Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0085580 (essential hypertension)
 14,686 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The concentration of plasma catecholamines (CA), serum dopamine beta-hydoxylase (DBH) activity and plasma renin activity (PRA) were simultaneously measured in 55 patients with essential hypertension (EH). Further the enzyme activities of CA biosynthesis in human vas deferens excised at elective vasectomy were related with the blood pressure, plasma CA, serum DBH of 57 men at the time of vasectomy. Total plasma CA and norepinephrine (NE) were increased in 28 and 35% of patients with benign EH, respectively. Total plasma CA were also increased in 45% of men with elevated blood pressure prior to vasectomy. Total plasma CA were correlated with diastolic blood pressure in EH (p less than 0.01). Further, in men with normal and raised blood pressure prior to vasectomy, there was a significant correlation of total plasma CA with systolic and diastolic blood pressure (p less than 0.01). Total plasma CA were correlated with PRA in patients with EH (r=0.497, p less than 0.001). Capacity for NE biosynthesis, vas deferens tyrosine hydroxylase (TYH) activity and dopa decarboxylase (DDC) activity were increased in men with raised blood pressure. There was a direct correlation of total plasma CA with the activities of TYH and DDC (r=0.46, and 0.54, p less than 0.005). Increased sympathetic nerve tonicity associated with increased neurotransmitter biosynthesis may be an important factor responsible for blood pressure elevation in men prior to vasectomy and in others with EH. The some patients with EH may have a renin-catecholamine relationship and both pressor systems may be linked to be a pathogenic factor for the elevation of blood pressure.
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PMID:Biochemical evaluation of sympathetic nerve tone in essential hypertension. 23 60

Aromatic-L-aminoacid (dopa) decarboxylase (ALAAD) was determined in human plasma by its ability to form dopamine from the substrate 3,4-dihydroxyphenylalanine in the presence of pyridoxal-5-phosphate as cofactor. Dopamine formed was quantitated by high performance liquid chromatography with electrochemical detection. A preincubation step of plasma with the cofactor and dithioerythritol was necessary to obtain optimal reaction conditions. The assay method showed good linearity and reproducibility. The inhibition pattern of the therapeutically used peripheral dopa decarboxylase inhibitors, carbidopa and benserazide, was studied and appeared to be dependent on whether the inhibitor was added before or after the preincubation step. Mean levels in 40 control subjects, in 40 patients with essential hypertension and in 15 patients with phaeochromocytoma, were 34.6 (SD 12.1), 28.5 (SD 10.9) and 34.7 (SD 18.4) mU/l respectively. In the patients with essential hypertension the enzyme level decreased with age (p less than 0.05). Very high levels were found in plasma of two patients with metastatic phaeochromocytoma and in two patients with untreated neuroblastoma, but not in two patients with neuroblastoma after chemotherapy. The method described can be used for measuring uninhibited ALAAD activity in patients treated with benserazide, as well as for measuring total, i.e. the sum of inhibited and uninhibited, ALAAD activity in patients treated with carbidopa.
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PMID:Determination of aromatic-L-amino acid decarboxylase in human plasma. 376 7