Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fawn-hooded (FH) rats develop low-renin hypertension which is preceded by a decrease in urinary kallikrein. We examined urinary excretion of active and inactive kallikrein in hypertensive FH male rats and matched animals of the ancestral, normotensive Wistar strain. To determine the effects of modulation of salt intake on the kallikrein profile, rats were given standard rat chow (0.39% NaCl), a low-salt diet (0.02% NaCl), or a high-salt diet (standard chow plus water with 1% NaCl). Control FH rats excreted less active kallikrein (p less than 0.02), had similar amounts of inactive kallikrein, and had a higher inactive/active kallikrein ratio (p less than 0.02) than control Wistar rats. Low salt intake increased active kallikrein 136% (p less than 0.002) and 54% (p less than 0.035) in FH and Wistar rats, respectively, but did not change the level of inactive kallikrein or the inactive/active kallikrein ratio. High salt intake had no effect on kallikrein excretion in either strain. Low salt intake did not change blood pressure in either strain in spite of significant changes in plasma renin activity, angiotensin II and active kallikrein excretion. The low urinary active kallikrein and the high inactive/active kallikrein ratio in FH rats do not appear to play a role in the established hypertension in the FH rat, since modulation of these parameters did not cause a significant change in the elevated blood pressure.
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PMID:Modulation of urinary kallikrein and plasma renin activities does not affect established hypertension in the fawn-hooded rat. 264 67

Urinary kallikrein excretion (UKE) was investigated in neurogenic hypertensive dogs for a period of 8 months. The animals were made hypertensive by sinoaortic denervation (SAD). Plasma catecholamine levels (PC), plasma renin activity (PRA), plasma aldosterone concentration (PAC) and urinary sodium excretion (UNa) were also measured. The onset of hypertension was associated with an increase in PC. UKE, measured by amidolytic and kininogenase activities, exhibited a very significant transient increase two and four weeks after SAD. Progressively, UKE significantly decreased below control values at the 16th and 32nd week. Since the month following SAD is characterized by an increase in sympathetic tone (as shown by high PC levels), the transient increase of UKE can be related to this high PC level; although this hypothesis is only supported by a positive relationship between these two parameters. The subsequent decrease in UKE appeared linked to diminished mineralocorticoid activity. Thus, the biphasic pattern of UKE observed in the study suggests that variations of UKE are more a consequence of hypertension than a pathogenic factor. Because UKE, which is of renal origin, is reduced at the end of the study period, this may also suggest possible renal dysfunctions in this model of hypertension.
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PMID:Urinary kallikrein excretion following chronic sinoaortic denervation in conscious dogs. 265 Sep 29

The mechanism of suppression of renal kallikrein activity in low renin essential hypertensive and renoparenchymal hypertensive patients was investigated in this study. From Sephadex G-200 column chromatography studies, a single kallikrein peak was observed in both kallikrein radioimmunoassay and kininogenase activity in all samples from normal subjects, low renin essential hypertensive and renoparenchymal hypertensive patients, and in purified kallikrein solution. The enzyme-specific activity around the kallikrein peak in all urine samples from each group was significantly lower than that in purified kallikrein, and a significantly lower specific activity was found in both patient groups than was found in normal subjects. Moreover, it was also recognized that the specific activity of kallikrein decreased in all cases with the increase of the molecular weight of kallikrein, and this tendency was observed more obviously in the low renin essential hypertensive and renoparenchymal hypertensive patients than in the normal subjects. These results suggest the presence of a kallikrein-specific inhibitor with a low molecular weight in human urine, although the possibility of a variant form of kallikrein cannot be excluded.
Hypertension 1989 Oct
PMID:Mechanisms of suppression of renal kallikrein activity in low renin essential hypertension and renoparenchymal hypertension. 267 59

Essential hypertension (EH) is frequently not only a coexistent, but a preexistent condition in type-II-diabetes mellitus (NIDDM). Possible reasons for this phenomenon include the presence of the insulin resistance/hyperinsulinaemia syndrome in EH, leading to sodium retention, stimulation of the sympathetic nervous system and impaired glucose tolerance. Another reason could be a defect in the kallikrein-kinin system (KKS) which is known to be involved in both the regulation of blood pressure and insulin sensitivity of peripheral tissues. The classical concept of the glandular KKS as being an endocrine system with circulating hormones causing increased renal and peripheral blood flow, hypotension and natriuresis has changed recently, since kallikrein-like activity or mRNA coding for tissue kallikreins were detected in various tissues including kidney, vascular wall and skeletal muscle. This led to the present view, that paracrine local actions of different tissue KKS on regional blood flow, local substrate metabolism and insulin action are probably more important than previously expected. A disorder in the activity of the renal KKS has been known to be present in both NIDDM and EH. Recent work yielded evidence, that skeletal muscle KKS is activated upon muscle work in metabolically healthy subjects, but not in NIDDM and not in the majority of patients with EH. This suppressed tissue KKS seems to be a common feature of EH and NIDDM and might be involved in the pathogenesis of insulin resistance, impaired glucose tolerance and hypertension.
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PMID:The kallikrein/kinin system in the pathogenesis of hypertension in diabetes mellitus. 269 48

The activity of the kallikrein-kinin, prostaglandin and cyclase systems was assessed in 117 patients with chronic pyelonephritis with and without arterial hypertension. Pyelonephritis is shown to be associated with a dysfunction of the pressor-depressor mechanisms examined, featuring a depression of vasodepressor reactions. Patients with normal, increased and depressed humoral parameters could be found in each study group, the changes being particularly marked in patients with chronic pyelonephritis, combined with arterial hypertension.
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PMID:[Function of the kallikrein-kinin and prostaglandin systems of the kidneys in patients with chronic pyelonephritis]. 271 90

In tissues rich in kallikrein, vasodilator kinins, acting as paracrine hormones, may play a role in the local regulation of blood flow. We studied the role of kinins in the regulation of blood flow in the rat submandibular gland using a kinin analogue with antagonistic properties, [DArg0]Hyp3-Thi5-8[DPhe7]bradykinin. When infused into the carotid artery (20 micrograms/min/rat), this antagonist blocked the effect of bradykinin (25-250 ng/kg, intracarotid injection) on glandular blood flow. In nephrectomized rats, the antagonist also blocked the increase in glandular blood flow caused by enalaprilat, a kininase II converting enzyme inhibitor. At a dose of 20 micrograms/min/rat, the antagonist produced no detectable change in basal glandular blood flow; however, at a higher dose (100 micrograms/min/rat), it caused a significant decrease (p less than 0.001). In eight of 10 rats, blood flow decreased by 75% or more; this effect was not blocked by the alpha-adrenergic receptor antagonist phentolamine. After antagonist infusion was stopped, blood flow returned toward normal. Sympathetic nerve stimulation of the gland induced vasoconstriction followed by poststimulatory vasodilatation. In rats displaying severe vasoconstriction after the antagonist, postsympathetic vasodilatation was abolished even when stimulation was performed after the antagonist infusion had been stopped and blood flow returned toward normal. Although a direct vasoconstrictor effect of the kinin antagonist cannot be completely ruled out, these data suggest that, in the rat submandibular gland, kinins may play a role in regulation of basal blood flow and vasodilatation after converting enzyme inhibitor or sympathetic stimulation.
Hypertension 1989 Jul
PMID:Role of kinin in regulation of rat submandibular gland blood flow. 273 39

The renin-angiotensin system (RAS) has long been perceived as basically humoral. Since recent findings in molecular biology extended this view to local, possibly independent, tissue-RAS, both the RAS and the kallikrein-kinin cascade are understood as mixed local-systemic interacting systems, which explains local and systemic effects of converting enzyme (CE) inhibitors well. The key enzyme of both systems, CE, catalyzes the activation of the vasopressor and possibly trophic peptide, angiotensin II, and also inactivates the vasodilatory and, according to our observations, cardioprotective bradykinin. Thus, it is consistent that CE-inhibitors lower blood pressure, reduce cardiac hypertrophy, improve metabolic state and attenuate arrhythmias, particularly in ischemic hearts. It is evident from animal experiments that the tight binding favours new oral CE inhibitors, such as ramipril, not only for prevention but also for treatment of tissue injuries due to hypertension or ischemia.
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PMID:[Pharmacologic modification of the converting enzyme--local and systemic effects on the heart and blood vessels]. 285 Jun 85

The intrarenal kallikrein-kinin system was studied during the acute phase of renovascular hypertension induced by renal artery constriction and during teprotide inhibition of kininase II in the dog. Kallikrein-like activity measured by both kininogenase and esterolytic assays, was increased during renal artery constriction (p less than 0.5) and (p less than 0.01). The administration of teprotide resulted in a further increase of renal cortical kallikrein-like activity and inhibited kininase II activity (p less than 0.01). Following the inhibition of kininase II, the plasma concentration of kininogen was also significantly decreased (p less than 0.01). These results suggest that kininase II inhibition may increase levels of intrarenal and plasma kinins and that decreased degradation of kinin peptides may contribute significantly to the acute hypertensive effect of teprotide.
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PMID:Intrarenal kallikrein-kinin activity in acute renovascular hypertension in dogs. 285 35

The influence of phenylephrine (PHE), methoxamine (MET) and ephedrine (EPH) on kininogen and prekallikrein level in plasma was investigated in male Wistar rats. Simultaneously the effect of these drugs on blood pressure was monitored. No changes in kininogenesis were observed during the hypertension period (2 h after ip injection). The significant decrease in kininogen level (by 20-30%) was found 4 h after PHE (5 mg/kg) or EPH (40 mg/kg) and 4-12 h after MET (40 mg/kg) injection. The reduction of kallikrein utilization, indicating an increase in prekallikrein level in plasma, was noted only after PHE (by 34%) or MET (by 44%) administration. Phentolamine (REG) in a dose of 20 mg/kg, which counteracted the hypertensive effect of investigated drugs, abolished the influence of these drugs on kininogen level. The results indicate that the hypertension induced by alpha-adrenoceptor agonists evokes the delayed activation of kininogenesis parallel to the secondary decrease in blood pressure. Such a reaction of kinin system seems to be related to primary alpha-adrenoceptor stimulation, not to the direct influence of hypertensive drugs on kinin system in rat plasma.
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PMID:Hypertensive drugs and plasma kinins in rats. 287 49

1. Spontaneously hypertensive rats (SHR) excrete less kallikrein in urine than Wistar-Kyoto rats (WKY) during the developmental phase of hypertension. The present study was designed to examine whether the urinary defect is related to abnormalities in the renal kallikrein content in this hypertensive model. 2. Active and total kallikrein were measured (amidolytic assay) in the renal cortex of newborn and 4-, 8- and 12-week-old SHR and age-matched WKY. Active and total kallikrein were also measured in urine at the same ages, except at birth. 3. Tissue active kallikrein was significantly lower in SHR at birth, representing on average 53% of the values in WKY expressed as content per total cortex weight. Tissue total kallikrein did not differ between newborn SHR and WKY. 4. SHR at 4, 8 and 12 weeks of age had lower urinary active and total kallikrein excretion. Tissue active akllikrein, but not total kallikrein, was higher than in age-matched WKY per g of cortex weight or per mg of protein, whereas both tissue active and total kallikrein were lower in SHR when expressed as content per total cortex weight. At these three ages, active kallikrein represented, on average 86%, while total kallikrein represented 77%, of the values in age-matched WKY. 5. Our results indicate a defect in prokallikrein activation rather than in kallikrein synthesis in the renal cortex of SHR at birth. The reduction in urinary kallikrein excretion during the developmental phase of hypertension in young SHR is similar to the reduction observed in the renal tissue.
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PMID:Renal kallikrein activity in rats developing spontaneous hypertension. 292 23


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