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N Glorioso

Publications and source records attributed to N Glorioso.

At least 19 recordsLinked to original sources
PubMed2006

Use of antihypertensive and lipid-lowering drugs: the management of cardiovascular risk in clinical practice.

The objective of the study was to analyse the treatment of high blood pressure (BP) and hypercholesterolaemia, as well as the effect of individual or combined antihypertensive-hypocholesterolaemic therapy on BP control and on circulating cholesterol. A retrospective study was performed using clinical data recorded in the general practitioner's database. The sample included all patients, aged > or =18 years, with BP reading or low-density lipoprotein (LDL) cholesterol measurement recorded between January 2003 and December 2004. BP and LDL cholesterol targets were defined using cutoffs based on the guidelines of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC7) and the National Cholesterol Education Program (NCEP/ATPIII). The study included 4764 patients (mean age 67.6+/-11.8 years, 43.5% males). Target BP was achieved in a higher number of patients under combined antihypertensive-hypocholesterolaemic therapy than in those treated only with antihypertensives: 57.0 vs 50.0% in patients with history of cardio/cerebrovascular (CV) hospitalization, 27.0 vs 16.9% in patients with diabetes or chronic renal insufficiency (CRI) and 59.7 vs 49.1% in patients with no CV hospitalization nor diabetes and nor CRI. The LDL cholesterol target was achieved in 61.3% of the subjects: it was independent on the therapy (individual or combined), but related to the degree of cardiovascular risk. Analysing the data contained in the general medicine database made it possible to evaluate the treatment of high BP and hypercholesterolaemia in relation to cardiovascular risk in clinical practice and to establish the need to pay greater attention to achieving the objective set by guidelines.

Aged↗
PubMed2006

Pharmacogenomics of essential hypertension: are we going the right way?

Identifying the genetic predictors of the therapeutic response to drugs is the role of pharmacogenomics. Although polymorphisms in several genes have been associated with the blood pressure response to diuretics, beta-blockers and ACE-inhibitors, the pharmacogenomics of essential hypertension is still attempting to find satisfactory scientific evidence to be translated into clinical practice. The main reasons for this apparent failure are: the small sample sizes of the cohorts of patients analyzed, the methodological variability, the complexity of the biological organization, the context-dependency and the genetic heterogeneity. This review will summarize the available data on antihypertensive drugs and the criteria used for study design and conduction, focusing on their strong points and limitations.

Antihypertensive Agents↗
PubMed2001

Urinary adrenomedullin is related to ET-1 and salt intake in patients with mild essential hypertension. Salt Sensitivity Group of Italian Society of Hypertension.

Adrenomedullin (ADM) infusion increases salt excretion in the rat. However, there is no evidence that this substance is related to changes in salt intake in humans. In this study we sought whether the urinary excretion rate of this autacoid is related to salt intake and by the expected changes in arterial pressure in patients with mild essential hypertension. The influence of salt intake on the renal excretion of ADM was investigated in 55 hypertensive patients in a double blind, randomized and crossover study comparing a 2-week 50 mmol/day salt intake period with a 150 mmol/day salt intake period. Twenty-four-hour ADM and endothelin-1 (ET-1) excretion rate were measured by radioimmunoassay on preextracted urinary samples (intraassay confidence variable <8%). The antibodies used in these assays had minimal ADM-ET-1 cross-reactivity (<1%). Twenty-four-hour microalbuminuria was measured by nephelometry. On univariate analysis changes in urinary ADM were significantly related to those in salt excretion (r = 0.33, P = .01) as well as to changes in urinary ET-1 (r = 0.56, P = .0001). Furthermore, changes in urinary albumin excretion were related to those in urinary ET-1 (r = 0.26, P = .05), but were independent of those in urinary ADM (P = .19). In a multiple regression model including age, sex, body mass index, and changes in systolic pressure, plasma renin activity and plasma aldosterone and urine volume, salt excretion resulted as the stronger independent predictor of urinary ADM (r = 0.33, P = .01). However, changes in urinary salt lost prediction power (P = .11) for urinary ADM when urinary ET-1 was introduced into the model. In this model (multiple r = 0.31) urinary ET-1 resulted to be the only independent predictor of urinary ADM (beta = 0.56, P = .0001). This study is the first to show that the renal excretion of ADM is related to changes in salt intake and that it is tightly linked to that of ET-1. The data support the notion that these autacoids play a role in the regulation of sodium metabolism in patients with mild hypertension. The intercorrelations between ET-1, ADM, and microalbuminuria are compatible with the hypothesis that ET-1 is involved in a salt-induced increase in glomerular pressure and suggest that ADM may act as a counterregulatory factor in this situation.

Adrenomedullin↗
PubMed2001

Non-association of the thiazide-sensitive Na,Cl-cotransporter gene with polygenic hypertension in both rats and humans.

OBJECTIVE: Genes underlying renal regulation of sodium and water balances are a priori valid candidates for polygenic hypertension susceptibility genes. Having recently identified the association of alpha1 Na,K-ATPase (ATP1A1) and Na,K,2Cl-cotransporter (NKCC2) as interacting hypertension susceptibility loci in both a rat model and human hypertensives, we investigated whether the thiazide-sensitive Na,Cl-cotransporter (TSC) gene contributes to hypertension susceptibility in a rat F2 intercross and in a northern Sardinian human cohort for polygenic hypertension. SUBJECTS AND METHODS: The rat TSC (rTSC) gene was analyzed directly for cosegregation with salt-sensitive hypertension in an F2 (Dahl S x Dahl R) rat population (n = 102) characterized for blood pressure by radiotelemetry. The human TSC (hTSC) gene was analyzed for association with hypertension in a human hypertensive cohort from northern Sardinia that consisted of 220 unrelated normotensives and 254 unrelated hypertensives. The TSC gene was subjected to single locus and digenic (in combination with ATP1A1 and NKCC2 genes) analyses in both rat and human cohorts. RESULTS: In both rat model and human cohorts, the rTSC and hTSC genes did not show linkage or association with high blood pressure, respectively. Furthermore, interaction with either ATP1A1 or NKCC2 was not detected in both the rat F2 intercross and human hypertension cohorts. CONCLUSIONS: These data exclude a primary role of the TSC gene in hypertension pathogenesis in the hypertension cohorts studied.

Alleles↗
PubMed2001

Interaction of alpha(1)-Na,K-ATPase and Na,K,2Cl-cotransporter genes in human essential hypertension.

Essential hypertension is a common disease the genetic determinants of which have been difficult to unravel because of its clinical heterogeneity and complex, multifactorial, polygenic etiology. Based on our observations that alpha(1)-Na,K-ATPase (ATP1A1) and renal-specific, bumetanide-sensitive Na,K,2Cl-cotransporter (NKCC2) genes interactively increase susceptibility to hypertension in the Dahl salt-sensitive hypertensive (Dahl S) rat model, we investigated whether parallel molecular genetic mechanisms might exist in human essential hypertension in a relatively genetic homogeneous cohort in northern Sardinia. Putative ATP1A1-NKCC2 gene interaction was tested by comparing hypertensive patients (blood pressure [BP] >165/95 mm Hg) with normotensive controls age >60 years with BP <140/85 mm Hg. Genotype analysis with microsatellite markers revealed conformation to Hardy-Weinberg proportions for 6 alleles of both ATP1A1 (D1S453) and NKCC2 (NKCGT7) markers, respectively. Two-by-six chi(2) analysis of alleles identified overrepresentation of ATP1A1 No. 4 and NKCC2 No. 4 alleles, respectively, in hypertensives compared with controls. With a qualitative trait framework, single-gene analysis detected association of both the ATP1A1 No. 4 allele (P=0.004, chi(2)=8.094, df=1) and the NKCC2 No. 4 allele (P=0.0002, chi(2)=14.279, df=1) with moderate to severe hypertension. Digenic analysis revealed that ATP1A1 No. 4-NKCC2 No. 4 allele interaction increases susceptibility to hypertension (P<0.0001, chi(2)=22.3, df=1) beyond levels obtained in single-gene analysis. Analysis was also performed in a quantitative trait framework with BP as the continuous trait parameter. Digenic analysis of ATP1A1 No. 4-NKCC2 No. 4 allele interaction revealed significant association with systolic (1-way ANOVA, P=0.000076) and diastolic (P=0.00099) BP. Interaction was corroborated by 2x2 factorial ANOVA for interaction (systolic BP interaction term, P<0.05, diastolic BP interaction term, P=0.035). The data are compelling that ATP1A1 and NKCC2 genes are candidate interacting hypertension-susceptibility loci in human essential hypertension and affirm gene interaction as an important genetic mechanism underlying hypertension susceptibility. Although corroboration in other cohorts and identification of functionally significant mutations are imperative next steps, the data provide a genotype-stratification scheme, with 4-fold predictive value (odds ratio, 4.28; 95% confidence interval, 2.29 to 8.0), which could help decipher the complex genetics of essential hypertension.

Adult↗
PubMed2001

Absence of D147E mutation of CYP11B2 gene in hypertensive patients with increased corticosterone and aldosterone production.

OBJECTIVE: 11beta-Hydroxylase and aldosterone synthase are two highly homologous genes involved in different forms of human hypertension and in different animal models of hypertension. It has been shown that the conservative substitution D147E in the human CYP11B2 gene results in an increased production of corticosterone and aldosterone in vitro. A gene conversion between the CYP11B1 and CYP11B2 genes could be responsible for such a substitution. METHODS: In this study we investigated the presence of the mutation D147E of CYP11B2 in a group of 128 patients with primary aldosteronism, 68 patients with essential hypertension and increased corticosterone production and in 48 normal volunteers. RESULTS AND CONCLUSIONS: We did not identify any patient carrying this mutation, indicating that if it exists it is very rare and so has no relevance in determining the increased steroid excretion seen in some subtypes of human hypertension.

Aged↗
PubMed1999

High plasma prorenin in non diabetic siblings of non insulin-dependent diabetes mellitus patients.

In a large cohort (no. = 361) of NIDDM probands and their concordant/discordant siblings from no. = 132 families we studied: 1. the levels of plasma prorenin in non affected siblings of NIDDM probands as opposed to normal subjects without family history of diabetes, and 2. whether plasma prorenin raises in parallel to urinary protein loss in NIDDM patients. Prorenin (solid-phase trypsin) and micro-macroalbuminuria (radioimmunoassay) were evaluated. Plasma prorenin was higher in NIDDM probands and siblings than in non NIDDM siblings (37+/-31 vs. 25+/-15 ng/ml/h, p<0.0005) who, in turn, showed higher plasma prorenin than non diabetic controls without family history of diabetes (25+/-15 vs. 17+/-8 ng/ml/h, p<0.005). Plasma prorenin was higher in NIDDM siblings of micro-macroalbuminuric probands than in NIDDM siblings of non micro-macroalbuminuric probands (40+/-26 vs. 29+/-20 ng/ml/h, mean +/- SD, p = 0.0058) whereas no difference was found among non diabetic siblings (24+/-14 vs. 22+/-11 ng/ml/h, NS). Our data confirm that plasma prorenin is elevated in NIDDM patients, and show: 1. that the raise of plasma prorenin in non-NIDDM siblings of a diabetic patient does not depend entirely from the presence of diabetes, and 2. that plasma prorenin in NIDDM probands and their concordant siblings goes along with micro-macroalbuminuria.

Blood Pressure↗
PubMed1999

Controlled study of the effect of angiotensin converting enzyme inhibition versus calcium-entry blockade on insulin sensitivity in overweight hypertensive patients: Trandolapril Italian Study (TRIS).

OBJECTIVE: The aim of this study was to evaluate the effect of trandolapril, an angiotensin converting enzyme inhibitor, on blood pressure, forearm blood flow and insulin sensitivity in comparison with nifedipine gastrointestinal therapeutic system. PATIENTS AND METHODS: This is a multicentre, two-way parallel-group, open-label comparative study in 90 overweight hypertensive patients, who were randomly assigned to treatment for 8 weeks with either trandolapril or nifedipine. At baseline and after treatment, all patients underwent an oral glucose tolerance test, an evaluation of their metabolic profiles and a euglycaemic hyperinsulinaemic clamp test. In a subgroup of 18 patients, a forearm study was carried out. RESULTS: Blood pressure fell by the second week of treatment and remained significantly reduced compared with baseline in both treatment groups. Plasma triglyceride levels were also significantly reduced after trandolapril therapy, but no significant changes occurred in the other metabolic parameters during treatment with either drug. During the euglycaemic hyperinsulinaemic clamp, whole-body glucose use was similar in the two treatment groups at baseline, and a moderate but statistically significant increase in insulin sensitivity was observed after trandolapril treatment (trandolapril: 5.0 +/- 0.2 versus 4.5 +/- 0.2 mg/kg per min; nifedipine: 4.1 +/- 0.3 versus 4.2 +/- 0.3 mg/kg per min; P < 0.05, versus baseline and trandolapril versus nifedipine treatment). Skeletal muscle glucose uptake was significantly higher after trandolapril than after nifedipine therapy (5.0 +/- 0.7 and 3.0 +/- 0.4 mg/min, respectively; P < 0.01). As forearm blood flow was similar in the two treatment groups at baseline and was unchanged after 8 weeks of therapy, skeletal muscle glucose extraction was significantly greater in the ACE inhibitor treated-group than in the nifedipine comparative group (trandolapril: baseline 21 +/- 2, treatment 24 +/- 3 mg/dl; nifedipine: baseline 18 +/- 3, treatment 16 +/- 2 mg/dl; P < 0.05, trandolapril versus nifedipine treatment). CONCLUSIONS: During short-term treatment, ACE inhibition with trandolapril was able to moderately improve insulin sensitivity, in comparison with calcium blockade, and this effect appeared to be independent of the haemodynamic action of the drug.

Adult↗
PubMed1999

The role of alpha-adducin polymorphism in blood pressure and sodium handling regulation may not be excluded by a negative association study.

The basic requirement for declaring an association study positive is that the "hypertension-favoring" allele is more frequent in hypertensive cases than in normotensive controls. However, both positive and negative associations with hypertension have been found for the same polymorphism when studied in different populations. In the present study, we addressed the question of the possible cause(s) of this discrepancy among populations by using the alpha-adducin polymorphism as a paradigm. Four hundred ninety hypertensives and 176 normotensives enrolled in Sassari, Italy, and 468 hypertensives and 181 normotensives enrolled in Milano, Italy, were genotyped for the alpha-adducin Gly460Trp polymorphism. The blood pressure response to 2 months of hydrochlorothiazide therapy could be evaluated in 143 (85 in Sassari and 58 in Milano) hypertensives with and without the 460Trp alpha-adducin allele. The alpha-adducin 460Trp allele was not significantly more frequent in hypertensives in the Sassari population but was more frequent in hypertensives than in normotensives in Milano (P=0.019). Basal plasma renin activity was lower and blood pressure fall after diuretic therapy more pronounced (P<0.01) in hypertensives carrying at least one 460Trp allele than in Gly460Gly homozygotes, irrespective of their membership in the Sassari or Milano cohort. The effect of alpha-adducin genotype in predicting basal plasma renin activity and blood pressure decrease with diuretic treatment is similar in Sassari and Milano, despite the lack of association of the alpha-adducin genotype with hypertension in Sassari.

Aged↗
PubMed1999

Effect of the HMG-CoA reductase inhibitors on blood pressure in patients with essential hypertension and primary hypercholesterolemia.

Certain hydroxymethylglutaryl coenzyme A reductase inhibitors, ie, statins, may cause vasodilation by restoring the endothelial dysfunction that frequently accompanies hypertension and hypercholesterolemia. Several studies have found that a blood pressure reduction is associated with the use of statins, but conclusive evidence from controlled trials is lacking. After an 8-week placebo and diet run-in period, 30 persons with moderate hypercholesterolemia and untreated hypertension (total cholesterol 6.29+/-0.52 mmol/L, systolic and diastolic blood pressure 149+/-6 and 97+/-2 mm Hg) were randomized in a double-blind manner to placebo or pravastatin (20 to 40 mg/d) in a crossover design. In 25 participants who completed the 32-week trial, pravastatin decreased total and LDL cholesterol (both -1.09 mmol/L, P=0.001), systolic and diastolic blood pressure (-8 and -5 mm Hg, both P=0.001), and pulse pressure (-3 mm Hg, P=0.011) and blunted the blood pressure increase caused by the cold pressor test (-4 mm Hg, P=0.005) compared with placebo. It also reduced the level of circulating endothelin-1 (P=0.001). The blood pressure results were virtually unchanged in stratified analyses according to gender and age and in intention-to-treat analyses that included the 5 patients who dropped out of the study. When the participants were taking either placebo or pravastatin, blood pressure was not significantly correlated with total or LDL cholesterol or with circulating endothelin-1. Pravastatin decreases systolic, diastolic, and pulse pressures in persons with moderate hypercholesterolemia and hypertension. This antihypertensive effect may contribute to the documented health benefits of certain statins.

Adult↗
PubMed1997

Cardiovascular phenotype of a mouse strain with disruption of bradykinin B2-receptor gene.

BACKGROUND: To evaluate the role of kinins in the regulation of cardiovascular function, we studied the phenotype of a mouse strain with disruption of the bradykinin B2-receptor gene (Bk 2r-/-). METHODS AND RESULTS: Under basal conditions, tail-cuff blood pressure was higher in Bk2r-/- than in wild-type Bk2r+/+ and heterozygous Bk2r+/- mice (124+/-1 versus 109+/-1 and 111+/-2 mm Hg, respectively; P<.01 for both comparisons), a difference that was confirmed by measurements of intra-arterial blood pressure in unanesthetized mice. Heart weight was greater in Bk2r-/- than in Bk2r+/+ and Bk2r+/- mice (505+/-10 versus 449+/-12 and 477+/-10 mg/100 g body wt, P<.05). Chronic blockade of B2-receptors by Icatibant (50 nmol/100 g body wt twice a day S.C.) or inhibition of nitric oxide synthase by nitro-L-arginine-methyl ester (0.14 mmol/100 g body wt orally) increased the blood pressure of Bk2r+/+ to the levels of Bk2r-/- mice. Compared with the wild-type strain, both Bk2r-/- and Bk2r+/- mice showed exaggerated vasopressor responses to angiotensin II. In addition, chronic administration of an angiotensin AT1-receptor antagonist reduced the basal blood pressure of Bk2r-/- by 21+/-3 mmHg (P<.05) to the levels of Bk2r+/+. No difference was detected between strains as far as plasma renin activity and the expression of renin and AT1-receptor genes are concerned. Chronic salt loading (0.84 mmol/g chow for 15 days) increased the blood pressure of Bk2r-/- and Bk2r+/- by 34+/-3 and 14+/-6 mm Hg, respectively, whereas it was ineffective in Bk2r+/+. CONCLUSIONS: Our results suggest that a normally functioning B2-receptor is essential for the maintenance of cardiovascular homeostasis in mice. Dysfunction of the kallikrein-kinin system could contribute to increase blood pressure levels by leaving the activity of vasoconstrictor agents unbalanced.

Angiotensin II↗
PubMed1997

Polymorphisms of alpha-adducin and salt sensitivity in patients with essential hypertension.

BACKGROUND: Abnormalities in renal sodium transport may be involved in hypertension. Adducin, an alpha/beta heterodimeric protein found in the renal tubule is thought to regulate ion transport through changes in the actin cytoskeleton. We investigated whether an alpha-adducin polymorphism (Gly 460 Trp) is involved in essential hypertension in two separate populations. METHODS: Linkage analysis of three DNA markers at different distances from the alpha-adducin locus (20-2500 kb) was done in 137 hypertensive sibling-pairs. 477 hypertensive and 322 normotensive individuals were genotyped for the alpha-adducin polymorphism. The blood-pressure response to acute and chronic changes in sodium balance was studied in hypertensive individuals with and without the 460 Trp alpha-adducin allele. FINDINGS: Significant linkage was found for all three markers in the sibling-pair study. The extra shared alleles (9.1%, 6.5%, and 4.7%) and the significance level for linkage (p = 0.0006, p = 0.0119, and p = 0.0211) both decreased with increasing distance from the alpha-adducin locus. There was a significant association between the 460 Trp mutation and hypertension (p = 0.0003). In the salt-sensitivity test, to assess the acute blood-pressure response to changes in body sodium in 86 hypertensive patients, the decrease in mean arterial pressure was greater in 65 patients who were heterozygous for the mutant allele (Gly/Trp) than in 21 wild-type homozygotes (Gly/Gly) (mean decrease 15.9 [SE 2.0] vs 7.4 [1.3] mm Hg; p = 0.001). Similarly, 21 heterozygous hypertensive patients showed a greater fall in mean arterial pressure in response to 2 months' treatment with hydrochlorothiazide than did 37 wild-type homozygous hypertensive patients (mean decrease 14.7 [2.2] vs 6.8 [1.4] mm Hg; p = 0.002). INTERPRETATION: Our findings of significant linkage of the alpha-adducin locus to essential hypertension and greater sensitivity to changes in sodium balance among patients with the mutant allele suggest that alpha-adducin is associated with a salt-sensitive form of essential hypertension. We suggest the alpha-adducin polymorphism may identify hypertensive patients who will benefit from diuretic treatment or manoeuvres to reduce total body sodium.

Aged↗
PubMed1997

Regulation of bradykinin B2-receptor expression by oestrogen.

1. Tissue kallikrein is overexpressed in the kidney of female rats, this sexual dimorphism being associated with a greater effect of early blockade of bradykinin B2-receptors on female blood pressure phenotype. We evaluated the effect of ovariectomy and oestradiol benzoate (50 micrograms kg-1 every two days for two weeks) on the vasodepressor response to intra-arterial injection of bradykinin (150-900 ng kg-1) and on the expression of bradykinin B2-receptors. 2. Ovariectomy reduced the magnitude of the vasodepressor response to bradykinin and unmasked a secondary vasopressor effect. Oestrogen replacement restored the vasodepressor response to bradykinin in ovariectomized rats. 3. The vasodepressor responses to sodium nitroprusside (3-18 micrograms kg-1), acetylcholine (30-600 ng kg-1), desArg9-bradykinin (150-900 ng kg-1) or prostaglandin E2 (30-600 ng kg-1) were significantly reduced by ovariectomy. Oestrogen restored to normal the responses to desArg9-bradykinin, acetylcholine and prostaglandin E2, but not that to sodium nitroprusside. 4. B2-receptor mRNA levels were decreased by ovariectomy in the aorta and kidney and they were restored to normal levels by oestrogen. Neither ovariectomy nor oestradiol affected receptor expression in the heart and uterus. 5. These results indicate that oestrogen regulates B2-receptor gene expression and function. Since kinins exert a cardiovascular protective action, reduction in their vasodilator activity after menopause might contribute to the increased risk of pathological cardiovascular events. Conversely, the cardioprotective effects of oestrogen replacement might be, at least in part, mediated by activation of the kallikrein-kinin system.

Animals↗
PubMed1997

Kallikrein-kinin system and blood pressure sensitivity to salt.

We evaluated the blood pressure response to chronic salt loading in a rat strain inbred for low urinary kallikrein excretion. Low-kallikrein rats showed greater systolic blood pressure values (130 +/- 1 versus 114 +/- 2 mm Hg in controls; P < .05) at 9 weeks of age. Systolic blood pressure was increased after 10 days of dietary sodium loading in the low-kallikrein group and remained unchanged in controls (153 +/- 1 versus 112 +/- 2 mm Hg, P < .01). In additional experiments, blood pressure sensitivity to salt was tested in low-kallikrein rats receiving a chronic infusion of rat glandular kallikrein (1.7 micrograms/day per 100 g body weight, IV) or vehicle. Systolic blood pressure of vehicle-treated rats was increased by salt loading (from 138 +/- 1 to 158 +/- 2, 153 +/- 1, and 145 +/- 2 mm Hg at 5, 10, and 15 days, respectively; P < .01), while it remained unchanged in the kallikrein-treated group (from 136 +/- 2 to 146 +/- 5, 140 +/- 2, and 134 +/- 4 mm Hg at 5, 10, and 15 days, respectively; P = NS). Urinary kallikrein excretion was increased by kallikrein infusion (from 13.6 +/- 1.4 to 17.8 +/- 2.1 nanokatals per 24 hours; P < .01). Plasma immunoreactive kallikrein levels were higher in the kallikrein-treated group (66.4 +/- 4.4 versus 57.7 +/- 1.4 ng/mL in vehicle-treated rats; P < .05). On normal sodium diet, the ratio of kidney weight to body weight was lower in low-kallikrein rats (329 +/- 5 versus 370 +/- 8 mg/100 g body weight in controls; P < .01). This difference was associated with a decreased number of glomeruli per unit square area and increased width of Bowman's space. These results indicate that kallikrein replacement prevents the exaggerated blood pressure increase observed in rats with a genetically determined defect in urinary kallikrein excretion. Histological abnormalities are present at different levels in the nephron, and they may be functionally related to the altered cardiovascular and renal phenotype of this strain.

Animals↗
PubMed1996

Blood pressure sensitivity to salt in rats with low urinary kallikrein excretion.

We evaluated if a rat strain inbred for reduced urinary kallikrein excretion differs from normal-kallikrein Wistar rats regarding blood pressure in basal conditions and during alterations in sodium balance. Low-kallikrein rats showed greater systolic blood pressure values (125 +/- 3 vs. 114 +/- 2 mmHg in controls, P < 0.01) at 9 weeks of age. Systolic blood pressure was increased after 20 days of dietary sodium loading in the low-kallikrein group and remained unchanged in controls (150 +/- 6 vs. 112 +/- 2 mmHg, P < 0.01) and this effect was associated with a reduced cumulative excretion of sodium (23% less in the low-kallikrein group compared with controls, P < 0.01). Urinary creatinine excretion was decreased by sodium loading in both groups, and this effect was more pronounced in the low-kallikrein group. The group-difference in urinary kallikrein excretion found in basal conditions (2.49 +/- 0.10 vs. 7.78 +/- 0.53 Pkat/100 g body weight, P < 0.01) was enhanced by high salt diet (1.05 +/- 0.21 vs. 8.31 +/- 0.70 Pkat/100 g body weight, P < 0.01). The ratio of heart weight to body weight was significantly greater in low-kallikrein rats (331 +/- 7 vs. 275 +/- 4 mg/100 g body weight, P < 0.01), whereas the ratio of kidney weight to body weight was lower (329 +/- 5 vs. 370 +/- 8 mg/100 body weight, P < 0.01). Our results indicate that a genetically-determined defect in urinary kallikrein excretion is associated with a greater blood pressure sensitivity to salt, possibly due to altered renal sodium handling.

Animals↗
PubMed1996

Urinary kallikrein: a marker of blood pressure sensitivity to salt.

We evaluated if a rat strain inbred for low urinary kallikrein excretion differs from normal-kallikrein Wistar rats regarding blood pressure levels in basal conditions and during alterations in sodium balance. Blood pressure was measured in unanesthetized rats on normal sodium intake. Then, blood pressure sensitivity to salt was evaluated over a period of 20 days of high sodium diet (0.84 mmol per g chow). Low-kallikrein rats showed greater systolic blood pressure levels (125 +/- 3 vs. 114 +/- 2 mm Hg in controls, P < 0.01) at nine weeks of age. Systolic blood pressure was increased after sodium loading in the low-kallikrein group and remained unchanged in controls (150 +/- 6 vs. 112 +/- 2 mm Hg, P < 0.01). This effect was associated with a reduced cumulative urinary excretion of sodium in the low-kallikrein rats. No group difference was found in the clearance of endogenous creatinine in basal conditions. Urinary creatinine excretion decreased during sodium loading, particularly in the low-kallikrein group. The group-difference in urinary kallikrein excretion found in basal conditions (6.85 +/- 0.31 vs. 20.74 +/- 1.71 nkat/24 hr in controls, P < 0.01) was enhanced by high salt diet (2.96 +/- 0.67 vs. 22.07 +/- 2.47 nkat/24 hr in controls, P < 0.01). In addition, renal kallikrein activity and content were reduced in low-kallikrein rats. The latter group showed a greater ratio of heart weight to body wt both in basal conditions and after sodium loading. The ratio of kidney weight to body wt was reduced after sodium loading. These results indicate that a genetically-determined defect in urinary kallikrein excretion is associated with a greater blood pressure sensitivity to salt, possibly due to altered renal sodium handling.

Animals↗