Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.23.15 (renin)
 35,795 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The relation of plasma renin activity (PRA) and plasma levels of angiotensin I (AI) and II (AII) to those of various proteases, including eight endopeptidases and four aminopeptidases, was investigated in 51 normal control subjects. The multivariate study using factor analysis showed that the plasma proteases can be classified into three main components: the aminopeptidase, the plasmin, and the kinin-kallikrein. PRA and AI were related almost exclusively to the aminopeptidase component, while the AII level was related not only to the same component but also to the kallikrein-kinin component. This kind of multivariate study may help in the elucidation of the role of proteases and bioactive peptides, such as angiotensin derivatives, in essential hypertension through a comparison of multivariate relationships in controls and patients.
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PMID:Three main components in plasma proteases and their relation to the renin-angiotensin system. 219 54

Twenty-seven children [2 with chronic renal failure (CRF)] with reflux or obstructive nephropathy underwent intravenous urography with iopamidol 370, a nonionic contrast medium 1 (CM), osmolality 796 mosmol/kg, for renal growth evaluation. Mean iopamidol dosing was 1.69 ml/kg (range 1.22-2.42); the 2 children with CRF received 2 and 2.42 ml/kg respectively. One hour after infusion a significant decrease in haematocrit, haemoglobin, plasma sodium (Na+), chloride (Cl-), renin activity and aldosterone was observed, consistent with a possible plasma volume expansion due to the slightly hypertonic CM. At the same time there was a significant increase in fractional excretion of Na+, Cl- and potassium, probably due to the haemodynamic effects and tubular response to a substance acting as on osmotic diuretic. The -24 to +48 h monitoring of albuminuria, beta-2-microglobulin excretion, and in 4 children excretion of N-acetyl-beta-glucosaminidase and alanine-aminopeptidase did not show any relevant nephrotoxicity. No untoward effect of clinical relevance was observed.
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PMID:Intravenous urography with iopamidol in children with reflux and obstructive nephropathy: effects on glomerular and tubular functions and the renin-angiotensin-aldosterone system. 220 71

Rats of the Milan Hypertensive Strain (MHS) may be considered a useful model for understanding the genetic molecular mechanism underlying a primary form of hypertension in at least a subgroup of patients. Many differences between MHS and its normotensive control strain (MNS) were found at the organ, cellular and biochemical level. In the present investigation renal cell membrane proteins (BBMV) were analysed by two-dimensional electrophoresis and a difference between MHS and MNS was shown in a polypeptide of 32 kDa, subsequently identified as the C-terminal fragment of aminopeptidase M (APM). The activity of the enzyme was higher in MHS. Genetic relationships between this enzyme and the other biochemical cellular abnormalities of MHS, namely sodium transport in BBMV and renin activity in kidney cortex were investigated in MHS, MNS and in two inbred recombinant strains. This analysis showed that faster sodium transport, low kidney levels of renin and hypertension, but not differences in two-dimensional electrophoretic pattern and in aminopeptidase M activity, cosegregated in recombinant strains. These results are consistent with the hypothesis that the faster sodium transport can be considered a primary cellular abnormality responsible for hypertension in MHS and that the aminopeptidase difference is not involved in the cellular abnormalities.
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PMID:Relationships among alterations in renal membrane sodium transport, renin and aminopeptidase M activities in genetic hypertension. 810 53

One of the characteristics of early diabetic nephropathy is glomerular hyperfiltration and hyperperfusion. Many factors have been suggested to induce glomerular hyperperfusion among which are an increased production of vasodilatory prostanoids, an increased synthesis of nitric oxide, a reduced responsiveness of afferent glomerular arterioles to vasoconstrictor stimuli due to diabetic metabolic disturbances and a decreased receptor density for angiotensin II. It has been known for years that angiotensin II is formed locally due to the local activation of the renin angiotensin system. The local angiotensin II concentration, however, is not only regulated by the synthesis rate but also by the local degradation through activation of an aminopeptidase. The main finding of the present study was that the mRNA expression and activity of the angiotensin II degrading enzyme, angiotensinase A, was increased twofold in diabetic rats at 5 weeks and that the increase in mRNA expression was suppressed by insulin therapy and short-term treatment with the angiotensin II antagonist saralasin, whereas angiotensinase A enzyme activity was only reduced by saralasin and not by insulin. These results demonstrate that the angiotensin II degrading exopeptidase angiotensinase A is activated in diabetic glomeruli. This increased activity may be an additional mechanism to explain glomerular hyperfiltration and hyperperfusion in early diabetic nephropathy.
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PMID:Angiotensinase A gene expression and enzyme activity in isolated glomeruli of diabetic rats. 872 72

In the last decade, two types of genes participating in the etiology of hypertension have been identified. The primary genes or blood pressure regulators are those that codify enzymes (renin, kallikrein, kininase, aminopeptidase), hormones (angiotensins, vasopressin, aldosterone, prostaglandins, and atrial natriuretic peptide) and substrates (angiotensinogen and kininogen). They cause arteriolar vasodilation or vasoconstriction or sodium retention in the extravascular space. Allelic polymorphisms associated to essential hypertension have been described. The secondary genes are those that produce hereditary diseases of low prevalence, associated to hypertension in 20 to 80% of patients (polycystic kidney disease, pheochromocytoma, adrenal hyperplasia, hereditary nephritis). Forty genes located in all chromosomes, that are dominantly, recessively or X-linked transmitted, have thus far been identified. Chromosomal maps with all genic loci are presented.
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PMID:[The genes of human hypertension]. 946 Feb 75

Although there is a brain renin-angiotensin system, its mechanisms of control are not fully understood. We studied the effect of oral administration of the AT(1) receptor antagonist losartan on brain aminopeptidase (AP) activity, which plays a major role in neuropeptide metabolism. Six AP activities, related and non-related with the angiotensin (Ang) metabolism, were measured in their soluble and membrane-bound forms in the frontal cortex of control animals and rats treated with losartan, chronically administered via the drinking water. The results demonstrate that soluble pGluAP and membrane-bound AspAP and GluAP increased significantly in losartan-treated animals, indicating that the blockade of the AT(1) receptor stimulates the activity of AP involved in the Ang metabolism. Moreover, the blockade of the AT(1) receptor induces changes not only in the brain angiotensin metabolism, but probably also in that of other neuropeptides.
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PMID:Oral administration of losartan influences aminopeptidase activity in the frontal cortex. 1087 10

The intake of mono- and polyunsaturated fatty acids has been associated with a minor risk of cardiovascular diseases including hypertension. Changes in levels of fatty acids may also modify the cell activity and may be related with alterations in different regulatory processes. Aminopeptidases are zinc-metalloenzymes which metabolise circulating peptide hormones in several tissues. Glutamyl-aminopeptidase (GluAP) and to a lesser extent, aspartyl-aminopeptidase (AspAP), are related with angiotensin metabolism in the renin-angiotensin system. The present work was designed to study the effect of a range of concentrations (1-100 microM) of oleic and linoleic acids and cholesterol present in the culture medium on the activity of GluAP and AspAP in the culture of rat cerebral cortical astrocytes taken from 21-day-old fetuses. The results showed that oleic acid inhibits, while linoleic acid stimulates the activity of AspAP. Both fatty acids inhibit the activity of GluAP. Cholesterol stimulates the activity of both enzymes. On the basis of these results, a functional link may exit between the effects of fatty acids on hypertension and the modulation of aminopeptidase activity by these compounds in rat astrocytes, as an example of target cell type in the central nervous system.
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PMID:Oleate, linoleate and cholesterol differently modify aspartyl- and glutamyl-aminopeptidase activities in primary cultures of rat astrocytes. 1116 79

Given that the existence of a local renin-angiotensin system (RAS) in the pituitary and its participation in the regulation of blood pressure and other biological functions are widely accepted, the aim of this work is to analyze the influence of dietary cholesterol on the activity of the enzymes involved in the metabolism of the effector peptides of the renin-angiotensin system (angiotensin II and III) and vasopressin, in the pituitary of male and female mice fed on a cholesterol-enriched diet (1% cholesterol and 0.5% cholic acid). Soluble and membrane-bound pituitary aminopeptidase A (aspartyl- and glutamyl-aminopeptidase), aminopeptidase M (alanyl-aminopeptidase), aminopeptidase B (arginyl-aminopeptidase) and cystinyl-aminopeptidase activities were fluorimetrically measured. In female mice, cholesterol-enriched diet produced a significant increase in soluble aspartyl- and membrane-bound aspartyl- and glutamyl-aminopeptidase activities, and a significant decrease in membrane-bound alanyl-, arginyl- and cystinyl-aminopeptidase activities. In male mice, after feeding the diet, a significant increase in soluble glutamyl- and membrane-bound arginyl-aminopeptidase activities was observed. Our results indicate differential effects of dietary cholesterol on the metabolism of angiotensin II and III and vasopressin in the pituitary of male and female mice.
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PMID:Pituitary aminopeptidase activities involved in blood-pressure regulation are modified by dietary cholesterol: sex differences. 1173 Sep 80

Although hypercholesterolemia and hypertension have been extensively associated, the regulatory mechanism underlying this relationship is poorly understood. Systemic and local renin-angiotensin systems are involved in the control of blood-pressure. Angiotensin II has been considered as the main effector peptide of renin-angiotensin system. However, other peptides derived from the metabolism of angiotensin II, as angiotensins III and IV have been shown to play significant roles. The aim of this study is to analyse the effect of dietary cholesterol on the activity of the enzymes involved in the metabolism of angiotensins II and III. Soluble and membrane-bound aminopeptidase A (aspartyl- and glutamyl-aminopeptidases), B (arginyl-aminopeptidase) and M (alanyl-aminopeptidase) activities were measured in the frontal cortex of male and female mice fed a cholesterol enriched-diet (1% cholesterol; 0.5 cholic acid). Soluble and membrane-bound aminopeptidases B and M did not change in male or female cholesterol groups. Significant increases were observed in membrane-bound aspartyl- and glutamyl-aminopeptidase activities in both cholesterol groups. Soluble aspartyl- and glutamylaminopeptidases did not change in male cholesterol group, but significant decreases were detected in female cholesterol group. Our results may indicate that the metabolism of angiotensin II to angiotensin III by aminopeptidase A is increased, but angiotensin III metabolism by aminopeptidases B and M is not modified after cholesterol intake; so cholesterol may enhance the effects of angiotensin III, at least, at the cortical level.
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PMID:Differential effects of dietary cholesterol on aminopeptidase A, B and M in the frontal cortex of male and female mice. 1184 65

The autocrine/paracrine control mechanisms of local factors, such as the renin-angiotensin system and the thyrotropin-releasing hormone (TRH), seem to play a relevant role in testicular physiology. It has been proposed that dietary fat composition influences male reproductive function modifying the cholesterol-phospholipid composition of testicular plasma membranes. Modifications in the composition and physical properties of the membranes may lead to alterations in the activities of membrane-bound (M-B) enzymes. We have previously demonstrated that cholesterol and steroid hormones affect aminopeptidase (AP) activities. Dietary fatty acids with different degrees of saturation modified AP activities in the serum of mice and an olive oil supplemented diet influenced the AP activities in the testes of mice. We hypothesized that the modification of dietary fat composition may affect angiotensin- [glutamyl-AP (GluAP), aspartyl-AP (AspAP)] and TRH- [pyroglutamyl-AP (pGluAP)] degrading activities in the testis. In this study, we investigated the effect of diets supplemented with sunflower oil (SFO), fish oil (FO), olive oil (OO), lard (L) or coconut oil (CO) on soluble (Sol) and M-B GluAP, AspAP and pGluAP in mice testis, using arylamides as substrates. Sol GluAP activity did not show differences among groups. However, Sol AspAP and Sol pGluAP progressively decreased with the degree of saturation of the fatty acid used in the diet. In contrast, M-B GluAP progressively increased with the degree of saturation of the fatty acid used in the diet. For M-B AspAP activity, mice fed diets containing FO showed significantly higher levels than those fed diets containing SFO, OO and L but not those containing CO. For M-B pGluAP activity, the highest levels were observed for mice fed diets containing FO and OO. The present data suggest that the type of fat used in the diet may influence the autocrine/paracrine functions of locally synthesized angiotensin peptides and TRH in the testis, and consequently may be important in male reproductive functions.
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PMID:Dietary fatty acid composition affects aminopeptidase activities in the testes of mice. 1190 61


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