Inhibition by dopamine of the neurotransmission in the rat vas deferens.

The effects of alpha-adrenoceptor and dopaminoceptor agonists and antagonists were investigated on presynaptic receptors in the prostatic portion of rat vas deferens. The variable studied was the early component (250 msec) of the motor response elicited by field stimulation (single pulses). All the experiments were carried out in the presence of cocaine 30 mumol/l and hydrocortisone 28 mumol/l so as to block the sites of amines loss and 1-propranolol 0.3 mumol/l to block beta-adrenoceptors. Clonidine, noradrenaline (NA) and dopamine (DA) inhibited the motor response in a concentration-dependent manner. DA was 10 and 10(4) times less potent than NA and clonidine respectively. The selective D2 agonist, LY 141865, failed to inhibit the motor response even at a high concentration (30 mumol/l). Yohimbine (0.1, 0.3 and 1 mumol/l) antagonized competitively the effect of clonidine, NA and DA showing similar - log KB values (7.57; 7.68 and 7.09 respectively). Likewise, idaxozan (0.03 mumol/l) blocked the inhibitory effect of DA in the same order of potency (- log KB = 7.81). On the other hand, pimozide 0.21 mumol/l and Schering 23390 3 mumol/l antagonized the inhibitory effect of DA, showing a lower potency than the other antagonists. Taken together, these findings do not support the hypothesis that DA activates a specific population of prejunctional dopaminoceptors to inhibit the motor response elicited by field stimulation in the presence of cocaine, hydrocortisone and 1-propranolol in the prostatic portion of the rat vas deferens. Instead, the population of prejunctional alpha 2-adrenoceptor may be involved.

Analysis of left ventricular function by radionuclide ventriculogram in hypertensive patients treated with atenolol

The myocardial effects of a daily oral dose of atenolol were studied by radionuclide multitriggered ventriculogram in 10 patients (7 men and 3 women) with mild to moderate essential hypertension, aged 29 to 53 years (mean 43) at rest and during exercise. Before and after two months of treatment with 100 mg/day orally of atenolol, the following variables were recordedÑ systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), ejection fraction (EF), peak filling rate (PFR) and peak ejection rate (PER). Beta-blockade treatment caused a significant drop in SBP and DBP, both at rest and during exerciseñ HR slowed down at rest and during exercise. PFR diminished at rest and during exercise. PER was reduced at rest and during exercise (p < 0.001). No significant changes in EF were observed after treatment with atenolol. In conclusion,k atenolol impaired left ventricular relaxation in spite of the drop in blood pressure

Analysis of left ventricular function by radionuclide ventriculogram in hypertensive patients treated with atenolol.

The myocardial effects of a daily oral dose of atenolol were studied by radionuclide multi-triggered ventriculogram in 10 patients (7 men and 3 women) with mild to moderate essential hypertension, aged 29 to 53 years (mean 43) at rest and during exercise. Before and after two months of treatment with 100 mg/day orally of atenolol, the following variables were recorded: systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), ejection fraction (EF), peak filling rate (PFR) and peak ejection rate (PER). Beta-blockade treatment caused a significant drop in SBP and DBP, both at rest and during exercise; HR slowed down at rest and during exercise. PFR diminished at rest and during exercise. PER was reduced at rest and during exercise (p less than 0.001). No significant changes in EF were observed after treatment with atenolol. In conclusion, atenolol impaired left ventricular relaxation in spite of the drop in blood pressure.

Early abnormalities of left ventricular function in essential hypertension induced by exercise.

In order to assess their ventricular function at rest and during exercise, 42 essential hypertensives (164 +/- 2/98.7 +/- 2 mmHg) and 12 normotensives (131.7 +/- 4/81.2 +/- 1 mmHg) were studied. Ejection fraction (EF), peak filling rate (PFR) and peak ejection rate (PER) were measured by means of gated radionuclide ventriculography. At rest, no differences in EF, PFR and PER between hypertensives and normotensives were found. During exercise, hypertensives showed lower PFR (5.3 +/- 0.2 EDV/s) and EF (67.7 +/- 1

) than normotensives (PFR 7 +/- 0.5 EDV/s, p < 0.005 and EF 79.4 +/- 2

, p < 0.001). Likewise, hypertensive showed a lower increase from rest to exercise in PFR and in EF than normotensives p < 0.001. In addition, hypertensives showed a great individual variability in EF response to exercise, where 23 patients increased EF more than 5

and 19 patients failed to increase it during stress. Moreover, the last group of patients had higher systolic blood pressure (SBP) both at rest and during exercise than patients who increased EF, p < 0.01. In addition, there was a significantly negative correlation between resting SBP and the variation of Ef (r = 0.47 y: 163.1-0.79X, p < 0.01). Left ventricular mass (LVM) was similar in the two groups of hypertensives. On the other hand, there were no differences in any of the variables analyzed between the hypertensives with LV hypertrophy and those with normal LVM. These findings suggest that abnormalities in both systolic and diastolic LV during exercise may be found in hypertensive patients even before myocardial hypertrophy can be detected.

Analysis of left ventricular function by radionuclide ventriculogram in hypertensive patients treated with atenolol

The myocardial effects of a daily oral dose of atenolol were studied by radionuclide multitriggered ventriculogram in 10 patients (7 men and 3 women) with mild to moderate essential hypertension, aged 29 to 53 years (mean 43) at rest and during exercise. Before and after two months of treatment with 100 mg/day orally of atenolol, the following variables were recordedÑ systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), ejection fraction (EF), peak filling rate (PFR) and peak ejection rate (PER). Beta-blockade treatment caused a significant drop in SBP and DBP, both at rest and during exerciseñ HR slowed down at rest and during exercise. PFR diminished at rest and during exercise. PER was reduced at rest and during exercise (p < 0.001). No significant changes in EF were observed after treatment with atenolol. In conclusion,k atenolol impaired left ventricular relaxation in spite of the drop in blood pressure (AU)

Early abnormalities of left ventricular function in essential hypertension induced by exercise

In order to assess their ventricular function at rest and during exercise, 42 essential hypertensives (164 +/- 2/98.7 +/- 2 mmHg) and 12 normotensives (131.7 +/- 4/81.2 +/- 1 mmHg) were studied. Ejection fraction (EF), peak filling rate (PFR) and peak ejection rate (PER) were measured by means of gated radionuclide ventriculography. At rest, no differences in EF, PFR and PER between hypertensives and normotensives were found. During exercise, hypertensives showed lower PFR (5.3 +/- 0.2 EDV/s) and EF (67.7 +/- 1%) than normotensives (PFR 7 +/- 0.5 EDV/s, p < 0.005 and EF 79.4 +/- 2%, p < 0.001). Likewise, hypertensive showed a lower increase from rest to exercise in PFR and in EF than normotensives p < 0.001. In addition, hypertensives showed a great individual variability in EF response to exercise, where 23 patients increased EF more than 5% and 19 patients failed to increase it during stress. Moreover, the last group of patients had higher systolic blood pressure (SBP) both at rest and during exercise than patients who increased EF, p < 0.01. In addition, there was a significantly negative correlation between resting SBP and the variation of Ef (r = 0.47 y: 163.1-0.79X, p < 0.01). Left ventricular mass (LVM) was similar in the two groups of hypertensives. On the other hand, there were no differences in any of the variables analyzed between the hypertensives with LV hypertrophy and those with normal LVM. These findings suggest that abnormalities in both systolic and diastolic LV during exercise may be found in hypertensive patients even before myocardial hypertrophy can be detected (Au)

Early abnormalities of left ventricular function in essential hypertension induced by exercise.

In order to assess their ventricular function at rest and during exercise, 42 essential hypertensives (164 +/- 2/98.7 +/- 2 mmHg) and 12 normotensives (131.7 +/- 4/81.2 +/- 1 mmHg) were studied. Ejection fraction (EF), peak filling rate (PFR) and peak ejection rate (PER) were measured by means of gated radionuclide ventriculography. At rest, no differences in EF, PFR and PER between hypertensives and normotensives were found. During exercise, hypertensives showed lower PFR (5.3 +/- 0.2 EDV/s) and EF (67.7 +/- 1

) than normotensives (PFR 7 +/- 0.5 EDV/s, p < 0.005 and EF 79.4 +/- 2

, p < 0.001). Likewise, hypertensive showed a lower increase from rest to exercise in PFR and in EF than normotensives p < 0.001. In addition, hypertensives showed a great individual variability in EF response to exercise, where 23 patients increased EF more than 5

and 19 patients failed to increase it during stress. Moreover, the last group of patients had higher systolic blood pressure (SBP) both at rest and during exercise than patients who increased EF, p < 0.01. In addition, there was a significantly negative correlation between resting SBP and the variation of Ef (r = 0.47 y: 163.1-0.79X, p < 0.01). Left ventricular mass (LVM) was similar in the two groups of hypertensives. On the other hand, there were no differences in any of the variables analyzed between the hypertensives with LV hypertrophy and those with normal LVM. These findings suggest that abnormalities in both systolic and diastolic LV during exercise may be found in hypertensive patients even before myocardial hypertrophy can be detected.

Ambulatory blood pressure monitoring and diastolic left ventricular abnormalities in established and borderline hypertension.

In order to evaluate left ventricular diastolic function by means of Doppler echocardiography in borderline and established hypertension, identified by office and ABPM, compared with normotensives, 54 subjects: 15 normotensives, 11 borderlines and 28 nontreated mild to moderate essential hypertensives were studied. Age and weight were similar among groups. Established hypertensives showed higher left ventricular mass index (p < 0.05), peak velocity of late left ventricular filling (peak A; p < 0.01), ratio peak A/peak velocity of early ventricular filling, peak E (p < 0.01), velocity time integral of systolic atrial volume (p < 0.001), deceleration half time of peak early diastolic inflow velocity (p < 0.05), left ventricular isovolumic relaxation period (IRP; p < 0.01) than normotensives and lower Doppler indexes of early diastolic left ventricular filling (p < 0.01), peak filling rat normalized to mitral stroke volume (PFRn; p < 0.01) than normotensives. Although borderline hypertensives showed intermediate LVM and Doppler indexes between hypertensives and normotensives only IRP (p < 0.05) and PFRn (p < 0.05) were significant different to normotensives. In conclusion, established hypertension leads to abnormalities in left ventricular diastolic function which can be detected by Doppler echocardiography. In borderline hypertension, the left ventricular diastolic abnormalities are predominantly related to the active process of early diastole. Therefore, these indexes may be early markers of left ventricular dysfunction in hypertension.

Early abnormalities of left ventricular function in essential hypertension induced by exercise

In order to assess their ventricular function at rest and during exercise, 42 essential hypertensives (164 +/- 2/98.7 +/- 2 mmHg) and 12 normotensives (131.7 +/- 4/81.2 +/- 1 mmHg) were studied. Ejection fraction (EF), peak filling rate (PFR) and peak ejection rate (PER) were measured by means of gated radionuclide ventriculography. At rest, no differences in EF, PFR and PER between hypertensives and normotensives were found. During exercise, hypertensives showed lower PFR (5.3 +/- 0.2 EDV/s) and EF (67.7 +/- 1%) than normotensives (PFR 7 +/- 0.5 EDV/s, p < 0.005 and EF 79.4 +/- 2%, p < 0.001). Likewise, hypertensive showed a lower increase from rest to exercise in PFR and in EF than normotensives p < 0.001. In addition, hypertensives showed a great individual variability in EF response to exercise, where 23 patients increased EF more than 5% and 19 patients failed to increase it during stress. Moreover, the last group of patients had higher systolic blood pressure (SBP) both at rest and during exercise than patients who increased EF, p < 0.01. In addition, there was a significantly negative correlation between resting SBP and the variation of Ef (r = 0.47 y: 163.1-0.79X, p < 0.01). Left ventricular mass (LVM) was similar in the two groups of hypertensives. On the other hand, there were no differences in any of the variables analyzed between the hypertensives with LV hypertrophy and those with normal LVM. These findings suggest that abnormalities in both systolic and diastolic LV during exercise may be found in hypertensive patients even before myocardial hypertrophy can be detected

Ambulatory blood pressure monitoring and diastolic left ventricular abnormalities in established and borderline hypertension

In order to evaluate left ventricular diastolic function by means of Doppler echocardiography in borderline and established hypertension, identified by office and ABPM, compared with normotensives, 54 subjects: 15 normotensives, 11 borderlines and 28 nontreated mild to moderate essential hypertensives were studied. Age and weight were similar among groups. Established hypertensives showed higher left ventricular mass index (p < 0.05), peak velocity of late left ventricular filling (peak A; p < 0.01), ratio peak A/peak velocity of early ventricular filling, peak E (p < 0.01), velocity time integral of systolic atrial volume (p < 0.001), deceleration half time of peak early diastolic inflow velocity (p < 0.05), left ventricular isovolumic relaxation period (IRP; p < 0.01) than normotensives and lower Doppler indexes of early diastolic left ventricular filling (p < 0.01), peak filling rat normalized to mitral stroke volume (PFRn; p < 0.01) than normotensives. Although borderline hypertensives showed intermediate LVM and Doppler indexes between hypertensives and normotensives only IRP (p < 0.05) and PFRn (p < 0.05) were significant different to normotensives. In conclusion, established hypertension leads to abnormalities in left ventricular diastolic function which can be detected by Doppler echocardiography. In borderline hypertension, the left ventricular diastolic abnormalities are predominantly related to the active process of early diastole. Therefore, these indexes may be early markers of left ventricular dysfunction in hypertension.

Ambulatory blood pressure monitoring and diastolic left ventricular abnormalities in established and borderline hypertension

In order to evaluate left ventricular diastolic function by means of Doppler echocardiography in borderline and established hypertension, identified by office and ABPM, compared with normotensives, 54 subjects: 15 normotensives, 11 borderlines and 28 nontreated mild to moderate essential hypertensives were studied. Age and weight were similar among groups. Established hypertensives showed higher left ventricular mass index (p < 0.05), peak velocity of late left ventricular filling (peak A; p < 0.01), ratio peak A/peak velocity of early ventricular filling, peak E (p < 0.01), velocity time integral of systolic atrial volume (p < 0.001), deceleration half time of peak early diastolic inflow velocity (p < 0.05), left ventricular isovolumic relaxation period (IRP; p < 0.01) than normotensives and lower Doppler indexes of early diastolic left ventricular filling (p < 0.01), peak filling rat normalized to mitral stroke volume (PFRn; p < 0.01) than normotensives. Although borderline hypertensives showed intermediate LVM and Doppler indexes between hypertensives and normotensives only IRP (p < 0.05) and PFRn (p < 0.05) were significant different to normotensives. In conclusion, established hypertension leads to abnormalities in left ventricular diastolic function which can be detected by Doppler echocardiography. In borderline hypertension, the left ventricular diastolic abnormalities are predominantly related to the active process of early diastole. Therefore, these indexes may be early markers of left ventricular dysfunction in hypertension.(Au)