Track topics on Twitter Track topics that are important to you
In addition to exerting actions via mineralocorticoid and glucocorticoid receptors, corticosteroids also act by inhibiting uptake(2), a high-capacity monoamine transport system originally described in peripheral tissues. Recent studies have demonstrated that uptake(2) transporters are expressed in the brain and play roles in monoamine clearance, suggesting that they mediate some corticosteroid effects on physiological and behavioral processes. However, the sensitivity of brain uptake(2) to many natural and synthetic corticosteroids has not been characterized. Cultured rat cerebellar granule neurons (CGNs) were previously shown to exhibit corticosterone-sensitive accumulation of the uptake(2) substrate1-methyl-4-phenylpyridinium (MPP(+)). We examined the expression of uptake(1) and uptake(2) transporters in CGNs, and tested the effects of a variety of natural and synthetic corticosteroids on accumulation of [(3)H]-MPP(+) by these cells. Cultured rat CGNs expressed mRNA for three uptake(2)-like transporters: organic cation transporters 1 and 3, and the plasma membrane monoamine transporter. They did not express mRNA for the dopamine or norepinephrine transporters, and expressed very little mRNA for the serotonin reuptake transporter. Accumulation of [(3)H]-MPP(+) by CGNs was dose-dependently inhibited by corticosterone and decynium-22, known inhibitors of uptake(2). Accumulation of MPP(+) was also dose-dependently inhibited, with varying efficacies, by aldosterone, 11-deoxycorticosterone, cortisol, and cortisone, and by the synthetic glucocorticoids betamethasone, dexamethasone and prednisolone, and the glucocorticoid receptor antagonist RU38486. These studies demonstrate that uptake(2) in the CNS is inhibited by a variety of natural and synthetic corticosteroids, and suggest that inhibition of uptake(2)-mediated monoamine clearance may underlie some behavioral and physiological effects of these hormones.
Marquette University, Department of Biomedical Sciences, Milwaukee, WI 53233, USA.
This article was published in the following journal.
Name: Physiology & behavior
Radiolabeled meta-iodobenzylguanidine (mIBG) is used for imaging and therapy of neuroblastoma as well as pheochromocytoma. However, non-tumorous tissues also incorporate mIBG mainly by organic cation ...
P-glycoprotein (P-gp), a well known efflux transporter in the blood brain barrier inhibits the uptake of substrate drugs into brain. The main aim of this study is to evaluate the effect of natural pro...
Ikarugamycin (IKA) is a previously discovered antibiotic, which has been shown to inhibit the uptake of oxidized low-density lipoproteins in macrophages. Furthermore, several groups have previously us...
Suppression of the reticuloendothelial system (RES) uptake is one of the most challenging tasks in nanomedicine. Coating stratagems using polymers, such as poly(ethylene glycol) (PEG), have led to gre...
Feedback loops in biological networks, among others, enable differentiation and cell cycle progression, and increase robustness in signal transduction. In natural networks, feedback loops are often co...
In this study we hypothesize infusion of Angiotensin II improves the insulin-induced microvascular dilatation and therefore insulin-mediated glucose uptake. Objectives: Does infusion of An...
Leukotriene receptor antagonists (LTRAs) are frequently prescribed to reduce the symptoms associated with asthma. Singulair, manufactured by Merck, is a popular LTRA, however its effectiv...
Adenosine A1 and A2 receptors are widely distributed in the brain and spinal cord and represent a non-opiate target for pain management. Activated spinal A1 receptors inhibit sensory tran...
The purpose of this study is to evaluate the use of the VersaMed iVent ventilator in the acute care setting, hypothesizing that, in comparison to the standard approach, the use of the Vers...
The activity of the sympathetic nervous system seems to influence the uptake (and handling) of glucose by the skeletal muscle of the forearm. Conditions in which sympathetic activity is in...
Drugs that inhibit the transport of neurotransmitters into axon terminals or into storage vesicles within terminals. For many transmitters, uptake determines the time course of transmitter action so inhibiting uptake prolongs the activity of the transmitter. Blocking uptake may also deplete available transmitter stores. Many clinically important drugs are uptake inhibitors although the indirect reactions of the brain rather than the acute block of uptake itself is often responsible for the therapeutic effects.
Drugs that block the transport of DOPAMINE into axon terminals or into storage vesicles within terminals. Most of the ADRENERGIC UPTAKE INHIBITORS also inhibit dopamine uptake.
Compounds that specifically inhibit the reuptake of serotonin in the brain. This increases the serotonin concentration in the synaptic cleft which then activates serotonin receptors to a greater extent. These agents have been used in treatment of depression, panic disorder, obsessive-compulsive behavior, and alcoholism, as analgesics, and to treat obesity and bulimia. Many of the ADRENERGIC UPTAKE INHIBITORS also inhibit serotonin uptake; they are not included here.
A centrally active drug that apparently both blocks serotonin uptake and provokes transport-mediated serotonin release.
Membrane transport proteins found predominately in NEURONS and neuroendocrine cells that facilitate neurotransmitter transport. They include two distinct families of proteins that transport NEUROTRANSMITTERS across the PLASMA MEMBRANE and that transport NEUROTRANSMITTERS into SECRETORY VESICLES.
Neurology - Central Nervous System (CNS)
Alzheimer's Disease Anesthesia Anxiety Disorders Autism Bipolar Disorders Dementia Epilepsy Multiple Sclerosis (MS) Neurology Pain Parkinson's Disease Sleep Disorders Neurology is the branch of me...
Of all the types of Dementia, Alzheimer's disease is the most common, affecting around 465,000 people in the UK. Neurons in the brain die, becuase 'plaques' and 'tangles' (mis-folded proteins) form in the brain. People with Al...