Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.15.1 (ACE)
18,300 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dipeptide and tripeptide derivatives containing a statine residue were synthesized as inhibitors of human renin. ES-305, bis[(1-naphthyl)methyl]acetyl(BNMA)-histidyl-statine 2(S)-methylbutylamide was found to be a highly potent inhibitor of human renin with a Ki value of 1.7 X 10(-9) M. Dipeptide derivatives with the BNMA group at the N-terminal (BNMA-Val-Sta-isoleucinol [ES-313], BNMA-Leu-Sta-isoleucinol [ES-316], and BNMA-Nle-Sta-isoleucinol [ES-317]) had potencies against human renin that were similar to the potency of ES-305. All these dipeptide derivatives competitively inhibited human renin. The inhibitors were also potent against monkey renin but were less effective against renins from pig, goat, dog, rabbit, and rat. ES-305 had little effect on cathepsin D and pepsin at the concentration of 10(-5) M. The other derivatives showed detectable inhibition of cathepsin D (IC50, 10(-6) - 10(-7) M) and pepsin (10(-5) - 10(-6) M). All the compounds had little or no effect on trypsin, chymotrypsin, angiotensin converting enzyme, and urinary kallikrein at the concentration of 10(-5) M. Our results indicate that ES-305 is a highly potent and specific inhibitor of human renin. This compound is superior to other, previously described statine-containing renin inhibitors with respect to molecular size and enzyme specificity.
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PMID:Statine-containing dipeptide and tripeptide inhibitors of human renin. 308 74

An orally active renin inhibitor, ES 6864 (N-[(2R)-3-morpholinocarbonyl-2-(1-naphthylmethyl)propionyl]-(4- thiazolyl)-L-alanyl-cyclostatine-(2-morpholinoethyl)amide), was synthesized. ES 6864 was found to be a highly potent inhibitor of human renin with a Ki value of 7.3 x 10(-9) M. The compound competitively inhibited human renin. The inhibitor was also potent against monkey renin but was less effective against renins from pig, goat, dog, rabbit, and rat. ES 6864 did not inhibit cathepsin D, pepsin, trypsin, chymotrypsin, angiotensin converting enzyme, and urinary kallikrein at a concentration of 10(-5) M. ES 6864 was resistant to proteolytic actions of the enzymes in rat tissue homogenates (liver, kidney, pancreas, and small intestine). Oral administration of ES 6864 at 30 mg/kg to conscious, sodium-depleted marmosets produced a significant blood pressure reduction and almost complete inhibition of plasma renin activity, which persisted for 5 hours. Oral administration of ES 6864 also produced dose-related decreases of blood pressure in hog renin-infused rats, but the duration of action was much shorter than that in conscious marmosets. The parent compound in the blood following oral administration of ES 6864 to marmosets was confirmed directly by measuring the plasma concentration of ES 6864. These results enhance the possibility of developing renin inhibitors that can be used clinically.
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PMID:A highly potent and long-acting oral inhibitor of human renin. 313 6

The antihypertensive efficacy of angiotensin converting enzyme (ACE) inhibitors may result from the blockade of angiotensin II formation but also, theoretically, from the inhibition of kinin breakdown. To test whether a blunted activity of the kallikrein-kinin system might account for the failure of ACE inhibitors in lowering blood pressure (BP) in patients in whom the renin-angiotensin system (RAS) is not enhanced, 31 essential hypertensives with normal or low plasma renin activity (PRA) were evaluated before and after a single oral dose (50 mg) of captopril. A significant fall, in both systolic and diastolic BP, was obtained in the subgroup of patients who were classified as 'normal-kallikrein hypertensives' according to whether their pretreatment urinary kallikrein excretion was within the normal range, while no significant change in BP was observed in 'low-kallikrein hypertensives'. Furthermore, the mean percentage fall in mean BP, throughout the 2 h following captopril administration, was significantly related to the basal value of urinary kallikrein excretion (r = 0.47, P less than 0.05) in all the patients. Our results suggest that blunted activity of the kallikrein system might be responsible for failure of captopril to lower BP in some hypertensive patients.
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PMID:Role of renal kallikrein in modulating the antihypertensive effect of a single oral dose of captopril in normal- and low-renin essential hypertensives. 332 16

The antihypertensive efficacy of ACE inhibitors depends in theory from the blockade of the angiotensin II formation but also from the inhibition of kinin breakdown. To test whether a blunted activity of the kallikrein-kinin system might account for the failure of ACE inhibitors in lowering BP in patients in whom the renin-angiotensin system is not enhanced, thirty-one essential hypertensives with normal or low PRA were evaluated before and after a single oral dose (50 mg) of captopril. A significant fall both in systolic and diastolic blood pressure (BP) was obtained in the subgroup of patients who were classified as "normal kallikrein hypertensives" according to whether their pretreatment urinary kallikrein excretion was within the normal range, while no significant change in BP was observed in "low kallikrein hypertensives". Furthermore the mean percentage fall in mean BP, throughout the 2 hours following captopril administration, was significantly related to the basal value of urinary kallikrein excretion (r = 0.47, p less than 0.05) in the entire group of patients. Our results suggest that a blunted activity of the kallikrein system might be responsible for failure of captopril in lowering BP in patients in whom the renin-angiotensin system is not pathogenetically implicated.
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PMID:Urinary kallikrein excretion can predict the blood pressure response to a single oral dose of captopril. 332 15

Previous studies of the renal kallikrein-kinin system in chronic renal failure (CRF) have given conflicting results. We have assessed activity of this vasoactive hormone system in CRF and investigated a possible relationship to hypertension in patients with CRF: 24-hour urinary kallikrein excretion (UKa) was measured in 22 patients with CRF (9 normotensive and 13 hypertensive) and 11 healthy controls. Age, sex, urine volume, and urinary sodium excretion were similar in each group. Compared with controls, UKa was reduced in both normotensive and hypertensive patients with CRF, with no difference between CRF groups. The reduction in UKa in CRF was less than the reduction in glomerular filtration rate (GFR), as assessed by endogenous creatinine clearance (CCr). When UKa was divided by CCr, UKa/mL CCr was therefore increased, to a similar extent, in both normotensive and hypertensive patients with CRF. This suggests that release of renal kallikrein from functioning nephrons is increased in CRF. The results do not support a role for deficient kallikrein release in the genesis of hypertension in CRF, as previously suggested; however, these abnormalities could be relevant to other aspects of renal function in CRF. The converting-enzyme inhibitor, captopril, was given to 5 patients with CRF, hypertension, and low UKa. Introduction of captopril was followed by a further reduction in UKa in all subjects. Captopril is known to inhibit kininase II, the principal enzyme involved in degradation of kinins; this potentiating effect may be counteracted by a reduction in renal kallikrein release and hence in kinin generation.
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PMID:Urinary kallikrein excretion in chronic renal failure: relationship to blood pressure and the acute effect of captopril. 333 25

Responses in urinary kallikrein and kinin excretion and systolic blood pressure to MK 421, SA 446 or captopril were studied in normotensive rats fed on a regular or a low sodium diet to assess the role of renal kallikrein-kinin system in their hypotensive effect. MK 421, SA 446 or captopril were infused at a rate of 6 mg/kg/day by osmotic minipump implanted intraperitoneally for up to 6 days. The magnitude of fall in systolic blood pressure was greater on a low sodium diet when compared to on a regular diet, whereas the pattern of the fall was similar on both diets. The magnitude of falls in plasma angiotensin II and aldosterone concentration induced by MK 421, SA 446 and captopril was not significantly different between both regular and low sodium diets. Urinary kallikrein and kinin excretion and sodium excretion were increased during infusion of MK 421, SA 446 or captopril on a low sodium diet, however any significant changes were not found in each of them on a regular diet. The present results suggest that on a low sodium diet the augmented hypotensive response to angiotensin converting enzyme inhibitors in the rats might be due to the enhanced renal kallikrein-kinin system in addition to suppressed renin-angiotensin system.
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PMID:Renal kallikrein-kinin system and the depressor effect of angiotensin converting enzyme inhibitors MK 421, SA 446, and captopril in rats. 608 84

The efficacy and tolerability of the new ACE-inhibitor enalapril (MK 421) and the beta 1-selective adrenoceptor blocker atenolol for the treatment of primary hypertension were compared in a double blind parallel study. 12 patients were randomized to each drug. The doses of enalapril were 20 and 40 mg o.d. and of atenolol 50 and 100 mg o.d. for 4 weeks each, whereafter hydrochlorothiazide (HCTZ) 25 or 50 mg o.d. was added if necessary to achieve a supine diastolic blood pressure (BP) less than 90 mm Hg 24 hours after drug intake. Supine BP was reduced from 160 +/- 7/111 +/- 4 mm Hg to 153 +/- 13/101 +/- 9 mm Hg (p less than 0.05/p less than 0.005) with enalapril and from 163 +/- 17/109 +/- 6 mm Hg to 145 +/- 11/95 +/- 7 mm Hg (p less than 0.005/p less than 0.001) with atenolol. The addition of HCTZ caused a profound additive BP reduction to 132 +/- 7/88 +/- 6 mm Hg with enalapril and to 130 +/- 10/88 +/- 7 mm Hg with atenolol. There was no significant difference between the efficacy of enalapril and atenolol alone or combined with HTCZ. The reduction in mean arterial pressure with enalapril tended to correlate with pre-treatment stimulated plasma renin activity and 24 hours urinary kallikrein excretion. Both drugs tended to reduce serum and urinary aldosterone and kallikrein excretion to the same extent. There was one drop-out in each group, one due to impotence on the combination of enalapril and HCTZ and one due to peripheral coldness during atenolol treatment. Other side effects were mild. No toxic adverse effects were registered.
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PMID:Enalapril and atenolol in primary hypertension--a comparative study of blood pressure lowering and hormonal effects. 608 25

In order to investigate the role of the renal kallikrein-kinin (K-K) system in normal (NRH) and low renin (LRH) subgroups of essential hypertension (EHT), daily excretions of urinary kallikrein (KAL) quantity and activity, kinin (KIN), total and pre-KAL, and kininase I and II were measured in 21 normotensives (NT), 29 patients with NRH and 16 patients with LRH. The daily excretions of both KAL quantity and activity, total and pre-KAL, and KIN were significantly lower in NRH and LRH than in NT. That of kininase I was significantly higher in NRH and LRH than in NT, but that of kininase II was not. In comparing NRH and LRH, the urinary excretions of KAL activity and KIN were lower in LRH than in NRH, and that of kininase I was higher in LRH than in NRH. The KAL/total KAL ratio did not show any significant difference among NT, NRH and LRH. These findings suggest that the suppression of the renal K-K system in EHT seems to be due to both the decrease of KAL through the pre-KAL synthesis in the kidney and an increase of kininase I activity, but not to the inhibition of conversion from pre-KAL to active KAL and the more obvious suppression of this system in LRH than in NRH may be partly explained by KAL inhibitors and/or increased kininase I activity.
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PMID:Study on the renal kallikrein-kinin system in normal and low renin subgroups of essential hypertension. 610 Jul 42

Angiotensin-converting enzyme kininase II reduces bradykinin metabolism in vitro and in vivo. However, consistent changes in circulating bradykinin levels after the angiotensin-converting enzyme inhibitor captopril have not been reported. The kallikrein-kinin system has been suggested to be a local hormonal system concerned with regional blood flow, and hence circulating levels may not reflect local tissue levels of kinins. Anesthetized dogs given captopril had a significant increase in urinary kinin excretion without a change in circulating bradykinin levels or in urinary kallikrein. These changes in renal kinins were accompanied by a decrease in blood pressure and renal vasodilation. The hypotension and renal vasodilation produced by captopril were not attenuated either by pretreatment with the angiotension receptor antagonist Sar1-Ileu8-angiotensin II or by reduction of endogenous prostaglandin production with indomethacin. Postischemic renal vasodilation after temporary renal artery occlusion was also associated with increased urinary kinin levels. These results demonstrate that captopril effectively inhibits renal angiotensin-converting enzyme and that the renal kallikrein-kinin system may play an important role in regulating the renal vasculature and may contribute to the renal hemodynamic effects of captopril. Many polypeptide hormone membrane receptors are self-regulated by endogenous tissue concentrations of the peptide hormone. Infusions of bradykinin into rats reduced specific bradykinin receptors. A similar decrease in bradykinin receptor numbers without change in receptor affinity was demonstrated after captopril administration. These results provide indirect evidence that angiotensin-converting enzyme/kininase inhibition by captopril increases local tissue concentration of kinins, which may contribute to the hypotensive effect.
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PMID:Effect of angiotensin-converting enzyme inhibition on circulating and local kinin levels. 612 71

The role of kinins in the acute antihypertensive effect of a converting enzyme inhibitor (CEI) was studied in sodium-depleted normotensive and in two-kidney, one clip chronically hypertensive rats (2K-1C). The 2K-1C were on a normal sodium diet. The acute vasodepressor effect of the CEI was determined in these two groups either after administration of normal rabbit globulins or antikinin globulins. The amount of kinin antibodies administered completely blocked the hypotensive effects of bradykinin, 400 ng/kg, and urinary kallikrein, 4 microgram/kg. After administration of CEI in the sodium-depleted rats there was no significant difference (p greater than 0.05) in the acute changes in mean blood pressure (BP) between the group pretreated with normal rabbit globulins (delta BP -32.3 +/- 3.9 mm Hg) and the group pretreated with antikinin globulins (delta BP -25 +/- 2.5 mm Hg). In the 2K-1C pretreated with normal rabbit globulins, the CEI produced a decrease in BP of -21 +/- 4.5 mm Hg. This decrease was almost completely blocked in the group pretreated with the antikinin globulins (delta BP -4 +/- 4.1 mm Hg). These differences in the changes in BP were significant (p less than 0.02). These results suggest that the acute antihypertensive effect of the CEI in the sodium-depleted rats is probably due to inhibition of the conversion of angiotensin I to II while in the 2K-1C it is due, in part, to an increase in kinin concentrations secondary to the inhibition of kininase II.
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PMID:Role of kinins in the acute antihypertensive effect of the converting enzyme inhibitor, captopril. 625 58


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