Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of propranolol on serum levels of total and free thyroxine, total and free triiodothyronine, and thyroid-stimulating hormone (TSH) was investigated in 15 clinical euthyroid patients with essential hypertension. Oral propranolol in dosages from 80 to 480 mg/day for a 30-day period induced an average increase in total serum thyroxine of 15.5 +/- 2.2% (mean +/- SEM, 2 p = 0.00002) and in free thyroxine of 17.7 +/- 3.5% (2 p = 0.00009). The oral dose of propranolol correlated positively with serum propranolol (r = 0.70, 2 p = 0.007). No significant correlation between serum propranolol and changes in serum thyroxine could be demonstrated. Total and free triiodothyronine, as well as TSH, remained unchanged during propranolol treatment. The most likely explanation is a propranolol-induced decreased degradation of thyroxine. A practical consequence is that in patients with an uncertain clinical picture and slightly elevated serum thyroxine, propranolol intake should be considered.
 ...
PMID:Propranolol-induced increments in total and free serum thyroxine in patients with essential hypertension. 92 81

A study, using non-invasive techniques, was carried out in ten patients with essential hypertension to examine the mechanism of the hypotensive effect of propranolol when used in combination with a potent vasodilator antihypertensive - minoxidil. The hypotensive effect of minoxidil, a mean (+/- SEM) decrease of 42.4 +/- 4.3 mm Hg, was accompanied by a marked increase in heart rate, cardiac index and plasma renin activity and a significant decrease in total peripheral resistance, limb vascular resistance and pre-ejection period. Addition of propranolol further reduced mean arterial pressure by an average of 12.9 +/- 2.0 mm Hg. Propranolol returned cardiac index to control values and total peripheral resistance index rose but not to control levels. Plasma renin activity was significantly reduced by propranolol. By multiple regression analysis no correlation was found between propranolol-induced decrease in mean arterial pressure and changes in cardiac index, total peripheral resistance index or plasma renin activity. Quantitatively, the reduction in cardiac index observed probably accounted for the hypotensive effect of propranolol. The role of plasma renin activity reduction in the hypotensive effect of propranolol in this situation remains to be clarified. The findings in the present study were consonant with the known actions of vasodilator antihypertensive agents and propranolol and indicate the applicability of non-invasive methodology to the investigation of cardiovascular drugs in man.
 ...
PMID:Mechanism of the interaction of propranolol and a potent vasodilator antihypertensive agent - minoxidil. 97

15 patients (4 females, 11 males, 21 to 55-year old) with mild to moderate essential hypertension (EH) were treated with placebo for two weeks and thereafter with increasing doses of prindolol (15 to 38 mg/day in the mean) and kept on a mean maintenance dosage of 32 mg/day for an average of 16 weeks in all. Blood pressure (BP), heart rate und plasma noradrenaline (PNA) concentrations were measured under standardized conditions (supine, standing, walking) at the end of two weeks on placebo and after the experimental treatment period. The results were compared to those of a group of 15 normotensive untreated control subjects (NS): after an average of 16 weeks on prindolol BP fell from 163/113 mm Hg to 129/91 mm Hg in the mean. PNA levels in EH before prindolol were significantly higher than in NS (supine: 272 +/- 22.0 ng/l (mean +/- SEM) vs. 135 +/- 15.1 ng/l, standing: 448 +/- 31.9 ng/l vs. 359 +/- 18.4 ng/l, walking: 388 +/- 22.5 ng/l vs. 234 +/- 22.1 ng/l). In EH chronic administration of prindolol led to a significant decrease in PNA concentrations under all the three test conditions to levels which did not differ significantly any more from those derived from NS. The adrenergic response to upright posture reflected in the percentage increase in PNA was significantly less in EH before prindolol when compared to the percentage increase in NS. On prindolol the adrenergic response was not abolidhed, yet it tended to approach the values found in NS. Before prindolol under resting conditions diastolic BP correlated closely with the corresponding PNA levels (p less than 0.01, r = 0.66, n = 15). This correlation could not be reestablished after prindolol treatment. The decrease in PNA after long-term treatment with prindolol was not correlated to the fall in blood pressure. The decrease in PNA indicates a lower activity of the sympathetic nervous system which may contribute to the antihypertensive effect of prindolol.
 ...
PMID:Decrease in plasma noradrenaline levels following long-term treatment with prindolol in patients with essential hypertension. 100 67

1. Serum dopamine beta-hydroxylase activity was determined in normotensive control subjects and patients with labile or established essential hypertension. The enzyme activity was 25-9 +/- 1-9 (SEM) 29-6 +/- 2-5 and 25-1 +/- 1-9 micronmol min-1 1-1, for control, labile and established hypertensive subjects respectively. 2. Neither blood pressure nor serum dopamine beta-hydroxylase activity was changed in normotensive control subjects by administration of phentolamine; however, in patients with essential hypertension blood pressure was significantly decreased (P is less than 0-01) and serum dopamine beta-hydroxylase activity was slightly increased. With propranolol administration, blood pressure and the serum enzyme activity were not significantly changed in normotensive or hypertensive subjects. 3. Our results suggest that there is no correlation between serum dopamine beta-hydroxylase activity and blood pressure.
 ...
PMID:Serum dopamine beta-hydroxylase activity in essential hypertension. 107 65

To study limb vascular responses in man to elevations in plasma calcium concentrations, we infused test isosmolar solutions of CaCl2 (0.115, 0.230, and 0.460 meq calcium/min) and NaCl and control isosmolar solutions of NaCl into the brachial arteries of 10 normotensive men and eight men with essential hypertension of mild to moderate severity. Limb blood pressures were monitored, limb blood flow was measured by indicator-dilution, and limb vascular resistance was calculated as mm Hg/ml flow/min/100 cm3 limb volume. Measured concentration of calcium in limb venous plasma during infusion of 0.460 meq calcium/min was 11.5 +/- 0.8 meq/liter (mean +/- SEM) with individual values ranging up to 20 meq/liter. Changes in limb venous serum sodium, potassium, magnesium, and osmolality were similar during control and CaCl2 infusions. Decreases in limb venous blood hematocrit during CaCl2 infusions were the same or greater than those during control infusions. The infusions did not significantly change systemic blood calcium concentration or blood pressures. Limb blood flow decreased and resistance increased in response to CaCl2. Increments averaging as little as 2.2 meq/liter elevated limb resistance by about 45%. Log dose-response curves were linear. Responses did not differ in normotensives and hypertensives (P greater than 0.8). We conclude that the vascular response to acute elevation of plasma calcium concentrations up to 20 meq/liter in the limb oman is an impressive vasoconstriction. We found no evidence for abnormal vascular responses to calcium in essential hypertensive men.
 ...
PMID:Similar vasoconstrictor responses to calcium in normotensive and esssential hypertensive men. 109 55

A study was made of the possible mechanism(s) underlying minoxidil-induced increase in plasma renin activity (PRA). 10 patients with essential hypertension were treated with minoxidil and subsequently with a combination of minoxidil plus propranolol. Minoxidil lowered mean arterial pressure 31.6 plus or minus 3.3 mm Hg, mean plus or minus SEM. There was an associated increase in both PRA, 6.26 plus or minus 2.43 NG/ML/H, and heart rate, 21.4 plus or minus 2.7 beats/min. The changes in PRA and heart rate were positively correlated, r, 0.79. Addition of propranolol reduced mean arterial pressure by a further 10.1 plus or minus 1.5 mm Hg and returned heart rate to control levels. Propranolol reduced PRA significantly but not to control levels. Control PRA positively correlated with PRA on minoxidil, r, 0.97, and with PRA on minoxidil plus propranolol, r, 0.98. We conclude that control PRA is a major determinant of change in PRA with minoxidil. Minoxidil increased PRA by at least two mechanisms: (a) an adrenergic mechanism closely related to change in heart rate and blocked by propranolol, and (b) a mechanism(s) not sensitive to propranolol and possibly related to decrease in renal perfusion pressure.
 ...
PMID:Control plasma renin activity and changes in sympathetic tone as determinants of minoxidil-induced increase in plasma renin activity. 112 99

In 19 control subjects, 33 patients with essential hypertension and normal plasma renin activity (PRA) and 11 patients with low PRA, secretory rates of 18-hydroxy-11-deoxy-corticosterone (18-OH DOC), 11-deoxycorticosterone (DOC) and corticosterone were measured. Patients with low PRA were significantly older and had higher arterial pressure and slightly lower plasma potassium levels than patients with normal PRA. Mean 18-OH DOC secretion rate was higher in patients with normal PRA (603 +/- 112 SEM mug/24 hr) than in control subjects (219 +/- 19) and considerably higher (P less than 0.001) in patients with low PRA (1800 +/- 472). DOC and corticosterone secretion rates were within normal limits in most hypertensive patients. Plasma aldosterone was significantly higher in the hypertensive population than in control subjects whereas no significant difference was observed between the low- and normal-renin groups. A significant (P less than 0.01) mutual positive correlation was found between the secretion rates of 18-OH DOC, DOC and corticosterone in patients with low plasma renin activity. In contrast, there was no correlation between the secretion rates of the three mineralocorticoids in control subjects and patients with normal plasma renin activity. These data suggest a biosynthetic variation of the mineralocorticoid pathways in essential hypertension.
 ...
PMID:Mineralocorticoid secretion in essential hypertension with normal and low plasma renin activity. 124 73

We assessed the long-term effects of carvedilol on renal function in 10 patients with mild-to-moderate essential hypertension. After a 2- to 4-week placebo run-in period, all patients received 5 mg carvedilol once daily. If the effect was insufficient, the dosage was successively increased to 10 or 20 mg once daily. The mean +/- SEM duration of treatment was 17.3 +/- 1.0 weeks, and the final mean daily dosage was 13.5 +/- 2.2 mg/day. With treatment, systolic and diastolic blood pressures decreased significantly from 159.7 +/- 1.3 to 140.5 +/- 3.2 mm Hg (p less than 0.001) and from 98.3 +/- 1.0 to 88.2 +/- 2.7 mm Hg (p less than 0.001), respectively. Carvedilol did not cause significant changes in glomerular filtration rate, effective renal plasma flow, blood urea nitrogen, or serum creatinine. Renal vascular resistance decreased significantly from 12.7 +/- 1.4 to 11.2 +/- 1.2 dyne.s.cm-5/1.48 m2 x 10(3) (p less than 0.05). Thus, long-term carvedilol therapy was effective in reducing blood pressure in essential hypertension without causing impairment of renal function.
 ...
PMID:Effect of long-term carvedilol therapy on renal function in essential hypertension. 137 58

Adrenaline was infused in incremental doses of 0.05 up to 0.1 microgram/kg/min over a 60-min period in nine patients with mild essential hypertension and six age-matched normotensive controls. Blood samples were drawn at preset time intervals and plasma adrenaline, platelet count, serum thromboxane B2 (TxB2) and plasma beta-thromboglobulin (beta-TG) were measured. Adrenaline levels (m +/- SEM) rose significantly, from 0.078 +/- 0.01 (baseline) to 0.902 +/- 0.03 ng/ml (60 min), in the hypertensive group; a similar increase was observed in the control group (from 0.049 +/- 0.007 to 0.877 +/- 0.03 ng/ml). Platelet count increased significantly at early time points and remained high throughout infusion in both groups (hypertensive from 250 +/- 25 to 305 +/- 24 x 10(3)/microliters, control from 219 +/- 16 to 260 +/- 18 x 10(3)/microliters). TxB2 levels likewise increased significantly from 15 minutes after initiation of infusion. In hypertensive subjects the mean resting value of 186 +/- 17 ng/ml rose to 312 +/- 42 ng/ml, while in control subjects the resting value of 174 +/- 29 ng/ml rose to 286 +/- 32 ng/ml. Baseline levels of TxB2 were found to be higher in the hypertensive patients but not significantly. beta-TG levels increased from an initial value of 43.84 +/- 3.69 ng/ml to 59.5 +/- 4.69 ng/ml at 60 min in the hypertensive group, while a similar change from 28.7 +/- 19.2 ng/ml to 40.36 +/- 3.16 ng/ml was observed in the control group. These changes were significant, as was the difference between basal values in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Effects of adrenaline infusion on serum thromboxane B2 and plasma beta-thromboglobulin levels in hypertensive and normotensive subjects. 138 33

In elderly hypertensive patients effect of antihypertensive treatment with Ca antagonist or ACE inhibitor on the heart were examined. Twenty-four elderly hypertensive patients with cardiac hypertrophy, aged 65-79 years old (mean +/- SEM, 71 +/- 1) were treated with Ca antagonist (nifedipine or nicardipine) or ACE inhibitor (captopril or enalapril) for 3 months. Thirteen patients had essential hypertension (EH: SBP greater than or equal to 160 mmHg and DBP greater than or equal to 95 mmHg, 70 +/- 1 years) and 11 had isolated systolic hypertension (ISH: SBP greater than or equal to 160 mmHg and DBP less than 95 mmHg, 74 +/- 2 years). Blood pressure (BP) and heart rate were measured every two weeks. In all patients, M-mode echocardiography was performed to measure left ventricular mass index (LVMI) and ejection fraction (EF), and the sympathetic nervous (plasma norepinephrine and epinephrine) and the renin-angiotensin system (plasma renin activity and aldosterone concentration), were assessed before and after 3 months of treatment. BP significantly decreased from 174 +/- 3/97 +/- 1 to 149 +/- 4/84 +/- 2 mmHg in EH and from 167 +/- 3/82 +/- 2 to 144 +/- 4/74 +/- 2 mmHg in ISH. LVMI was significantly reduced from 204 +/- 14 to 174 +/- 16 g/m2 in EH and from 179 +/- 14 to 156 +/- 12 g/m2 in ISH. EF showed no significant changes in either group. In ISH, the change in LVMI was significantly correlated with the change in systolic BP (r = 0.74, p less than 0.05). In EH, there was no significant relation between BP and LVMI changes.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Effect of antihypertensive treatment in elderly hypertensive patients with cardiac hypertrophy]. 138 12


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>