Plasma angiotensin I and serum placental leucine aminopeptidase (P-LAP) in pre-eclampsia

1985 ◽  
Vol 236 (3) ◽  
pp. 165-172 ◽  
Author(s):  
S. Mizutani ◽  
H. Akiyama ◽  
O. Kurauchi ◽  
H. Taira ◽  
O. Narita ◽  
...  
Keyword(s):  
Leucine Aminopeptidase ◽  
Angiotensin I ◽  
Plasma Angiotensin ◽  
Aminopeptidase P

Construction of a novel asymmetric imidazole-cored AIE probe for ratiometric imaging of endogenous leucine aminopeptidase

2021 ◽  
Author(s):  
Xueyan Huang ◽  
Qian Lei ◽  
Shuai Huang ◽  
Hongliang Zeng ◽  
Bin Feng ◽  
...  
Keyword(s):  
Leucine Aminopeptidase ◽  
Aminopeptidase P ◽  
Ratiometric Imaging

We reported a rational strategy to deliberately construct the first asymmetric tetraarylimidazole-based AIE probe, integrating AIE behavior in synergy with ESIPT character to ratiometric imaging of endogenous LAP for the...

A prospective serial study of plasma angiotensin I converting enzyme in pregnancy

1980 ◽  
pp. 51-58
Author(s):  
J. J. N. Oats ◽  
Fiona Broughton Pipkin ◽  
E. M. Symonds
Keyword(s):  
Converting Enzyme ◽  
Angiotensin I ◽  
Angiotensin I Converting Enzyme ◽  
Plasma Angiotensin ◽  
In Pregnancy

Measurement of Plasma Renin Activity as a Valid Estimation of Plasma Angiotensin Status

1978 ◽  
Vol 15 (1-6) ◽  
pp. 250-252 ◽  
Author(s):  
J. E. Roulston ◽  
G. A. Macgregor ◽  
Theresa Adam ◽  
Nirmala D. Markandu
Keyword(s):  
Angiotensin Ii ◽  
Plasma Renin Activity ◽  
Plasma Renin ◽  
Renin Activity ◽  
Activity Measurement ◽  
Plasma Samples ◽  
Angiotensin I ◽  
Plasma Angiotensin ◽  
Rate Limiting

Measurement of plasma renin activity is widely used as an indirect assessment of plasma angiotensin II concentration. There has been some controversy over the validity of this assay as an estimate of circulating angiotensin II levels because, during the in vitro generation of angiotensin I by renin, over a period of time, substrate concentration may diminish to such an extent that it becomes rate-limiting, giving an artificially low reflection of angiotensin II levels. In this paper the initial angiotensin I concentration, that is the concentration before in vitro angiotensin I generation, has been compared with the corresponding plasma renin activity for 2752 individual plasma samples. A linear relationship was found between the initial angiotensin I concentration and the plasma renin activity below 60 ng ml−1 h−1. This indicates that, under the conditions of this assay, substrate does not appear to become rate-limiting except at exceedingly high levels of plasma renin activity. These results appear to provide further validation for the use of plasma renin activity measurement as a reflection of the concentration of circulating angiotensin II levels.

The Enzymatic Degradation of Angiotensin II Analogues by proteolytic enzyme in vitro

1972 ◽  
Vol 50 (2) ◽  
pp. 113-118 ◽  
Author(s):  
M. C. Carrara ◽  
D. Regoli ◽  
W. K. Park
Keyword(s):  
Amino Acids ◽  
Angiotensin Ii ◽  
Unnatural Amino Acids ◽  
Enzymatic Degradation ◽  
Leucine Aminopeptidase ◽  
Receptor Interaction ◽  
Angiotensin I ◽  
Peptide Receptor ◽  
Angiotensin Ii Analogues

Angiotensin II (ATII), angiotensin I (ATI), and Acpc analogues of ATII, 8-Achc-ATII, 8-D-Phe-ATII, and 8-Ala-ATII, were incubated in vitro with carboxypeptidase, chymotrypsin, and leucine-aminopeptidase in order to study the influence of unnatural amino acids (Acpc, Achc, and D-Phe) and of L-Ala on the activity of peptidases.Fragments occurring during the breakdown of peptides were demonstrated by paper chromatography in an ascending system.ATII and ATI are rapidly inactivated by carboxypeptidase and chymotrypsin, while the degradation by leucine-aminopeptidase is slower.Substitution of L-Phe with Acpc, Achc, D-Phe, or L-Ala in position 8 prevents the degradation by carboxypeptidase. Chymotrypsin degrades 3-Acpc-ATII and 5-Acpc-ATII but not 4-Acpc-ATII. The action of leucine-aminopeptidase is not influenced by substituting Acpc to each one of the first five amino acids composing the molecule of angiotensin.The possible implications of these findings for the peptide-receptor interaction is discussed.

The Effect of Captopril on Blood Pressure and Angiotensins I, II and III in Sodium-Depleted Dogs: Problems Associated with the Measurement of Angiotensin II after Inhibition of Converting Enzyme

1980 ◽  
Vol 58 (6) ◽  
pp. 445-450 ◽  
Author(s):  
J. J. Morton ◽  
M. Tree ◽  
J. Casals-Stenzel
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Fold Increase ◽  
Converting Enzyme ◽  
Angiotensin I ◽  
Active Inhibitor ◽  
Arterial Blood ◽  
Rapid Fall ◽  
Angiotensin Iii ◽  
Plasma Angiotensin

1. Changes in arterial blood pressure, blood angiotensin I, plasma angiotensin II and plasma angiotensin III were measured in conscious sodium—depleted dogs after infusion of captopril, an orally active inhibitor of converting enzyme. 2. Angiotensins II and III were measured after chromatography to remove angiotensin I, which increased in concentration after inhibition of converting enzyme and which interfered in the direct assay for angiotensin II. 3. Infusion of captopril at 20, 200, 2000 and 6000 μg h−1 kg−1, each for 3 h, produced a rapid fall in blood pressure and in concentration of angiotensin II. Angiotensin II was undetectable at 6000 μg h−1 kg−1 (mean pre-infusion value for all samples was 39 ± sd 15 pmol/I, n = 14) 4. The percentage fall in blood pressure correlated with the percentage fall in plasma angiotensin II (r = 0.65, P<0.001) 5. These results suggest that the initial fall in blood pressure may be mediated in part by the suppression of angiotensin II. 6. Blood angiotensin I concentration rose with each rate of infusion of drug to a maximum 16-fold increase at 6000 μg h−1 kg−1 (26−416 pmol/l). The rise in angiotensin I was inversely related to the fall in angiotensin II (r = −0.68, P<0.001)

Spontaneous change of human plasma angiotensin I converting enzyme isoelectric point

1983 ◽  
Vol 227 (2) ◽  
pp. 434-439 ◽  
Author(s):  
Joseph J. Lanzillo ◽  
Stevens Joanne ◽  
John Tumas ◽  
Barry L. Fanburg
Keyword(s):  
Human Plasma ◽  
Isoelectric Point ◽  
Converting Enzyme ◽  
Angiotensin I ◽  
Spontaneous Change ◽  
Angiotensin I Converting Enzyme ◽  
Plasma Angiotensin

Plasma Angiotensin I Determines the Rate of Angiotensin II Generation Even during ACE Inhibition

1988 ◽  
Vol 10 (6) ◽  
pp. 1295-1296
Author(s):  
J. Nussberger ◽  
L. Juillerat ◽  
V. Mooser ◽  
B. Waeber ◽  
P. Graf ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Ace Inhibition ◽  
Angiotensin I ◽  
Plasma Angiotensin

Simultaneous determinations of plasma oxytocin and serum placental leucine aminopeptidase (P-LAP) during late pregnancy

1982 ◽  
Vol 15 (3) ◽  
pp. 141-145 ◽  
Author(s):  
Shigehiko Mizutani ◽  
Hide Hayakawa ◽  
Haruyuki Akiyama ◽  
Harutake Sakura ◽  
Masataka Yoshino ◽  
...  
Keyword(s):  
Leucine Aminopeptidase ◽  
Late Pregnancy ◽  
Aminopeptidase P

scholarly journals Involvement of human plasma angiotensin I-converting enzyme in the degradation of the haemoregulatory peptide N-acetyl-seryl-aspartyl-lysyl-proline

1993 ◽  
Vol 296 (2) ◽  
pp. 373-378 ◽  
Author(s):  
K J Rieger ◽  
N Saez-Servent ◽  
M P Papet ◽  
J Wdzieczak-Bakala ◽  
J L Morgat ◽  
...  
Keyword(s):  
Human Plasma ◽  
Proteinase Inhibitors ◽  
Negative Regulator ◽  
Haematopoietic Stem Cell ◽  
Converting Enzyme ◽  
Angiotensin I ◽  
Rabbit Lung ◽  
Angiotensin I Converting Enzyme ◽  
Plasma Angiotensin ◽  
Metalloprotease Inhibitors

The degradation of N-Ac-Ser-Asp-Lys-Pro (AcSDKP), a negative regulator controlling the proliferation of the haematopoietic stem cell, by enzymes present in human plasma, has been investigated. Radiolabelled AcSD[4-3H]KP ([3H]AcSDKP, 1 mM) was completely metabolized in human plasma with a half-life of 80 min, leading exclusively to the formation of radiolabelled lysine. The cleavage of AcSDKP was insensitive to classical proteinase inhibitors including leupeptin, but sensitive to metalloprotease inhibitors. The degradation was completely blocked by specific inhibitors of angiotensin I-converting enzyme (ACE; kininase II; peptidyldipeptide hydrolase, EC 3.4.15.1), showing that the first step of the hydrolysis was indeed due to ACE. In dialysed plasma, the hydrolysis proceeded at only 17% of the maximal rate, whereas addition of 20 mM NaCl led to the recovery of the initial rate observed with normal plasma. Hydrolysis of AcSDKP by commercial rabbit lung ACE generated the C-terminal dipeptide Lys-Pro. Thus, ACE cleaves AcSDKP by a dipeptidyl carboxypeptidase activity. In fact the formation of Lys-Pro was observed when AcSDKP was incubated in human plasma in the presence of HgCl2. These results suggest that ACE is involved in the first limiting step of AcSDKP degradation in human plasma. The second step seems to be under the control of a leupeptin- and E-64-insensitive, HgCl2-sensitive plasmatic enzyme.

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