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Biomedical subjects

M Castellano

Publications and source records attributed to M Castellano.

At least 145 records · Page 8Linked to original sources
PubMed1986

Adrenergic activity and left ventricular function during treatment of essential hypertension with calcium antagonists.

The effects of 2 calcium antagonist drugs, verapamil and nifedipine, on blood pressure, heart rate (HR), plasma catecholamines, plasma renin activity and some echocardiographic indexes of left ventricular anatomy and function were studied in 67 patients with essential hypertension. The short- and long-term antihypertensive effect of verapamil was not associated with significant changes in HR, plasma catecholamines or plasma renin activity; the decrease in blood pressure after nifedipine was associated with a significant increase in HR and plasma catecholamines (mainly noradrenaline) (p less than or equal to 0.05). These findings were confirmed in a crossover comparison in 12 hospitalized patients treated with verapamil and nifedipine for 8 days each. The dose of isoproterenol that increased HR by 25 beats/min was significantly increased during verapamil treatment (p less than 0.05) and decreased during nifedipine treatment (p less than 0.01). Stroke volume and shortening fraction increased slightly but significantly (p less than 0.05) with 3 months of nifedipine treatment, while no change was detected with verapamil treatment. Left ventricular mass was significantly decreased after effective antihypertensive treatment for 3 months with verapamil or nifedipine (p less than or equal to 0.05).

Adult↗
PubMed1986

Similarities and differences in the antihypertensive effect of two calcium antagonist drugs, verapamil and nifedipine.

The short- and long-term effects of two calcium channel blocking drugs, verapamil and nifedipine, on blood pressure, heart rate, plasma catecholamines, plasma renin activity, plasma volume and cardiac performance (echocardiography) were studied in essential hypertensive patients and in normal subjects. Verapamil, 160 mg orally, reduced blood pressure within 60 minutes in 22 hypertensive patients, but not in 12 normotensive subjects. Nifedipine, 10 mg sublingually, reduced blood pressure within 15 minutes in 19 hypertensive patients, but not in 7 normotensive subjects. Plasma noradrenaline was significantly increased both in normal subjects and in hypertensive patients only after nifedipine was administered. Verapamil (80 mg three times a day) first, and nifedipine (10 mg three times a day) thereafter, or vice versa, were given to 12 hospitalized hypertensive patients on a fixed sodium and potassium intake; the drugs produced similar blood pressure reductions, but heart rate and plasma catecholamines were increased only after nifedipine (p less than 0.05). Neither drug affected plasma volume, aldosterone or plasma renin activity. Long-term ambulatory treatment with verapamil (80 or 160 mg three times a day for 2 to 4 months) or nifedipine (10 mg three times a day for 2 months) produced changes in all variables that were similar to those observed in the hospital (controlled) study. Shortening fraction was significantly increased after nifedipine (p less than 0.05) but no change was observed after verapamil. In conclusion, blood pressure is effectively reduced by both verapamil and nifedipine; an appreciable adrenergic stimulation may be caused by nifedipine, but usually not by verapamil, and fluid retention, renin release or myocardial depression is not observed during verapamil or nifedipine treatment.

Adult↗
PubMed1986

Renal noradrenergic and dopaminergic activity in patients with borderline essential hypertension.

An opposite modulatory influence of renal noradrenergic and dopaminergic activities on sodium excretion has been suggested. In this study urinary noradrenaline (UNA) and dopamine (UDA) excretion were evaluated in patients with borderline essential hypertension (BH; n = 9) and in patients with established essential hypertension (EH; n = 11) as well as in normal subjects (NT, n = 8), during normal sodium and potassium intake. Measurements were performed on fractionated urine collections on two separate days: on the first day under basal conditions and on the second day after saline infusion (SAL), 2L/2h, i.v. In BH, basal UNA and UDA were higher with respect to NT and EH. The difference was significant (p less than 0.05) in urine collected between 8 and 14 h. In all three groups, SAL induced a significant decrease in UNA and a significant increase in UDA; the decrease in UNA after SAL was significantly lower in EH in respect to BH and NT. In conclusion, the increased UDA in BH may represent a compensatory mechanism to a defect in sodium excretion, possibly due to elevated renal and/or systemic noradrenergic activity; the normal response to volume and salt loading suggests that the physiological modulation of sympathetic tone is still preserved in BH.

Adult↗
PubMed1986

Intoxication of 76 children by chlorine gas.

A collective intoxication with chlorine gas in 76 children (21 males, 55 females; the median age was 9.9 years) is reported. They were treated with a combination of oxygen gas (O2) and corticosteroids until the symptoms disappeared.

Accidents↗
PubMed1984

Plasma catecholamines assay: comparison between fluorimetric and radioenzymatic methods.

Plasma catecholamines were simultaneously measured in duplicate plasma samples by the fluorimetric method of Renzini et al. (1970) Clin. Chim. Acta 39, 587-594) and by the radioenzymatic method of Da Prada & Zurcher ((1976) Life Sci. 19, 1161-1174). The correlation of noradrenaline and adrenaline plasma concentrations determined by the two methods were, respectively, r = 0.95 (p less than 0.001) and r = 0.75 (p less than 0.01). The fluorimetric method was less sensitive, but more economical and less time-consuming than the radioenzymatic method. The fluorimetric method is still of value for measuring plasma catecholamines in man.

Catecholamines↗
PubMed1984

Supine and standing plasma catecholamines in essential hypertensive patients with different renin levels.

In this study we measured plasma renin activity (PRA), plasma norepinephrine (NE) and epinephrine (E), heart rate (HR) and blood pressure (BP) in 89 supine (sup) essential hypertensive patients (pts), WHO I-II, after 3-5 days of fixed normal sodium and potassium intake; the same measurements were repeated after 30' of active standing (stand) in 44/89 pts. In the whole population NE was directly related to PRA, both in sup and in stand position (p less than 0.01). NE was above the upper limits of normotensive controls in 2/34 (6%) pts with low PRA, in 6/40 (17%) pts with normal PRA and in 6/15 (40%) pts with high PRA. In respect to normal PRA pts, HR was significantly lower in low PRA pts and higher in high PRA pts, both in sup and in stand position (p less than 0.05). Sup and stand NE and E were similar in low and normal PRA pts, while they were significantly higher in high PRA pts (p less than 0.05). These results suggest an increased adrenergic tone at least in some high PRA pts, and blunted responsiveness of renal and cardiac beta adrenergic receptors to adrenergic stimuli in low PRA pts.

Adult↗
PubMed1983

Relationships between plasma catecholamines, renin, age and blood pressure in essential hypertension.

The aim of this study was to examine the interrelationships between age, plasma catecholamines, plasma renin activity (PRA) and blood pressure in essential hypertensive (EH) patients. PRA, plasma noradrenaline (NA) and adrenaline (A) were measured in 76 consecutive EH patients (WHO stages 1-2, aged 24-66 years) and in 28 normotensive subjects (aged 25-64 years) studied at rest in supine position after 5 days of normal fixed sodium and potassium intake. Both plasma NA and A were slightly but significantly higher in EH patients (p less than 0.05). While no relationship was found between the various parameters in normotensive subjects, in EH patients, particularly those at WHO stage 2, plasma NA was directly related to mean blood pressure (MBP) (p less than 0.001) and PRA (p less than 0.01). Plasma A was weakly related to MBP (p less than 0.05); PRA was inversely related to age (p less than 0.01) but no relationship was found between NA or A and age. Partial correlation analysis confirmed all these relationships. In fact, NA was related to MBP also considering constant PRA (p less than 0.001) or age (p less than 0.001), and NA was related to PRA also considering constant MBP (p less than 0.01) or age (p less than 0.001). Acute pharmacological alpha- and beta-blockade, with labetalol 100 mg i.v., induced a reduction of MBP which was directly related to basal plasma NA (p less than 0.001). These results support the view that in EH the sympathetic nervous system might be in part responsible for PRA levels and for the severity of hypertension.

Adult↗
PubMed1982

Angiotensin-converting enzyme inhibition, catecholamines and hemodynamics in essential hypertension.

Captopril was given to 15 unselected patients with essential hypertension (WHO II) at a dose range of 300 to 600 mg/day. Hemodynamic indexes (thermodilution) as well as levels of plasma norepinephrine, epinephrine, renin activity and aldosterone were determined simultaneously at the end of 2 weeks of placebo and after 8 weeks of captopril treatment. Systolic and diastolic arterial pressures were reduced significantly by treatment both supine (p less than 0.0025) and standing (p less than 0.0025). The diastolic arterial pressure was normalized (less than 95 mm Hg) in five patients and significantly reduced in four, whereas six patients were considered poor responders (mean arterial pressure decrease 10 mm Hg or less). The decrease in arterial pressure correlated significantly with the reduction in total peripheral resistance (r = 0.71), whereas cardiac index did not change and stroke index increased because of a slight decrease of heart rate. Plasma and urinary norepinephrine and epinephrine did not change during treatment. Moreover, the response of both heart rate and plasma catecholamines to upright posture was not altered by captopril treatment. Plasma renin activity increased and plasma aldosterone concentration decreased during treatment. These results suggest that inhibition of converting enzyme activity by captopril induces a reduction in arterial pressure through a reduction in total peripheral resistance. There was no evidence of an appreciable reduction in sympathetic nervous system activity during therapy.

Adult↗
PubMed1982

The acute and chronic hypotensive effect of labetalol and the relationship with pretreatment plasma noradrenaline levels.

1 Labetalol 100 mg was given intravenously to 27 patients with essential hypertension (12 males, 15 females; WHO I-II; age range 30-66 yr; on average, a significant reduction of blood pressure was observed within 5 min (P less than 0.001). Average heart rate was also reduced significantly (P less than 0.01). 2 In 18 patients haemodynamic measurements were performed (dye-dilution or thermodilution technique): blood pressure reduction was related to peripheral vasodilatation, as cardiac index remained unmodified. 3 The absolute and percentage decrease of blood pressure, heart rate and total peripheral resistance after labetalol 100 mg intravenously, was significantly greater in the patients with higher baseline plasma noradrenaline concentration values. 4 In 12 out of 27 patients labetalol was given orally for 2 months (dose range 300-1200 mg); the pattern of blood pressure and heart rate changes after oral therapy were comparable to those observed after acute administration of the drug. 5 The degree of blood pressure and heart rate reductions after oral labetalol was also significantly related to pretreatment basal noradrenaline concentration.

Administration, Oral↗
PubMed1982

Aortic rigidity and plasma catecholamines in essential hypertensive patients.

Aortic rigidity, plasma noradrenaline and adrenaline, and hemodynamic parameters were measured in 48 essential hypertensive patients, 25 younger than 45 (Group I) and 23 of 45 years and over (Group II). Aortic rigidity was determined by the ratio of pulse pressure over stroke volume. Aortic rigidity and hemodynamic parameters were also determined after combined alpha-beta receptor blockade induced by Labetalol (mg 100 IV) or by Propranolol (mg 10 IV) plus Phentolamine (mg 10 IV). The aortic rigidity index was significantly higher in Group II, systolic arterial pressure being significantly higher. All other data, including plasma noradrenaline and adrenaline, were not significantly different in the two groups. In Group II a significant correlation (r = 0.62) was noted between aortic rigidity indexes and plasma noradrenaline values. The alpha-beta receptor blockade induced a decrease of aortic rigidity particularly in Group II, owing to a more marked decrease of systolic arterial pressure. A highly significant correlation was noted in Group II between the changes in aortic rigidity index and the basal plasma noradrenaline levels (r = 0.81). Therefore, the aortic rigidity in essential hypertensive patients older than 45 is influenced by the sympathetic nervous system activity, as judged by plasma noradrenaline levels. This influence seems related to an increase with age of aortic responsiveness to sympathetic stimulation.

Adult↗
PubMed1982

Adrenergic activity in systolic hypertension.

Basal hemodynamics and plasma catecholamines were measured in 10 patients with systolic hypertension, 7 males and 3 females, aged 38-69 years (Group 1), and in 10 patients with systolic and diastolic hypertension, 7 males and 3 females, aged 40-65 years (Group 2); the same measurements were repeated after acute pharmacological alpha and beta-blockade with Labetalol, 100 mg iv, or Propranolol, 10 mg iv, plus Phentolamine, 10 mg iv. In patients of Group 1 plasma noradrenaline was inversely related to systolic arterial pressure and to stroke index and was directly related to heart rate. In patients of Group 2 plasma noradrenaline was directly related to systolic arterial pressure. After acute alpha and beta-blockade the degree of reduction of systolic arterial pressure was directly related to basal plasma noradrenaline in both groups; systolic arterial pressure was reduced to normotensive levels in 5 patients of Group 1 who had high basal plasma noradrenaline values. These results confirm some of our previous findings and suggest that in some patients with systolic hypertension adrenergic activity is increased and may have a significant role in maintaining high blood pressure values.

Aged↗
PubMed1982

Antihypertensive and humoral effects of verapamil and nifedipine in essential hypertension.

The aim of this study was to investigate and compare the effects of two calcium antagonist drugs, verapamil (VER) and nifedipine (NIF), on blood pressure (BP), heart rate (HR), plasma catecholamines (pCA), renin (PRA), plasma aldosterone (pALD), and plasma volume (PV) in a group of patients with mild to moderate essential hypertension. In 12 hypertensive patients on a fixed normal sodium and potassium intake, VER (80 mg t.i.d., per os) first and then NIF (10 mg, t.i.d. per os), or vice versa according to a random sequence, were each given for 8 days, with an interval of 5 days between the two treatments. Both NIF and VER significantly reduced BP (p less than 0.001); this reduction was quantitatively similar in both treatment schedules. Supine and standing PRA, pALD, and PV were not significantly affected by VER or NIF. HR and pCA were unchanged after VER, whereas they were significantly increased (p less than 0.05, at least) mainly in standing position after NIF treatment. The antihypertensive and metabolic effects of VER (80 mg t.i.d.) and NIF (10 mg t.i.d.) were maintained after chronic treatment (4 months with VER in 10 patients and 2 months with NIF in 12 patients). After 2 months of treatment with VER (160 mg t.i.d.) in 18 patients, BP was further reduced, while pCA were slightly increased. In conclusion, VER and NIF are effective and equipotent antihypertensive agents that do not induce significant renin stimulation or fluid retention; adrenergic stimulation seems to be greater with NIF, which should be taken into account in the clinical use of these drugs.

Adult↗
PubMed1981

Effects of prizidilol (SKF 92657) on blood pressure, haemodynamics, sympathetic nervous system activity and plasma volume in essential hypertension.

1. The antihypertensive effect of 4 weeks' treatment with prizidilol (SKF 92657) (mean dosage 520 mg once or twice daily) was studied in ten essential hypertensive patients. 2. Both systolic and diastolic blood pressure were significantly reduced in all cases. Supine heart rate did not change, and in the erect position heart rate was significantly lowered. 3. Blood pressure reduction was due to peripheral vasodilatation, as the cardiac index increased after 4 weeks of prizidilol treatment. 4. After prizidilol plasma noradrenaline and adrenaline increased significantly, and PRA and plasma aldosterone were reduced. Although plasma volume increased, body weight did not change. 5. Cardiac performance, as evaluated by the PEP/LVET ratio, improved after treatment with prizidilol.

Adult↗