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Biomedical subjects

C Cardillo

Publications and source records attributed to C Cardillo.

At least 37 records · Page 2Linked to original sources
PubMed1994

Platelet alpha 2-adrenoceptors and diurnal changes of platelet aggregability in hypertensive patients.

OBJECTIVE: To analyse whether platelets from hypertensive patients have an increased responsiveness to aggregating agents during morning hours and whether these changes might be related to concurrent changes in platelet membrane alpha 2-adrenoceptor characteristics, plasma catecholamine and cortisol levels, and blood pressure values. DESIGN AND METHODS: Blood samples from 14 mild-to-moderate essential hypertensive males were collected in the morning (0700-0900 h) and the evening (1900-2100 h) to determine platelet aggregability responses to adrenaline and ADP, platelet alpha 2-adrenoceptor number and binding affinity to [3H]-yohimbine, plasma catecholamines and cortisol. During the same day patients underwent 24-h ambulatory blood pressure monitoring. RESULTS: The lowest concentration of adrenaline required to induce biphasic aggregation was significantly lower in the morning than in the evening, indicating an increased morning platelet aggregability to adrenaline; the minimum ADP concentration inducing aggregation was similar in morning and evening samples. There were no significant differences between morning and evening samples in platelet alpha 2-adrenoceptor number and binding affinity. Plasma adrenaline, noradrenaline and cortisol levels were higher in the morning than in the evening, but no correlation was observed between hormonal changes and the morning increase in platelet sensitivity to adrenaline. Ambulatory blood pressure recording showed abrupt morning elevations in systolic and diastolic blood pressures over sleeping values. However, morning blood pressure readings were not significantly different from those recorded during the rest of the day and in the evening. The morning rise in mean arterial pressure displayed a significant inverse correlation with the increased platelet sensitivity to adrenaline that was observed during the same hours. CONCLUSIONS: The results indicate that the increased morning responsiveness to adrenaline that was observed in platelets obtained from hypertensive patients does not appear to be mediated by changes in the characteristics of platelet membrane alpha 2-adrenoceptors, but morning blood pressure elevations might play some role in inducing this platelet hyper-reactivity.

Adenosine Diphosphate↗
PubMed1993

Comparison of the effects of terazosin and enalapril on laboratory stress testing blood pressure in patients with essential hypertension.

It is the current opinion that an ideal antihypertensive drug should reduce blood pressure (BP) not only at rest but also during stressful situations. The current study was aimed to compare the effects of the selective alpha 1-adrenergic blocker terazosin (5 mg once daily) and of the angiotensin-converting enzyme inhibitor enalapril (20 mg once daily) on cardiovascular response to a set of standardized laboratory stressors, such as mental arithmetic, handgrip test and cycle ergometry, in a group of 16 essential hypertensive patients. The study was a randomized, double-blind, cross-over trial preceded by a placebo run-in period. Terazosin and enalapril had a comparable effect on resting BP, reducing systolic (SBP) and diastolic (DBP) blood pressure from 159.5 +/- 13.9/101.6 +/- 8.8 mm Hg during placebo by 7.8%/6.7% and by 11.3%/10.2%, respectively. The "response" rate to the two treatments was approximately the same, being 69% and 75% after terazosin and enalapril, respectively. During mental arithmetic, from an average of 181.6 +/- 17.8/118.6 +/- 11.5 mm Hg during placebo, BP was reduced by 11.5%/7.9% after terazosin and by 13.6%/8.5% after enalapril; during handgrip test, BP decreased from 207.2 +/- 22.2/142.2 +/- 13.6 mm Hg by 7.3%/8.4% after terazosin and by 7.7%/7.1% after enalapril; finally, during cycle ergometry, terazosin and enalapril lowered BP by 5.4%/6.7% and 7%/3.1%, respectively, from a placebo value of 215.5 +/- 17.3/127.6 +/- 11.2. No significant difference in antihypertensive efficacy was observed between the two drugs, either at rest and during stress testing.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic alpha-Antagonists↗
PubMed1993

Psychophysiological reactivity and cardiac end-organ changes in white coat hypertension.

This study aimed 1) to assess whether patients with an exaggerated blood pressure response to the doctor's presence ("white coat" effect) also display a pattern of enhanced blood pressure reactivity to mental stress and physical exercise and 2) to determine the presence of left ventricular structural and filling abnormalities in patients with white coat hypertension. We studied 56 (40 men) consecutive patients (mean [SD] age, 46.4 [9.1] years) whose clinic blood pressure was repeatedly high. Patients were classified as having white coat hypertension (n = 20) if both their mean daytime (from 7 AM to 11 PM) ambulatory systolic and diastolic blood pressures were less than 134 and 90 mm Hg, respectively. Patients were considered to have persistent hypertension (n = 36) if daytime systolic blood pressure was 134 mm Hg or more or diastolic blood pressure was 90 mm Hg or more. Eighteen subjects with clinic blood pressure lower than 140/90 mm Hg served as a normotensive control group. Blood pressure reactivity from baseline to mental arithmetic, isometric handgrip, and cycle ergometry did not display any difference among the three groups. The white coat hypertensive group had left ventricular mass index lower than the persistent hypertensive group but higher than the normotensive group. Doppler indexes of left ventricular diastolic filling displayed similar abnormalities in the white coat and persistent hypertensive groups compared with the normotensive group.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1992

Effects of celiprolol on cardiovascular reactivity to laboratory stressors in patients with hypertension.

An ideal antihypertensive drug should reduce blood pressure not only at rest but also during stressful situations. To test whether this criterion is fulfilled by celiprolol, a new beta 1-selective adrenergic blocker drug with peripheral vasodilating activity, we examined the effects of its oral administration on cardiovascular reactivity to laboratory stressors in 18 patients with essential hypertension, according to a placebo-controlled crossover design. In the 12 patients classified as "responders," celiprolol significantly reduced resting systolic and diastolic blood pressure (p less than 0.05 for both). Compared with placebo, celiprolol induced a blood pressure reduction from 179.4 +/- 16.9/119.5 +/- 12.4 mm Hg to 160.7 +/- 12.6/109.4 +/- 3.1 mm Hg during mental arithmetic; from 200.9 +/- 20.7/139.2 +/- 11.9 mm Hg to 184.1 +/- 16.4/127.6 +/- 12.1 mm Hg during handgrip test; from 212.8 +/- 18.5/126.2 +/- 14.2 mm Hg to 185.9 +/- 18.2/117.1 +/- 15.2 mm Hg during cycle ergometry. Our data suggest that in the majority of treated patients celiprolol is effective in reducing blood pressure not only at rest but also during a variety of stressful events, thereby ameliorating the impact of recurring stress-induced increases of blood pressure on the cardiovascular system.

Adult↗
PubMed1992

Relationship of stress testing blood pressure with electrocardiographic and fundoscopy indices of hypertensive end-organ damage.

In our study we tested firstly, whether BP changes induced by laboratory stress testing could be better related than resting blood pressure (BP) to hypertensive target-organ damage (TOD) and secondly, whether an exaggerated reactivity to stress testing might be associated with an increased prevalence of TOD. In 49 untreated essential hypertensives, BP measured at sitting rest and during a variety of stressful situations was related to the presence of TOD, assessed by electrocardiography (ECG) and fundoscopy examination. The degree of TOD was significantly correlated to resting SBP; neither SBP at peak of isometric or dynamic exercise, nor SBP during mental test showed a greater correlation with TOD than resting SBP (NS). A large variability of individual's level of BP reactivity across the different laboratory tests was observed. Patients were arbitrarily dichotomised into groups according to a hyperreactive or normoreactive response to each stress testing; patients classified as hyperreactive (SBP increase greater than upper 95% confidence limit) did not disclose a greater rate of cardiac and ocular damage than normoreactors (NS). In conclusion, stress BP does not increase the strength of relationship with TOD compared to resting BP. Cardiovascular reactivity differs according to the laboratory stimulus employed and an exaggerated BP rise during stress testing is not associated with an increased rate of TOD.

Adult↗
PubMed1990

A discrepancy between platelet alpha 2-receptor density and functional circulatory changes in hypertensives.

To investigate whether differences exist in peripheral alpha 2-adrenoceptors between normotensive and hypertensive subjects, we determined platelet alpha 2-adrenoceptor density in 10 (7 males) untreated essential hypertensives (mean age of 51.1 years, range of 44-59 years) and in 10 age- and sex-matched normotensive controls. Moreover, in hypertensive patients, we examined the relationship between receptor density and cardiovascular reactivity to mental arithmetic, static handgrip, and bicycle exercise, to verify the hypothesis that alpha 2-adrenoceptors might play a role in modulation of hemodynamic response to sympathetic stimuli. alpha 2-Adrenoceptor density, as calculated by binding of [3H]yohimbine to platelets, was significantly higher in essential hypertensives (314.8 +/- 38.7 fmol/mg) than in normotensive subjects (213.6 +/- 34.7 fmol/mg) (p less than 0.05), whereas receptor affinity was similar in both groups (4.0 +/- 0.5 nM hypertensives, 4.3 +/- 0.5 nM normotensives; p greater than 0.05). Mental arithmetic increased mean arterial pressure (MAP) by 21.5% from basal values and heart rate (HR) by 13.2%. During isometric exercise, MAP increased by 38.1% and HR by 24.7%, while during bicycle ergometry, mean increases in MAP and HR from baseline were of 27.2 and 54.3%, respectively. No correlation was found between platelet alpha 2-adrenoceptor density and percent changes in MAP induced by all tests, or between adrenoceptors and absolute basal and peak MAP values. Our findings suggest that in hypertensive patients, peripheral alpha 2-adrenoceptors are increased with respect to matched normotensives, but these receptors seem not to be involved in the modulation of cardiovascular adaptation to enhanced sympathetic activity.

Adult↗
PubMed1989

Heart rate variability and ventricular ectopic activity in hypertensive patients.

In order to investigate whether the severity of ventricular ectopic beats in hypertensive patients is influenced by the autonomic drive to the heart, we evaluated the relationship between the degree of dysrhythmias and 24-h spontaneous heart rate variability, an index of sympatho-vagal balance at cardiac level. Ambulatory 24-h ECG monitoring was used to examine 42 untreated essential hypertensives, previously scored for the presence and the extent of hypertensive target organ damage. No significant difference was found in the prevalence of complex ventricular ectopic beats in patients with a heart rate variability that was lower and higher than the arbitrary cut off points selected to divide subjects into groups. Neither heart rate variability nor the degree of arrhythmias was correlated with blood pressure levels, whereas the degree of ectopy was influenced by the presence of target organ damage and left ventricular hypertrophy (by ECG). Our results seem to exclude an association between dysrhythmias in hypertensives and autonomic outflow to the heart as detected by the analysis of heart rate variability.

Adult↗
PubMed1989

Effects of sustained-release verapamil on 24-hour ambulatory blood pressure and on pressor response to isometric exertion in hypertensive patients.

The antihypertensive effect of a drug should be present not only at rest, but also during usual daily activities and pressor stimuli. In our study, we tested the impact of a new formulation of sustained-release (SR) verapamil (240-mg tablets), given once or twice daily, on 24-h ambulatory blood pressure (BP) and on pressor response to isometric exercise (handgrip). Fourteen mildly to moderately essential hypertensive patients were included in a single-blind placebo-controlled trial. The mean titrated dose of verapamil required to normalize office BP was 430 +/- 28 mg/day. Mean 24-h waking (7 a.m.-11 p.m.) and sleeping (11 p.m.-7 a.m.) blood pressures were significantly lower after verapamil than after placebo. The absolute levels of BP achieved at peak of handgrip (30% of maximal voluntary contraction for 3 min) were significantly reduced by verapamil with respect to placebo. However, due to the lower starting values, the pressor increment to the isometric work was not significantly modified by the active treatment. In conclusion, SR verapamil seems to provide a blood pressure lowering effect during all times of the day. It attenuates the surges in BP associated with handgrip exercise.

Adult↗
PubMed1989

Cardiovascular reactivity and plasma prolactin response to mental stress in normals and hypertensives.

Central dopaminergic activity (CDA) may be involved in blood pressure control as a negative modulator of sympathetic outflow. In this study the plasma PRL changes produced by mental stress (a colour-word conflict test, CWT) were investigated in normals (NT, n.15) and stable hypertensives (HT, n.16) and the PRL response, as a possible index of CDA was correlated to the cardiovascular and the plasma renin activity (PRA) responses as indexes of peripheral sympathetic outflow. A significant (p less than 0.05) slight decrease in mean values of PRL was observed in normals after the CWT but no change was found in hypertensives. No correlation was found between the PRL responses to CWT and the maximal mean arterial pressure changes or the PRA changes whether the groups were considered separately or together. These findings indicates that PRL does not appear to be a reliable index of the CDA involved in blood pressure control.

Adult↗
PubMed1989

[Usefulness of sublingual captopril in hypertensive emergencies. Preliminary results].

The aim of this study, whose preliminary findings are reported, is to evaluate the efficacy of captopril, administered by a sublingual route, in the treatment of hypertensive emergencies. Captopril has been given by this route to 20 hypertensive patients while these had an ongoing hypertensive crisis (defined as a systolic arterial pressure above 200 mmHg associated with a diastolic arterial pressure above 115 mmHg). Arterial pressure has been measured after 5, 20, 10, 15, 30, 45, 60 and 120 min. For 8 patients it has been measured until the eighth hour. Results were the following: a satisfactory control of hypertensive crisis in 85% of patients, as stated by a slight but significant drop of arterial pressure after 10 min (15/10 mmHg; p less than 0.05) and by a maximum antihypertensive effect after 30 min (57/39 mmHg; p less than 0.001); an antihypertensive effect was evident until 6 hours after the administration of the drug; a positive correlation between the antihypertensive effect and pretreatment levels of arterial pressure and plasma renin activity; drug was free from relevant side effects; sublingual captopril can be considered an efficacious, easy to use and valuable tool in the treatment of hypertensive emergencies.

Administration, Sublingual↗
PubMed1989

Effects of calcium channel blockers on the endothelial release of von Willebrand factor after exercise in healthy subjects.

Von Willebrand factor (vWF) is known to play a relevant role in the development of atherosclerotic lesions by promoting platelet adhesion to injured endothelial cells. An increase in cytosolic calcium has been shown to be associated with the in vitro release of vWF from endothelial cells. The aim of our investigation was to examine the effect of some calcium channel blockers on the release of vWF antigen (vWF:Ag) induced by exercise in two groups of eight healthy subjects during a randomized crossover study between placebo and calcium channel blockers. Placebo and verapamil (80 mg) or nicardipine (10 mg) were given orally at an interval of 2 weeks three times on the day before and once on the morning of the study day. Measurements of plasma vWF:Ag were made at rest and after a progressive maximal exercise on a cycloergometer. A significant increase in absolute values of vWF:Ag was observed after exercise in the subjects given a placebo in both verapamil (0.397 +/- 0.074 U/ml) and nicardipine (0.327 +/- 0.036 U/ml) groups, p less than 0.05. With use of verapamil the rise in vWF:Ag was blunted and not significant (0.123 +/- 0.081 U/ml) whereas a larger increase in vWF:Ag was found in the subjects given nicardipine in comparison with placebo (0.593 +/- 120 U/ml; p less than 0.05). No correlations were observed between exercise-induced changes in systolic or diastolic blood pressure, heart rate, blood lactate level, or pH and vWF:Ag changes in the subjects given a placebo or in those given calcium channel blockers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Twenty-four-hour blood pressure monitoring after a single dose of sustained-release verapamil.

The antihypertensive effect of a single dose of 240 mg sustained-release (S-R) verapamil was investigated by ambulatory blood pressure (BP) monitoring in 13 patients with mild to moderate essential hypertension. Following a 2-week washout period, 24-hour BP monitoring was carried out with a Spacelabs ICR 5300 device following random administration of a tablet of S-R verapamil or placebo; BP recording was repeated after crossover 3 to 7 days later. Average whole-day systolic and diastolic BPs were significantly lower after verapamil (130.1 +/- 2.6/87.1 +/- 1.2 mmHg) than after placebo (142.1 +/- 3.3/95.8 +/- 2.1 mmHg) (p less than 0.01). Mean waking BP was 146.4 +/- 3.6/99.1 +/- 2.2 mmHg after placebo and 135.2 +/- 3.3/90.5 +/- 1.7 mmHg after verapamil (p less than 0.01); during sleeping hours BP was 133.8 +/- 3.1/88.7 +/- 2.6 mmHg following placebo and 122.2 +/- 2.3/80.9 +/- 1.8 mmHg following verapamil (p less than 0.01). Blood pressure profile was significantly reduced by verapamil up to 20 hours after tablet administration, while from 21 to 24 hours after drug intake BP values were similar to placebo. Response to verapamil was not correlated to the pretreatment BP values and to the patient's age. In summary, this study suggests that acute administration of 240 mg S-R verapamil in hypertensive patients produces a BP reduction during 24-hour, daytime, and nighttime periods. The hypotensive efficacy is preserved for many hours after tablet intake and seems to be due to individual variation in cardiovascular reactivity to the drug.

Adult↗
PubMed1988

Effect of sustained-release verapamil therapy on the blood pressure at rest and on the pressor response to isometric exertion in hypertensive patients.

The effect of a new formulation of verapamil sustained release (SR) 240 mg tablets on resting blood pressure (BP) and on the pressor response to isometric exertion have been examined in a single-blind, placebo-controlled, cross-over study in 12 hypertensive patients (mean age 45 years). SR verapamil and placebo were administered every 12 h for 6 consecutive weeks. At the end of each period of treatment BP and heart rate (HR) were measured at rest and during isometric exercise, performed as a handgrip (HG) test for 3 min at 30% of the maximum voluntary contraction. There was a significant reduction in resting systolic and diastolic BP, with no change in HR. BP and HR at peak exercise were lower after verapamil than after placebo, but the maximal absolute increase did not change during verapamil therapy. The results are compatible with a role of SR verapamil b.d. in reducing resting BP in hypertension, and in lowering very high pressure at the peak of a HG test, without modifying the physiological reactivity of cardiovascular system.

Adult↗
PubMed1988

Casual versus 24-hour ambulatory blood pressure recording in the evaluation of chronic administration of sustained-release verapamil.

Although ambulatory blood pressure monitoring has been used widely for the evaluation of antihypertensive treatment, little information is available regarding the comparison between this method and casual BP measurement during drug trials. In our study, we tested the efficacy of a new formulation of verapamil, 240 mg sustained-release tablets, and compared the degree of BP reduction as detected by casual (standard mercury manometer) and by 24-hour ambulatory recording (Spacelab ICR 5300). A statistically significant fall in casual BP was observed after verapamil with respect to placebo. Moreover, 24-hour, waking and sleeping ambulatory BPs were significantly reduced by verapamil. The mean BP reduction was similar for office (20.1/16.1 +/- 4.3/3.1 mmHg) and for day-time ambulatory monitoring (13.4/10.7 +/- 4.2/1.9 1.9 mmHg), but no correlation was found between BP fall recorded by the two techniques for individual subjects. This study suggests that sustained-release verapamil is an effective antihypertensive drug. Individual mean BP reduction outside the clinic may not be predicted from office readings and therefore ambulatory BP recording seems to provide a better basis for testing the efficacy of drugs.

Adult↗
PubMed1987

Plasma markers of endothelial cells and platelet activation following handgrip in normals and hypertensive patients.

Endothelial injury and platelet activation may be involved in the pathogenesis of hypertensive vascular disease. The aim of this study was to evaluate the change in endothelial cell and platelet activation plasma markers after an acute physiological increase in blood pressure. Plasma renin activity (PRA), serum angiotensin-converting enzyme (ACE), plasma factor VIIIR:Ag, and plasma beta-thromboglobulin (BTG) were determined before and after handgrip in subjects with borderline (n = 8) and established (n = 11) hypertension and in age-matched normal volunteers (n = 10). A significant mean increase in ACE, factor VIIIR:Ag, and BTG was observed after handgrip in all groups of subjects. A greater response in BTG changes was found in hypertensive subjects when compared with normal subjects. No correlations were found between the blood pressure response after handgrip and the handgrip-induced changes in plasma markers of endothelial cells and platelet activation. Changes in endothelial cells and platelet activity occurring after handgrip did not appear to depend on the associated blood pressure elevations.

Adult↗
PubMed1987

[Effect of somatostatin on peripheral circulation. Preliminary study].

Somatostatin is a cyclic tetradecapeptide widely distributed in the human cells; it has many physiological effects. Synthetic somatostatin, actually employed in some clinical conditions, was administered intravenously to normal and arteriopathic subjects. Rheography and plethysmography of lower limbs were performed before, during and after administration. A marked improvement of blood flow and a reduction of heart rate was observed after somatostatin infusion. Some hypotheses about the mechanism of action of somatostatin are discussed, especially the action on the sympathetic nervous system or the calcium-antagonist effect on the blood vessels.

Adult↗
PubMed1987

Cardiovascular reactivity, plasma markers of endothelial and platelet activity and plasma renin activity after mental stress in normals and hypertensives.

Endothelial injury and platelet activation, mechanisms known to be involved in vascular lesions, may promote the development of cardiovascular disorders possibly associated with mental stress. Plasma markers of platelet activation (beta-thromboglobulin, BTG) and of endothelium activity (factor VIII/von Willebrand factor, FVIII/vWf) and plasma renin activity (PRA) were determined in 17 healthy normotensive volunteers and in 21 hypertensives without target-organ damage before and after mental stress (a colour-word conflict test). The aim of the study was to compare cardiovascular reactivity with the stress-induced changes in platelet and endothelium activity. Individual responses in BTG and factor FVIII/vWf after the colour-word conflict test were markedly different, but significant mean increases were observed in both groups with no difference in the degree of response and in the percentage of responders. No correlations were found among the changes in plasma variables or between cardiovascular reactivity (systolic and diastolic blood pressure and heart rate) and the changes in BTG, FVIII/vWf and PRA. These findings suggest that hypertensive patients do not have an abnormal platelet or endothelium reactivity to mental stress, at least when the disease is free of vascular complications. This dissociation of stress-induced variability in BTG and FVIII/vWf and cardiovascular reactivity indicates that these indices could be used as independent markers of mental stress.

Adult↗