rifampin and Pheochromocytoma

A validated high performance liquid chromatographic assay for urinary catecholamines is presented. After addition of 3,4-dihydroxybenzylamine as internal standard (IS) to urine, norepinephrine (NE), epinephrine (E), dopamine (DA) are extracted by ion exchange chromatography and eluted with boric acid. After paired ion separation, quantitation is by electrochemical (coulometric) detection after correction of internal standard recovery. Novel interferences by anti-TB drugs on norepinephrine assay are discussed. A simple method for their removal using alumina is presented.

Topics: Aluminum Oxide; Antitubercular Agents; Chromatography, High Pressure Liquid; Dopamine; Epinephrine; False Positive Reactions; Humans; Norepinephrine; Pheochromocytoma; Rifampin; Sensitivity and Specificity

The aggregation and cerebral deposition of amyloid beta protein (A beta), which is a major component of senile plaques in Alzheimer's disease (AD) brains, is believed to be involved in the pathogenesis of AD. Inhibition of A beta aggregation would seem to be a promising strategy for the treatment of AD. Here, we show that rifampicin, which is an antibiotic widely used in the treatment of tuberculosis and leprosy, inhibited the aggregation and fibril formation of synthetic A beta 1-40 peptide in a dose-dependent manner at reasonable concentrations. Furthermore, rifampicin was found to prevent A beta 1-40-induced neurotoxicity on rat pheochromocytoma PC12 cells. Rifampicin may have therapeutic potential as an agent for inhibiting the initial step of amyloid formation in AD.

Topics: Adrenal Gland Neoplasms; Alzheimer Disease; Amyloid beta-Peptides; Animals; Brain; Cell Survival; Dose-Response Relationship, Drug; Humans; Molecular Structure; Neurotoxins; PC12 Cells; Pheochromocytoma; Rats; Rifampin; Rifamycins; Structure-Activity Relationship