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Biomedical subjects

A Soro

Publications and source records attributed to A Soro.

At least 73 records · Page 4Linked to original sources
PubMed1987

The effects of aprotinin, a kallikrein inhibitor, on renin release and urinary sodium excretion in mild essential hypertensives.

The effects of aprotinin on renin release and renal function were evaluated in 24 male essential hypertensive patients, on unrestricted (n = 17) and on chronic low as well as on high sodium intake. Aprotinin (1 X 10(6) kallikrein inhibitor units) or saline (200 ml) were infused in all patients for 6 h. Blood samples were taken for plasma renin activity (PRA) and 6-h urine collections were obtained for active and inactive kallikrein, sodium and potassium excretion measurement. In patients on unrestricted sodium diet, aprotinin had no effect on blood pressure (BP), glomerular filtration rate, renal plasma flow, urinary sodium and potassium excretion. However, an inverse relationship was found between pretreatment urinary sodium excretion and the per cent reduction of the latter after aprotinin. A significant reduction in urinary sodium excretion was induced by aprotinin in patients on high sodium intake, whereas no change was observed in the same patients when on a low sodium diet. Aprotinin reduced the urinary excretion of active kallikrein by 81% and the active to total kallikrein ratio from 24 to 6%. Infusion of aprotinin induced a significant decline in active renin but did not modify inactive renin levels in patients on unrestricted sodium diet as well as in patients on low or high sodium intake. Our data suggest that the inhibition of kallikrein and/or other serine proteases by aprotinin can interfere with renal release of active renin and also support the hypothesis that the renal kallikrein system exerts a regulatory control on sodium excretion in salt replete hypertensives.

Adult↗
PubMed1987

Role of renal kallikrein in modulating the antihypertensive effect of a single oral dose of captopril in normal- and low-renin essential hypertensives.

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.

Adult↗
PubMed1987

Natriuretic effect of acute nifedipine administration is not mediated by the renal kallikrein-kinin system.

Despite their vasodilating action, calcium antagonists increase renal sodium excretion. To ascertain whether renal kallikrein plays a role in the renal effects of calcium antagonists, nifedipine (N) (10 mg orally) or placebo (P) was given to 17 male patients with mild to moderate essential hypertension during a 6-h infusion of either saline (S) or aprotinin (A) (2 X 10(6) KIU in 200 ml of saline). Blood pressure (BP) and heart rate (HR) were measured every 10 min, and blood samples were taken at -10, 0, 30, 60, 120, 240, 360 min for plasma renin activity (PRA), creatinine, and osmolarity determinations. Urinary kallikrein, aldosterone, creatinine, and electrolytes were measured in 6-h urine collections. The acute administration of N induced a significant systolic BP (SBP) and diastolic (DBP) fall and a transient PRA increase that peaked at 30 min and were not modified by A infusion. Urinary volume (+47%), Na+ (+54%) and Cl- (+58%) excretion were significantly enhanced by N. There were less pronounced and statistically not significant increases in urinary excretion of Ca2+ (+38%) and K+ (+29%). Infusion of A did not interfere with the natriuretic effect of N. Our data do not support the hypothesis that the kallikrein-kinin system plays an important role in mediating the renal effects of nifedipine in humans.

Adult↗
PubMed1987

Relation between urinary kallikrein excretion and blood pressure response to a single oral dose of captopril.

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", 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.

Adult↗
PubMed1987

Angiotensin converting enzyme inhibition reduces ACTH release due to hypoglycaemia.

To investigate the role of Angiotensin II in the release of ACTH, the response of adrenocorticotrophic hormone to hypoglycaemia was studied before and during treatment with an angiotensin converting enzyme inhibitor, enalapril, in 15 male patients with essential hypertension. Plasma levels of ACTH were measured before and 60, 90 and 120 min after an i.v. bolus of normal saline, as placebo, and, 3 days later, after an i.v. bolus of regular insulin (0.15 U/Kg b.w.). Enalapril treatment was then started and both placebo and hypoglycaemic tests were repeated 15 days thereafter. No changes in ACTH plasma levels were observed after acute normal saline either before or during enalapril treatment. On the contrary, hypoglycaemia induced a sharp increase of ACTH before enalapril (from 19.5 +/- 4.1 to 74.4 +/- 13.0 pg/ml, p less than 0.01 60 min after insulin) but not during ACE inhibition (from 26.1 +/- 6.2 to 34.6 +/- 5.9 pg/ml, NS, at min 60 of the study). The present data confirm our previous observation on the reduction of the hypoglycaemic-induced ACTH release during ACE inhibition with captopril and support the hypothesis that circulating Ang II may exert a facilitating role on adrenocorticotrophic hormone release.

Adrenocorticotropic Hormone↗
PubMed1987

The effects of aprotinin, a glandular kallikrein inhibitor, on renin release and urinary sodium excretion in mild essential hypertensives.

The effects of aprotinin on renin release and renal function were evaluated in 24 male essential hypertensive patients, on unrestricted (N = 17) and on chronic low as well as on high Na intake. Aprotinin (1 x 10(6) KIU) or Saline (200 ml) were infused in all patients for 6 hrs. Blood samples were taken for plasma renin activity (PRA) and 6-hr urine collections were obtained for active and inactive kallikrein, Na+, K+, Cl-, Ca++ excretion measurements. In patients on unrestricted sodium diet aprotinin had no effect on BP, glomerular filtration rate, renal plasma flow, urinary sodium and potassium excretion. However an inverse relationship was found between pretreatment urinary sodium excretion and the percent reduction of the latter after aprotinin. A significant reduction in urinary sodium excretion was induced by aprotinin in patients on high sodium intake, whereas no change was observed in the same patients when on low sodium diet. Aprotinin reduced the urinary excretion of active kallikrein by 81% and the active to total kallikrein ratio from 24% to 6%, suggesting that it could interfere with the in-vivo activation of inactive kallikrein. Infusion of aprotinin induced a significant decline in active renin but did not modify inactive renin levels in patients on unrestricted sodium diet as well as in patients on low or high sodium intake. Our data suggest that the inhibition of kallikrein and/or other serine proteases by aprotinin can interfere with renal release of active renin and also support the hypothesis that the renal kallikrein system exerts a regulatory control on sodium excretion in salt replete hypertensives.

Adult↗
PubMed1983

[Multiple lentiginosis and hypertrophic obstructive cardiomyopathy].

Two patients with Multiple Lentiginosis (ML) had hypertrophic cardiomyopathy with severe obstruction of the right and left ventricular outflow tracts. ML is a rare syndrome in which there is a typical skin pigmentation disorder together with various other abnormalities like slight mental retardation, sensorineural deafness, genital and skeletal anomalies and sometimes a characteristic facies. Obstruction of the right ventricular outflow tract is frequent in such patients. The association of ML and obstructive hypertrophic cardiomyopathy has been recently reported. A critical examination of the literature in addition to our clinical observations suggests that the biventricular obstructive hypertrophic cardiomyopathy may play a major role in the clinical feature of ML syndrome.

Cardiomegaly↗
PubMed1980

[Long-term therapy with oral prazosin in chronic congestive heart failure: a clinical and echocardiographic evaluation (author's transl)].

Eight patients, ranging in age from 20 to 61 years (48 +/- 11 years, mean +/- 1 SD), with chronic heart failure due to idiopathic congestive cardiomyopathy (5 cases), ischemic heart disease with healed anterior myocardial infarction (2 cases), and rheumatic heart disease with a Björk-Shiley mitral valve prosthesis (1 case), received longterm therapy with oral prazosin in increasing doses (mean final dose: 26 +/- 6 mg/day). Administration of digoxin and diuretics were continued throught the study period (range: 21-228 days). All but one patient showed no functional improvement during the period of prazosin therapy (2 patients in New York Heart Association functional class IV, 5 patients in III class). One patient, the youngest of the group, who initially had class IV heart failure, showed improvement to III class after a 26 days administration of this vasodilator. Prazosin caused no consistent change in systemic arterial pressure, heart rate, cardio-thoracic ratio, and radiologic pulmonary venous stasis. Occasionally, on chest X-ray, a patient showed a transitory decrease of cardiomegaly and/or pulmonary venous congestion. P and QRS waves of ECG showed no evident change, as did serum creatinine and billirubin levels. On serial M-mode echocardiographic analyses, left ventricular minor axis dimension, ejection, and left atrial size showed no statistically significant change from pre-treatment averages of: 7.5 +/- 0.9 cm, 0.36 +/- 0.14, 4.9 +/- 1.3 cm, respectively. At late follow-up some indices of left ventricular performance showed a definite tendency to decrease: fractional shortening of the minor axis from 18.9 +/- 9.1 to 17.0 +/- 7.0, mean velocity of circumferential fiber shortening from 0.79 +/- 0.28 sec-1 to 0.69 +/- 0.28 sec-1, mean normalized systolic ejection velocity from 1.58 +/- 0.44 sec-1 to 1.47 +/- 0.39 sec-1, and mean normalized posterior wall velocity from 0.55 +/- 0.3 sec-1 to 0.49 +/- 0.18 sec-1. Prazosin in patients with chronic congestive failure due to cardiomyopathies, does not elict a persistent improvement of resting hemodynamics because of the development of pharmacodynamic tolerance in the majority of the patients. Prazosin, furthermore, does not improve the depressed myocardial contractility that necessarily affects the long-term prognosis of these patients.

Adult↗