Correlation between anti-hypertensive activity in rats and plasma angiotensin I-converting enzyme (ACE) inhibition in mice following oral administration of ACE inhibitors

1985 ◽  
Vol 17 (4) ◽  
pp. 331-344
Author(s):  
S.F. Pong ◽  
R.R. Brooks ◽  
C.T. Huang ◽  
A.F. Moore
1984 ◽  
Vol 62 (1) ◽  
pp. 116-123 ◽  
Author(s):  
Ernesto L. Schiffrin ◽  
Jolanta Gutkowska ◽  
Gaétan Thibault ◽  
Jacques Genest

The angiotensin I converting enzyme (ACE) inhibitor enalapril (MK-421), at a dose of 1 mg/kg or more by gavage twice daily, effectively inhibited the pressor response to angiotensin I for more than 12 h and less than 24 h. Plasma renin activity (PRA) did not change after 2 or 4 days of treatment at 1 mg/kg twice daily despite effective ACE inhibition, whereas it rose significantly at 10 mg/kg twice daily. Blood pressure fell significantly and heart rate increased in rats treated with 10 mg/kg of enalapril twice daily, a response which was abolished by concomitant angiotensin II infusion. However, infusion of angiotensin II did not prevent the rise in plasma renin. Enalapril treatment did not change urinary immunorcactive prostaglandin E2 (PGE2) excretion and indomethacin did not modify plasma renin activity of enalapril-treated rats. Propranolol significantly reduced the rise in plasma renin in rats receiving enalapril. None of these findings could be explained by changes in the ratio of active and inactive renin. Water diuresis, without natriuresis and with a decrease in potassium urinary excretion, occurred with the higher dose of enalapril. Enalapril did not potentiate the elevation of PRA in two-kidney one-clip Goldblatt hypertensive rats. In conclusion, enalapril produced renin secretion, which was in part β-adrenergically mediated. The negative short feedback loop of angiotensin II and prostaglandins did not appear to be involved. A vasodilator effect, apparently independent of ACE inhibition, was found in intact conscious sodium-replete rats.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Maira R. Segura-Campos ◽  
Fanny Peralta-González ◽  
Arturo Castellanos-Ruelas ◽  
Luis A. Chel-Guerrero ◽  
David A. Betancur-Ancona

Hypertension is one of the most common worldwide diseases in humans. Angiotensin I-converting enzyme (ACE) plays an important role in regulating blood pressure and hypertension. An evaluation was done on the effect of Alcalase hydrolysis of defattedJatropha curcaskernel meal on ACE inhibitory activity in the resulting hydrolysate and its purified fractions. Alcalase exhibited broad specificity and produced a protein hydrolysate with a 21.35% degree of hydrolysis and 34.87% ACE inhibition. Ultrafiltration of the hydrolysate produced peptide fractions with increased biological activity (24.46–61.41%). Hydrophobic residues contributed substantially to the peptides’ inhibitory potency. The 5–10 and <1 kDa fractions were selected for further fractionation by gel filtration chromatography. ACE inhibitory activity (%) ranged from 22.66 to 45.96% with the 5–10 kDa ultrafiltered fraction and from 36.91 to 55.83% with the <1 kDa ultrafiltered fraction. The highest ACE inhibitory activity was observed inF2 ( μg/mL) from the 5–10 kDa fraction andF1 ( μg/mL) from the <1 kDa fraction. ACE inhibitory fractions fromJatrophakernel have potential applications in alternative hypertension therapies, adding a new application for theJatrophaplant protein fraction and improving the financial viability and sustainability of a Jatropha-based biodiesel industry.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Joanna Sikora ◽  
Marlena Broncel ◽  
Elżbieta Mikiciuk-Olasik

Purpose. The aim of the study was to analyze the effects of two-month supplementation with chokeberry preparation on the activity of angiotensin I-converting enzyme (ACE) in patients with metabolic syndrome (MS). During thein vitrostage of the study, we determined the concentration of chokeberry extract, which inhibited the activity of ACE by 50% (IC50).Methods. The participants (n=70) were divided into three groups: I—patients with MS who received chokeberry extract supplements, II—healthy controls, and III—patients with MS treated with ACE inhibitors.Results. After one and two months of the experiment, a decrease in ACE activity corresponded to 25% and 30%, respectively. We documented significant positive correlations between the ACE activity and the systolic (r=0.459,P=0.048) and diastolic blood pressure, (r=0.603,P=0.005) and CRP. The IC50of chokeberry extract and captopril amounted to155.4±12.1 μg/mL and0.52±0.18 μg/mL, respectively.Conclusions. Ourin vitrostudy revealed that chokeberry extract is a relatively weak ACE inhibitor. However, the results of clinical observations suggest that the favorable hypotensive action of chokeberry polyphenols may be an outcome of both ACE inhibition and other pleotropic effects, for example, antioxidative effect.


2009 ◽  
Vol 390 (9) ◽  
Author(s):  
Carlos Eduardo L. Cunha ◽  
Helena de Fátima Magliarelli ◽  
Thaysa Paschoalin ◽  
Aloysius T. Nchinda ◽  
Jackson C. Lima ◽  
...  

Abstract Dipeptidyl carboxypeptidase from Escherichia coli (EcDcp) is a zinc metallopeptidase with catalytic properties closely resembling those of angiotensin I-converting enzyme (ACE). However, EcDcp and ACE are classified in different enzyme families (M3 and M2, respectively) due to differences in their primary sequences. We cloned and expressed EcDcp and studied in detail the enzyme's S3 to S1′ substrate specificity using positional-scanning synthetic combinatorial (PS-SC) libraries of fluorescence resonance energy transfer (FRET) peptides. These peptides contain ortho-aminobenzoic acid (Abz) and 2,4-dinitrophenyl (Dnp) as donor/acceptor pair. In addition, using FRET substrates developed for ACE [Abz-FRK(Dnp)P-OH, Abz-SDK(Dnp)P-OH and Abz-LFK(Dnp)-OH] as well as natural ACE substrates (angiotensin I, bradykinin, and Ac-SDKP-OH), we show that EcDcp has catalytic properties very similar to human testis ACE. EcDcp inhibition studies were performed with the ACE inhibitors captopril (K i=3 nm) and lisinopril (K i=4.4 μm) and with two C-domain-selective ACE inhibitors, 5-S-5-benzamido-4-oxo-6-phenylhexanoyl-L-tryptophan (kAW; K i=22.0 μm) and lisinopril-Trp (K i=0.8 nm). Molecular modeling was used to provide the basis for the differences found in the inhibitors potency. The phylogenetic relationship of EcDcp and related enzymes belonging to the M3 and M2 families was also investigated and the results corroborate the distinct origins of EcDcp and ACE.


Sign in / Sign up

Export Citation Format

Share Document