Human plasma contains several catechols, including the catecholamines norepinephrine, epinephrine, and dopamine, their precursor, L-3,4-dihydroxyphenylalanine (L-DOPA), and their deaminated metabolites, dihydroxyphenylglycol, the main neuronal metabolite of norepinephrine, and dihydroxyphenylacetic acid, a deaminated metabolite of dopamine. Products of metabolism of catechols include 3-methoxyt...

A 60 year old hypertensive patient suffered several cerebral infarctions. A phaeochromocytoma was suspected because the excretion rates of vanillylmandelic acid and its methoxy derivatives were raised and the patient had hypertensive crises. No tumour was found, however, by 131mI-iodobenzylguanidine scintigraphy and computed tomography of the abdomen. Moreover, the enhanced orthostatic plasma c...

First Admission The patient's blood pressure was found to be 150/ 110 mm Hg, and pelvic exam revealed a large pelvic mass. Intravenous pyelogram showed normal kidneys and collecting system; a pelvic soft tissue mass indented the bladder. Serum potassium was 2.8 mEq/liter, random peripheral plasma renin activity (PRA) was 52 ng angiotensin I (ANG I)/ml/hr (normal upper limit on a low salt diet =...

This article provides an update about catecholamine metabolism, with emphasis on correcting common misconceptions relevant to catecholamine systems in health and disease. Importantly, most metabolism of catecholamines takes place within the same cells where the amines are synthesized. This mainly occurs secondary to leakage of catecholamines from vesicular stores into the cytoplasm. These store...

A three and a half year old male with multifocal phaeochromocytoma involving the right adrenal gland and an intrathoracic mass is presented. Twenty four hour vanillylmandelic acid (VMA) was negative despite suggestive symptomatology. The diagnosis was made on serial CT scans of the head, thoracic inlet and pelvis. He underwent right adrenalectomy and thoracotomy to remove the abdominal and intr...

The effect of exposure to different amounts of polychlorocamphene (toxaphene) on the level of cathecholamines (noradrenalin and adrenalin), their precursors (DOPA and dophamine), and a metabolite (vanillylmandelic acid) in tissues (adrenals, brain, heart) and daily urine in white male rats has been studied. It was established that the single administration of 120 mg/kg toxaphene (half the LD50)...

First Admission The patient's blood pressure was found to be 150/ 110 mm Hg, and pelvic exam revealed a large pelvic mass. Intravenous pyelogram showed normal kidneys and collecting system; a pelvic soft tissue mass indented the bladder. Serum potassium was 2.8 mEq/liter, random peripheral plasma renin activity (PRA) was 52 ng angiotensin I (ANG I)/ml/hr (normal upper limit on a low salt diet =...

A 61 year old hypertensive woman presented in 1986 with a right scapular chondrosarcoma. She developed type 1 diabetes mellitus in 1991 and suffered a stroke in 1991. Chest radiography showed pulmonary metastases in 1997. Further radiological staging detected a right sided phaeochromocytoma, which was subsequently removed in 1998. Before this, repeated urine estimations of vanillylmandelic acid...

A method of separation and determination of homovanillic acid (HVA) and vanillylmandelic acid (VMA) was developed based on capillary zone electrophoresis/amperometric detection with high sensitivity, good resolution and selectivity. In order to achieve complete separation and good response, several factors including pH, buffer concentration, separation voltage, detection potential and the lengt...