Chromaffin granule ghosts from bovine adrenal medullae have been used to examine the ability of membrane-bound dopamine beta-monooxygenase to interact directly with intravesicular ascorbate and to investigate vectorial electron transfer from external ascorbate across the ghost membrane. Ghosts prepared by a modification of published procedures were shown to be fully active in both dopamine upta...

OBJECTIVE The authors examined whether patients with attention deficit hyperactivity disorder (ADHD) have altered striatal dopamine transporter levels, which may explain psychostimulant effects in this disorder. METHOD Single photon emission computed tomography and [(123)I]2beta-carbomethoxy-3beta-(4-iodophenyl)tropane ([(123)I]beta-CIT) were used to assess dopamine transporter availability i...

Thyrotropin (TSH) is an anterior pituitary glycoprotein hormone which modulates thyroid hormone production by the thyroid gland. TSH and its two subunits, TSH beta and alpha-subunit, are in turn regulated by the thyroid hormones and several stimulatory and inhibitory factors produced by the hypothalamus. Hypothalamic hormones such as thyrotropin-releasing hormone (TRH) and dopamine have profoun...

Dopamine beta-hydroxylase exists in bovine adrenal medulla chromaffin granules in both soluble and membrane-bound forms. The mechanism by which membranous dopamine beta-hydroxylase is bound to granule membranes has been elusive. Recently, evidence that covalently attached phosphatidylinositol does not serve as an anchor for membranous dopamine beta-hydroxylase was reported (Stewart, L. C., and ...

Ascorbic acid enhancement of norepinephrine formation from tyrosine in cultured bovine chromaffin cells was characterized in detail as a model system for determining ascorbate requirements. In resting cells, ascorbic acid increased dopamine beta-monooxygenase activity without changing tyrosine 3-monooxygenase activity. [14C]Norepinephrine specific activity was increased by ascorbic acid, while ...

Dopamine beta-hydroxylase was present as 2 subunit forms (apparent Mr = 77,000 and 73,000) in the PC12 pheochromocytoma cell line as detected by immunoprecipitation from [35S]methionine-labeled cultures, and analyzed by sodium dodecyl sulfate gel electrophoresis and fluorography. The Mr = 77,000 form was present in a crude membrane fraction, while the Mr = 73,000 form was soluble. Both forms ap...

Synchronised neuronal oscillations at beta frequencies are prevalent in the human motor system, but their function is unclear. In this Opinion article, we propose that the levels of beta oscillations provide a measure of the likelihood that a new voluntary action will need to be actuated. Oscillatory beta activity is in turn modulated by net dopamine levels at sites of cortical input to the bas...

Parkinson’s disease (PD) is a progressive neurodegenerative that characterized by the loss of dopamine. Since dopamine has trouble entering blood–brain barrier, utilization dendrimers and other nanomaterials considered for conjugating neurotransmitter PD drugs. Dendrimers are three-dimensional, hyper-branched structures categorized into several generations. Alpha-synuclein (ASN) protein involve...