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

The concentrations of unconjugated plasma dopamine (PDA) were studied in patients with various types of hypertension. Catecholamines were extracted from plasma specimens (1.0-3.0 ml) through an Amberlite CG50 (Li+-form) microcolumn and eluted by a magnesium sulfate - ethanol solution. The elute was then desalinated and deproteinized by the ethanol-treated precipitation procedure and dried in a vacuum oven at 25 degrees C. A fraction of catecholamines was assayed with the modified procedures of the COMT-mediated radio-enzymatic method. This assay system was sensitive enough to permit an accurate measurement of PDA as low as 6.0 pg per ml of plasma without any detectable contamination of the conjugated dopamine. The resting levels of PDA were 10.1 +/- 1.0 pg/ml (mean +/- SEM), 9.5 +/- 1.0 and 13.7 +/- 0.6 in patients with borderline hypertension (BH, n = 25), essential hypertension (EH, n = 22) and renovascular hypertension (RVH, n = 8), respectively. The values in EH patients were significantly smaller than those in age-matched normal controls (13.0 +/- 1.4, n = 14, p less than 0.05). Remarkably increased PDA values were observed in patients with pheochromocytoma (76.5 +/- 25.4, n = 9, p less than 0.01). Significantly raised PDA values were also found in patients with primary aldosteronism (PA, 27.8 +/- 9.0, n = 6, p less than 0.05), while their plasma norepinephrine levels (PNE, 169 +/- 39 pg/ml) tended to be lower than those of normal controls (206 +/- 20), showing an apparent dissociation between the values of PDA and PNE. Upright posture for 15 minutes induced a significant rise in PDA (p less than 0.05) in all subjects except PA patients. The postural changes of PDA, however, were invariably smaller than those of PNE (p less than 0.05). The resting values of PDA in normal, BH and EH patients showed a significant negative correlation with their mean arterial pressures (r = -0.301, n = 61, p less than 0.05) and a positive correlation with those of PNE (r = 0.381, p less than 0.01). There was no correlation between PDA and age in any group studied. These findings indicate that PDA might not be only a precursor fraction of neurotransmitters released from the sympathetic nervous system but could also represent a physiological function of the dopaminergic regulatory system. The varied but distinctive features of PDA status in various types of hypertension suggest the possibility that the peripheral dopaminergic mechanisms play an inherent role in the pathogenesis of hypertension.
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PMID:[Plasma dopamine concentrations in various types of hypertension]. 375 30

Plasma renin activity (PRA), plasma aldosterone (PA) and plasma catecholamines were measured in 3 groups of women with pregnancy of 20-38 weeks: group I of 16 normotensive controls, group II of 17 women with rest responding hypertension (RRH) and group III of 18 women with permanent hypertension (PH) (supine blood pressure greater than 140-90 mmHg after 8 days of rest, disappearing after delivery). Studies were realized on fasting ambulatory women on a normal salt diet. PRA (mean +/- SEM) was significantly higher in the RRH group than in the control and PH groups (15,8 +/- 2,3 ng/ml/h versus 6,7 +/- 0,5 and 8,9 +/- 0,9). PA was higher but not significantly in the RRH group (736 +/- 122 versus 533 +/- 52 and 502 +/- 103 pg/ml). Plasma epinephrine (PE) and norepinephrine (PNE) were significantly higher in the PH than in the control and RRH groups. 135 +/- 28 pg/nl versus 56 +/- 13 and 63 +/- 17 for PE and 387 +/- 91 versus 206 +/- 32 and 200 +/- 47 pg/ml). These data suggest that PH is linked with activation of the adrenergic system whereas RRH is linked with activation of the RAA system.
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PMID:[The renin-angiotensin-aldosterone system and the adrenergic system in normal pregnancy and hypertension induced by pregnancy]. 681 Aug 37

Sympathetic nervous system may play an important role in the pathogenesis of essential hypertension. The present study was undertaken to evaluate the interaction between sodium intake and sympathetic nervous activity in the patients with essential hypertension. Plasma and urinary catecholamines (CA) were measured in 38 hypertensive patients (WHO 1-2 stage) and 24 age-matched normal subjects on regular (urinary sodium excretion (UNaV): 133 +/- 8 mEq/day; mean +/- SEM), high (UNaV 317 +/- 90 mEq/day), and low (UNaV 67 +/- 28 mEq/day) sodium diets for each 5 days at random. CA were analyzed by THI methods after HPLC separation. Twenty-four hour urinary norepinephrine (NE), epinephrine (E), and electrolytes (Na+, K+) excretion on the 5th day of each regimen were determined. In the 6th day morning supine and 5 min upright plasma NE(PNE), plasma E (PE), and plasma renin activity were determined after blood pressure and pulse rate measurement. The results were also analyzed according to the difference between salt-sensitive and non-salt-sensitive type of hypertensive patients. Plasma NE was 1.1 +/- 0.4 p mol/ml (supine), 1.5 +/- 0.4 p mol/ml (upright) in normotensive subjects and 1.8 +/- 1.1 p mol/ml (supine), 2.5 +/- 1.1 p mol/ml (upright) in the patients with essential hypertension, 24 hr urinary NE excretion were 116 +/- 54 micrograms/day in normotensive subjects and 138 +/- 88 micrograms/day in the patients with essential hypertension on regular sodium intake. Mean plasma NE levels in patients with essential hypertension were always higher than those in normotensive subjects on any sodium diets. Plasma NE and urinary NE were significantly reduced by high sodium intake and increased by low sodium intake in both normotensive subjects and the patients with essential hypertension. Percentile decrease in PNE when the diet was changed from low sodium to high sodium was much greater in normotensive subjects than the patients with essential hypertension. These tendency was observed in both salt-sensitive and non-salt-sensitive hypertensive patients. However, PNE in non-salt-sensitive hypertensive subjects tended to be higher than those in salt-sensitive hypertensive subjects. These results suggest that abnormal relationship between sodium intake and sympathetic nervous system may play an important role in the pathogenesis of essential hypertension.
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PMID:[Plasma norepinephrine variation with dietary sodium intake in normotensive subjects and patients with essential hypertension]. 717 54