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Biomedical subjects

A Pirrelli

Publications and source records attributed to A Pirrelli.

At least 55 records · Page 3Linked to original sources
PubMed1993

Stress response and antihypertensive treatment.

Results from many studies suggest that the central nervous system may play an important role in enhancing and maintaining sympathetic, metabolic and haemodynamic effects in patients with hypertension. Likewise, emotional and mental stresses may provoke phasic and sustained adrenergic responses in normotensive and untreated hypertensive patients. Because the various antihypertensive medications have different mechanisms of action, and elicit different neurovegetative responses, it is useful to distinguish between the effects of different treatments on sympathetic activity. To identify the effect of stress on sympathetic reactivity, we evaluated the extracardiovascular and haemodynamic responses to various stressor agents using noninvasive techniques. This psychophysiological approach allowed us to standardise stress, to identify individual cardioneurovegetative responses both before and during treatment, and to establish the effects of various treatments on the cardioneurovegetative response. The extracardiovascular psychophysiological response of patients with a family history of hypertension and of normotensive patients who later became hypertensive was characterised by an inability to recover after mental challenge. Therefore, prolonged sympathetic activity resulting from mental stimulation may contribute to the development of hypertension. Antihypertensive medications affected sympathetic reactivity differently. For example, nifedipine worsened sympathetic reactivity, while verapamil was able to correct abnormal neuroadrenergic responses. Furthermore, verapamil was successfully combined with enalapril in patients whose hypertension was resistant to monotherapy with the angiotensin converting enzyme (ACE) inhibitor. Therefore, the functional and structural consequences of sympathetic stimulation resulting from daily activation and pharmacological blood pressure adjustments are important in hypertensive patients, because they may have abnormal sympathetic reactivity to various stimuli.

Antihypertensive Agents↗
PubMed1993

[Clinical hemorrheology and arterial hypertension].

In order to have a good haemorheological approach to hypertensives, we have put together a review with haemorheological subjects and with the relationships between plasmatic and haematic viscosity and hypertension in relation to pathophysiology, diagnosis, prognosis and treatment. In this review we deal with: (1) Clinical haemorheology. (2) Haematic viscosity. (3) The relationship between haemorheology and hypertension and between antihypertensive drugs and haemorheology. The study of viscosity and erythrocytes deformability, and of erythrocytes and platelets stickiness could pharmacologically correct the haemorheological disorders which can be some of the causes of hypertension.

Antihypertensive Agents↗
PubMed1993

[Glyco-lipid changes in hypertensive diabetic patients undergoing treatment with nifedipine and captopril].

Atherosclerosis in diabetic subjects is improved by the reduced repair capacity of endothelial damage and by the increased platelet aggregation, peculiar to diabetic pathology. The contemporary presence of high blood pressure, diabetes and lipoidoproteinosis, increasing the possibility of cardiovascular damage, also under well-controlled blood pressure values, certainly increases the risk of atherosclerosis. However we have valued the presence of lipoidoproteinosis in 52 of our diabetic-hypertensive patients in a follow-up of 40 months. The patients have been split in to two groups of 26 patients each, one being treated with nifedipine, the other to with captopril. The data obtained have been compared with the data for the two control groups (non diabetic patients). The selection has been carried out according to established criteria. We have investigated: glycaemia, total cholesterol, HDL-C, LDL-C, triglycerides, tot. Chol./HDL-C, LDL-C/HDL-C. During follow-up the blood pressure values were significantly reduced (p < 0.01) (captopril: delta SBP = -13.88, delta DBP = -12.38, nifedipine: delta SBP = -22.03, delta DBP = -21.35). In the nifedipine group lipoidoproteinosis has been more marked: delta% glicaemia = +17.69, delta% cholesterolemia = +20.11; delta% CFR = +18.57; LDL-C = +35.11; delta% VRF = +34.61, while in the patients treated with captopril we have had the following results: delta% glycaemia = +15.43; delta% cholesterolemia = +16.36; delta% LDL-C = +26.68. The control group with nifedipine treatment have shown only increased values of cholesterolemia: delta% = +4.80, moreover in the control group treated with captopril we have observed a reduction of VRF: delta% = -15. A significant relationship between total cholesterolemia and glycaemia in the group with nifedipine treatment (p < 0.01) and captopril (p < 0.01) has been reported. This study could appear to underline the autonomic nervous system activation by nifedipine which does not affect lipoidoproteinosis in diabetic hypertensive subjects. This would seem to confirm on the contrary, the utility of captopril in the treatment of atherosclerotic subjects, as diabetic hypertensive patients.

Adult↗
PubMed1992

Borderline hypertension: relationship between job and psychophysiological profile.

To identify relationships among hypertension, job and cardiovascular reactivity we studied 81 borderline hypertensives divided into labourers (L), white collars (W) and managers (M). After behavioral analysis, they underwent 4 tests: arithmetic, Sacks, acoustic, electric. Along the entire sitting, muscular contraction, skin conductance (SCL), peripheric temperature (THP), SBP, DBP and HR were taken, every 30". Depression, obsessive-compulsive, anxiety and neurotic traits were found in W. SBP, DBP and HR were not significantly different. Failed recovery curves of SCL were identified in M and W, but the presence of abnormal response profile, of both, SCL and THP, only in W. This autonomic dysreactivity, previously recognized as a possible characteristic of the prehypertensive condition, could uncover the role of certain work stressful condition to increase the sympathetic drive underlying hypertension.

Adult↗
PubMed1992

[Left ventricular hypertrophy: physiopathological signs using a hemodynamic and cardio-autonomic approach].

The presence of left ventricular hypertrophy (LVH) in either hypertensives -H- or in normotensives -N-, suggests that not only blood pressure is determining this anatomic change, but various factors, as neural or endocrine ones, could be involved in its genesis. In order to evaluate the role of sympathetic dys-reactivity on LVH, we studied three groups of subjects: a) 12 -H- (SBP 159+/-9; DBP 99.6+/-7; FC 80+/-7) with LVH, diagnosed by echocardiogram. b) 12 -N- (SBP 138.2+/-8; DBP 83+/-2; FC 75.6+/-4) with LVH. c) 12 -N- (SBP 136.6+/-11; DBP 81.8+/-5; FC 76.3+/-5) without LVH. Using computer interfaced equipment, we measured beat to beat, hemodynamic and extra-cardiovascular autonomic functions, during a session of stressors (Mental Arithmetic, Color Word Stroop, Cold Pressure and Handgrip Tests), preceded and followed by 10' of observation. Among the various considered indexes, we evaluated the Percentual Total Activity Index (PTAI), as percentual total activity change + percentual total recovery change. Our findings point out that the PTAI of N with LVH is significantly higher for SCL, PHT, HR, SV, CO, TPR than either in H with LVH or N without LVH. These data seem to demonstrate a prolonged reactivity in N without LVH and are according to the hypothesis that LVH could also be supported by a hyper-adrenergic state with sympathetic dys-reactivity, independently from high blood pressure values.

Heart Conduction System↗
PubMed1991

Comparison of the new alpha 1-blocker alfuzosin with propranolol as first-line therapy in hypertension.

The new alpha 1-blocker alfuzosin was compared with propranolol as monotherapy for hypertension in a double-blind, parallel group study of 8-week duration in 40 patients with essential hypertension. The patients (11 males, 29 females; mean age 47.8 +/- 2.2 years in the alfuzosin group and 46.6 +/- 2.4 years in the propranolol group) randomly received either alfuzosin from 2.5 mg b.i.d. up to 10 mg b.i.d. or propranolol from 40 mg b.i.d. up to 160 mg b.i.d. according to an individualized dose-titration schedule. The two groups were comparable with respect to disease history, cardiovascular risk factors, concomitant diseases, previous treatments and end-placebo blood pressure and heart rate values. Four patients did not complete the study, two patients in the alfuzosin group: one patient because of postural hypotension and the second one because of breast cancer; and two patients in the propranolol group: one patient for inefficacy and the second one lost to follow-up. At the end of the 8-week trial the mean daily doses were 12.2 +/- 0.61 mg and 196 +/- 9.82 mg for alfuzosin and propranolol, respectively. The antihypertensive effects of the two drugs were comparable. Upright and supine blood pressures decreased significantly with both treatments from the second week on (P less than 0.001 for all BP values). At the end of the 8-week double-blind trial, 83% of alfuzosin patients and 67% of propranolol patients were normalized. The two treatments differed significantly with respect to their effect on heart rate. Alfuzosin did not induce marked changes in heart rate: only a slight increase was observed. In contrast, propranolol caused bradycardia, more marked in the upright position. Palpitations, headache, asthenia and orthostatic hypotension were reported in the alfuzosin group. Asthenia and decreased libido were reported in the propranolol group. These data prove that alfuzosin has antihypertensive effects equivalent to propranolol and it is an interesting agent for the therapy of essential hypertension. It can be used as a first agent at doses between 5 and 20 mg/day with satisfactory therapeutic response and without relevant side-effects.

Adrenergic alpha-Antagonists↗
PubMed1991

[The effects of bisoprolol and atenolol on glucose metabolism in hypertensive patients with non-insulin-dependent diabetes mellitus].

Effects of bisoprolol and atenolol on glucose metabolism in hypertensive patients NIDDM. The aim of the study was to compare the antihypertensive efficacy and the effects on glucose metabolism of a new beta 1-selective beta-blocker with high beta 1 selectivity, bisoprolol and atenolol in 12 hypertensive patients (WHO classes I e II) suffering from untreated not insulin-dependent diabetes mellitus (NIDDM). According to a cross-over design after a placebo run-in period of 4 weeks, the patients were randomly allocated to receive bisoprolol 10 mg o.d. or atenolol 100 mg o.d. for 4 weeks, with a four-week wash-out period between the two active treatments. In basal condition and after each therapy an intravenous glucose tolerance test (i.v. GTT, 20 g) was performed, with evaluation of serum glucose and insulin at 0, 15, 30, 60, 90, 120 minutes and glycosuria during the test. At the same time blood pressure, heart rate (supine, upright), ECG, laboratory tests were assessed and subjective tolerability was evaluated. The glucose and insulin responses to the i.v. GTT did not significantly change to basal condition. Similarly glycosuria did not show significative increment during the test with both beta-blocking therapies. Blood pressure and heart rate values were significantly reduced (p less than 0.001) after bisoprolol and atenolol treatment. During the study no side effects were reported and laboratory tests and ECG remained substantially unchanged. These data confirm the antihypertensive efficacy of bisoprolol and atenolol and demonstrate the absence of important effects of these drugs on glucose metabolism in hypertensive patients with NIDDM.

Adrenergic beta-Antagonists↗
PubMed1991

[Hemodynamic and psychophysiologic evaluation in hypertensive diabetic patients].

In order to evaluate a peculiar hemodynamic and psychophysiological reactivity in hypertensive-diabetics, a male population of mild essential hypertensives and mild NID hypertensive-diabetics underwent a session of tests:Arithmetic, Sacks', Cold Pressor, Hand-grip, preceded and followed by a 10' recovery period, Valsalva Manoeuver, Beat to beat, Tilt table. Along the entire session, by means of a beat to beat, non invasive computerized system, we measured some pressure, hemodynamic, and extra-cardiovascular variables. The obtained findings seem to suggest a sympathetic hyperreactivity both in HD and in H. In HD it has a particular "tropism" for peripheral vascular bed, as showed by vascular resistances and peripheral temperature responsivity; on the other hand the cardiac contractility index is more depressed than in H, suggesting that in HD, cardiac and pressor responses might be influenced by some mechanisms whose nature seem related to neither functional damage nor hemodynamic adjustments. The different profiles of the two populations seem to confirm the utility of this kind of hemodynamic, non invasive evaluation in all the pathologies where Autonomic Nervous System is involved, in order to obtain a better diagnosis approach and therapeutic treatment.

Body Temperature↗
PubMed1991

[Psychophysiologic markers of arterial hypertension].

Many studies, concerning cardiovascular reactivity in hypertensives, show contrasting data. The aim of the present study was to check, also measuring extracardiovascular variables, a procedure able to identify a peculiar characteristic of the prehypertensive phase. We studied 47 normotensives, who referred high blood pressure values, but that we did not find in our visit. The cardioneurovascular assessment was evaluated, by means of a non invasive, beat to beat technique, measuring SBP, DBP, HR, muscular contraction and skin conductance level (EMG, SCL), peripheric temperature (PT), during a psychophysiologic session. This was composed by 4 stressors (mental arithmetic and Sacks test, acoustic and electric stimulations), 5 minutes each, preceded and followed by an observation period of 10 minutes. After 18 month follow-up, we could distinguish 26 hypertensives (H), and 21 subjects maintained normal blood pressure values (N). The obtained findings showed, with statistical significance, 1) the hyperresponsiveness of SCL and PT; 2) the failed recovery, with consequent hyperdysreactivity, of SCL and PT; 3) the presence of both these phenomena in the H., while SBP, DBP and HR responses did not result a discriminative tool. These data seem 1) to reinforce the hypothesis that a hypersympathetic phase can characterize the prehypertensive stages of essential hypertension and 2) to suggest the psychophysiological approach as a useful method to diagnose prehypertension.

Acoustic Stimulation↗
PubMed1990

[Effects of long-term treatment with captopril on the isomyosin profile of the heart from SHR and Wistar rats].

Heart myosin isoforms and arterial blood pressure changes were studied in 30 SHR rats following a long-term treatment with captopril. 30 Wistar rats were included in the same trial as control. Twelve week old SHR rats with an already established hypertension and ventricular hypertrophy were orally administered with between 25 and 100 mg/Kg/die of captopril. After a ten-week treatment, animals were sacrificed and heart myosin isoforms (V1, V2, V3) analysed by polyacrylamide gel electrophoresis. Our results showed that captopril can: a) reduce blood pressure; b) reduce the cardiac hypertrophy; c) reverse the isomyosin enzymes (V1 V3) previously altered by the hypertrophy condition (V3 V1) to normal value. Furthermore we have detected an increase of V myosin isoform in SHR rats (35%) and to a lower extent in treated Wistar rats (17%). Since SHR and Wistar rats usually do not express V isoform, our results suggest that captopril may be responsible for this phenomenon by acting directly on myocardial cells.

Animals↗
PubMed1990

[Effects of long-term treatment with calcium antagonists on the isomyosin composition of the hearts of spontaneously hypertensive rats].

Purpose of this study was to evaluate the long-term effects of treatment by calcium antagonists on blood pressure (BP) and cardiac isomyosins of SHR. From the fourth week of life we studied 40 SHRs and 20 Wistars in standard conditions and at the twelfth week, when SHRs already showed high BP and left ventricular hypertrophy (LVH), we treated 10 of them by nifedipine (N) (30 mg/Kg/die) and 10 by verapamil (V) (100 mg/Kg/die). BP was measured by tail-cuff technique. At the tenth week of treatment when the rats were sacrificed, LVH index and isomyosinic profile were evaluated. The results obtained demonstrate that: at the twenty-second week, V1 was 17% in untreated SHR, 90% in N and 75% in V while V3 was 80% in the untreated group, 8% in N and 15% in V, respectively. In conclusion, the treatment by calcium antagonists reduced BP and LVH re-establishing the predominance of V1 on V3.

Animals↗
PubMed1990

[Reactivity of the aorta from spontaneously hypertensive rats before and after endothelial removal].

In the present study the mechanic activity of SHR and Wistar rat's aorta was evaluated, in vitro, after stimulation by chloride of potassium, phenylephrine, norepinephrine, histamine, serotonin and acetylcholine, before and after the removal of the endothelium. The aorta rings of the rats were taken before the development of the hypertensive state (7th week) and at 18th week (when the SHR rats already showed established hypertension starting since IXth week of life), and successively suspended in a bath for isolated organ. The mechanic activity was measured by isometric transductor. The obtained findings show an increased sensitivity, in SHRs, to (K+), NA and FeE, if these are compared with the control group, since the prehypertensive stage (7th week). The removal of the endothelium didn't modify the response amplitude to K in both the breeds, while the maximum response amplitude, provoked by NA and FeE, significantly increased in SHRs compared to controls. The relaxation induced by the vasodilator agents (Ach-H-5HT) was completely absent in the SHR rats' aorta with established hypertension. In conclusion, these results suggest a functional deterioration of the endothelial cells, in the hypertensive animals, that could contribute to increase the peripheric vascular resistances observed during hypertension.

Animals↗
PubMed1989

Neurovegetative assessment in subjects with a risk for hypertension.

Cardiacneurovegatative assessment was studied in 60 subjects divided into three groups consisting of 20 normotensive subjects without familial hypertension, 20 normotensive subjects with familial hypertension, and 20 patients with mild hypertension. Cardiacneurovegetative function was investigated by evaluations of these parameters: systolic, diastolic, and mean blood pressure, heart rate, skin temperature, skin conductance, and muscular contraction. These measurements were taken before and after psychological stress (mathematical, Sacks' incomplete sentences, electrical, auditory) and after physical stress (cold, hand grip, head-up tilt, lying, and standing). The results showed a significant difference of the psychophysiologic profiles among the three groups. On the contrary, the cardiovascular variables were not very sensitive or well-discriminating, especially when response amplitude was considered. In conclusion we propose the hypothesis that identification of the psychophysiologic profile in certain individuals may be a better marker for future development of hypertension in subjects with a genetic risk.

Adult↗
PubMed1989

[Changes of cardiac myosin in spontaneously hypertensive rats and control rats, during the various stages of development of essential arterial hypertension].

The aim of this research was to assess left ventricular myosin alterations of Sh, rats during the various phases in which primitive hypertension developed. Two groups of animals were examined: one comprised spontaneously hypertension rats (Shr) and the other controls. Both groups were studied from the 5th to 31st week of life. The Shrs became hypertensive at 9 weeks of age. The animals were sacrificed at: 5-7-9-12-16-24-31 weeks of age. The left ventricles were separated from their hearts and native myosin in non dissociated conditions was then obtained by polyacrylamide gel electrophoresis; heavy chains and light chains were separated with S.D.S. One of the findings showed that in the control rats the myosin iso-enzyme V1 always prevailed over the myosin iso-enzyme V3 during all the stages of life examined. In the Shrs, starting from the iso-enzyme V3 increased proportionally. The heavy chains showed the same behavior as the native protein while there were no significant differences for the light chains in both groups of animals. In conclusion, our findings show that the structural and biochemical compensation variations which several authors have demonstrated in other conditions of experimental hypertension occur in Sh rats as well.

Animals↗
PubMed1989

[In vitro reactivity of the aorta of SHR rats and Wistar rats, in the various developmental phases of arterial hypertension: role of the endothelium].

The mechanical reactivity of SHR and Wistar rats' aortas was evaluated, in vitro, after stimulation by potassium chloride (K+), phenylephrine (Phe), norepinephrine (NE), histamine (H), serotonin (5-HT) and acetylcholine (Ach), before and after the removal of the endothelium. The aortic rings were taken at different ages and stages of the hypertensive state (that in the SHRs started at the ninth week of life) and successively suspended in a bath for isolated organs. The mechanical activity was measured by isometric transducers. In SHR rats an increased sensitivity to K+, NE and Phe compared with the control group, and preceding the hypertensive stage, was found. The removal of the endothelium did not modify the response amplitude to K in both the breeds, while the maximum response amplitude, provoked by NE and Phe, significantly increased in SHRs compared to controls. The relaxation induced by vasodilator agents (Ach, H, 5-HT) was significantly reduced in the SHR rats' aortas with initial hypertension (12th week) if compared with Wistar rats at the same age. The release response was completely absent in the SHR rats' aortas with established hypertension (18th week). In conclusion, these results suggest that, in hypertensive rats, a functional deterioration of the endothelial cells occurs: this may contribute to the increase in peripheral vascular resistance observed during hypertension.

Animals↗