ACE activity compared with the microvessels. 4. ACE activity was tightly associated with endothelial cells and was not released by heparin under conditions where lipoprotein lipase was effectively removed.

scholarly journals Angiotensin-converting enzyme inhibitors attenuate propofol-induced pro-oxidative and antifibrinolytic effect in human endothelial cells

2017 ◽  
Vol 18 (1) ◽  
pp. 147032031668719 ◽  
Author(s):  
Marzena Wojewodzka-Zelezniakowicz ◽  
Anna Gromotowicz-Poplawska ◽  
Wioleta Kisiel ◽  
Emilia Konarzewska ◽  
Janusz Szemraj ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Angiotensin Converting Enzyme ◽  
Enzyme Inhibitors ◽  
Umbilical Vein ◽  
Angiotensin Converting Enzyme Inhibitors ◽  
Mrna Levels ◽  
Converting Enzyme ◽  
Converting Enzyme Inhibitors

Introduction: The aim of this study was to investigate the effects of plasma and tissue angiotensin-converting enzyme inhibitors (ACE-Is) against propofol-induced endothelial dysfunction and to elucidate the involved mechanisms in vitro. Materials and methods: We examined the effects of propofol (50 μM), quinaprilat and enalaprilat (10−5 M) on fibrinolysis (t-PA, PAI-1, TAFI antigen levels), oxidative stress parameters (H2O2 and MDA antigen levels and SOD and NADPH oxidase mRNA levels) and nitric oxide bioavailability (NO2/NO3 concentration and NOS expression at the level of mRNA) in human umbilical vein endothelial cells (HUVECs). Results: We found that both ACE-Is promoted similar endothelial fibrinolytic properties and decreased oxidative stress in vitro. Propofol alone increased the release of antifibrinolytic and pro-oxidative factors from the endothelium and increased mRNA iNOS expression. We also found that the incubation of HUVECs in the presence of propofol following ACE-Is pre-incubation caused weakness of the antifibrinolytic and pro-oxidative potential of propofol and this effect was similar after both ACE-Is. Conclusions: This observation suggests that the studied ACE-Is exerted protective effects against endothelial cell dysfunction caused by propofol, independently of hemodynamics.

Abstract P423: Chronic Doxycycline Administration Inhibits Angiotensin Converting Enzyme Activity and Exerts Antioxidants Effects in Renovascular Hypertensive Rats

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Elen Rizzi Sanchez ◽  
Giselle F Bonacio ◽  
Danielle A Guimaraes ◽  
Gustavo Oliveira Paula ◽  
Jefferson Henrich Amaral ◽  
...  
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Cardiovascular Effects ◽  
Angiotensin Converting Enzyme Inhibitors ◽  
Converting Enzyme ◽  
Hypertensive Rats ◽  
Angiotensin I ◽  
Converting Enzyme Inhibitors ◽  
Ace Activity

Doxycycline (Dox), an established matrix metalloproteinase (MMP) inhibitor, and angiotensin-converting enzyme inhibitors (ACEi) present beneficial cardiovascular effects which could be consequence of their antioxidants properties. Furthermore, some evidences have shown other biochemical similarities between Dox and ACEi suggesting that Dox could also inhibit ACE and ACEi directly interact with MMPs and inhibit these proteases. Supporting this idea, Dox is able to chelate divalent metals, such as calcium and zinc, which are essential for the ACE activity. In this regard, we hypothesized that Dox inhibits ACE activity in hypertensive rats which leads to a reduction in ROS production and decrease hypertension. Sham-operated or 2K1C hypertensive rats were treated with Dox (30 mg/Kg/day) or water for 4 weeks. Systolic blood pressure (SBP) was monitored weekly. Dox treatment reduced SBP in 2K1C rats from 200±12 mmHg to 158±8 mmHg (P<0.05). In addition, Dox treatment attenuated reactive oxygen species (ROS) levels in hypertensive animals measured by lucigenin chemiluminescense (in RLU/mg of aorta: from 711±1.0 to 377±93; P<0.05). ACE activity in aorta was increased in untreated 2K1C rats (22±0.8 nmols/min/g) when compared with the Sham group (12±1.0 nmols/min/g; P<0.05) and Dox treatment was able to reduce ACE activity in 2K1C rats (15±2.0 nmols/min/g; P<0.05). To evaluate whether Dox inhibits ACE activity in vitro , aortic tissues from 2K1C rats were incubated with Dox or Captopril (a known ACEi ). Dox in vitro did not affect ACE activity while captopril inhibited 80% of its activity. To verify whether Dox could inhibit ACE activity in vivo , an acute assay was performed with different doses of angiotensin I (in μg/Kg: 0.03, 0.3 and 3), after the single administration of Dox or saline (i.p.). Angiotensin I infusion increased mean arterial pressure dose-dependently and Dox pretreatment did not attenuated these increases significantly (P>0.05) as Captopril.Taken together, these results show that chronic treatment with Dox inhibits ACE activity in aorta of 2K1C rats, which contribute to ROS reduction and SBP attenuation. However, the mechanism by which Dox inhibits ACE activity needs further investigation.

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