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Your search keyword '"Osmotic minipump"' showing total 4 results
Start Over Descriptor "Osmotic minipump" Publisher elsevier
4 results on '"Osmotic minipump"'

1. Effects of acute olanzapine after sustained fluoxetine on extracellular monoamine levels in the rat medial prefrontal cortex

Author

Amargós-Bosch, Mercè, Artigas, Francesc, Adell, Albert, Amargós-Bosch, Mercè, Artigas, Francesc, and Adell, Albert

Abstract

The combination of selective serotonin reuptake inhibitors with atypical antipsychotic drugs exhibits beneficial effects in treatment-resistant depression. We investigated the effects of a 2-week treatment with a low fluoxetine dose (3 mg/kg per day) plus a single injection of olanzapine (3 mg/kg) on the dialysate concentration of noradrenaline, dopamine and serotonin (5-HT) in the medial prefrontal cortex of the rat. Chronic fluoxetine increased only 5-HT levels whereas single olanzapine administration increased the concentration of catecholamines and decreased that of 5-HT to a comparable extent in vehicle- and fluoxetine-treated rats. Therefore, it is possible that the therapeutic benefit of this pharmacological combination may not be associated to changes in the cortical concentration of monoamines, but to postsynaptic blockade of monoaminergic receptors.

Published
2005

2. Using Osmotic Minipumps for Intracranial Delivery of Amino Acids and Peptides

Author

Michael W. Schwartz and Jeffrey D. White

Subjects
chemistry.chemical_classification, Osmotic minipump, chemistry, business.industry, Medicine, Pharmacology, business, CNS tissue, Amino acid
Abstract

Publisher Summary This chapter discusses the usage of osmotic minipumps for intracranial delivery of amino acids and peptides. Osmotic minipump delivery systems can be designed to deliver virtually any compound into the central nervous system (CNS) via indwelling cannulas for administration via the CSF or into specific tissue sites. When used with appropriate care and on recognizing the limitations to conclusions derived from the data obtained, these systems can be used to approach a wide variety of behavioral, physiological, and biochemical questions. This chapter presents the experiences from laboratories and reviews the work in which osmotic minipumps have been used to infuse peptides, amino acids, and drugs through indwelling cannulas into the cerebral ventricles or into specific CNS tissue sites. It focuses on technical considerations for using minipump delivery systems and also highlights potential limitations, pitfalls, and controls to consider when using these systems. The chapter presents examples of studies in which osmotic minipumps have been used to deliver peptides, amino acids, or associated drugs. These examples demonstrate that minipump delivery systems have been used successfully to address numerous neurobiological problems with a variety of agents.

Published
1994
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3. A novel method to induce nicotine dependence by intermittent drug delivery using osmotic minipumps.

Author

Brynildsen JK, Najar J, Hsu LM, Vaupel DB, Lu H, Ross TJ, Yang Y, and Stein EA

Subjects
Mecamylamine administration & dosage, Osmosis, Substance Withdrawal Syndrome, Drug Delivery Systems instrumentation, Tobacco Use Disorder
Abstract

Although osmotic minipumps are a reliable method for inducing nicotine dependence in rodents, continuous nicotine administration does not accurately model the intermittent pattern of nicotine intake in cigarette smokers. Our objectives, therefore, were to investigate whether intermittent nicotine delivery via osmotic minipumps could induce dependence in rats, and to compare the magnitude and duration of withdrawal following forced abstinence from intermittent nicotine to that induced by continuous nicotine administration. In order to administer nicotine intermittently, rats were surgically implanted with saline-filled osmotic minipumps attached to polyethylene tubing that contained hourly unit doses of nicotine alternating with mineral oil to mimic "injections". Three doses of nicotine (1.2, 2.4, and 4.8mg/kg/day) and saline were administered for 14days using this method. In order to compare our intermittent delivery method with the more traditional continuous nicotine delivery, a second group of rats was implanted with minipumps attached to tubing that delivered continuous nicotine for 14days. Rats were administered a 1.5mg/kg subcutaneous (SC) mecamylamine challenge and observed for somatic signs of withdrawal on days 7, 14, 21, and 28 following minipump implantation. Fifteen somatic withdrawal signs were summed within a 50-minute observation period to obtain a composite Dependence Score. A generalized linear mixed-effects model revealed a significant Day×Dose×Method interaction. Amongst continuously-treated rats, only 4.8mg/kg/d nicotine resulted in dependence scores significantly greater than those of controls at 14days of exposure. In contrast, all intermittent nicotine groups showed significantly higher scores beginning at 7days of exposure and persisting beyond 7days of abstinence. In general, intermittent delivery produced a more robust withdrawal syndrome than continuous delivery, and did so at a lower dose threshold and with greater persistence after forced abstinence., (Published by Elsevier Inc.)

Published
2016
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4. Combined use of the chemitrode with osmotic minipumps for experimental brain research

Author

M. Girgis, P Stobo, John E.J. Rasko, S Kohlhardt, and Jennifer Kent

Subjects
Materials science, Reserpine, Microinjections, Guinea Pigs, Hydrostatic pressure, Combined use, Neurophysiology, Brain research, Osmotic minipump, Minipump-chemitrode, Kindling, Neurologic, Limbic System, Animals, Behaviour, Semipermeable membrane, Brain Mapping, Prostigmine, Constant flow, General Neuroscience, Minipump-chemitrode, Behaviour, Kindling, Prostigmine, Reserpine, Neurology & Neurosurgery, Neurosciences, Brain, Kindling, Cannula, Neostigmine, Electrophysiology, Cats, Rabbits, Neurology & Neurosurgery, Microelectrodes, Neuroscience, Biomedical engineering
Abstract

This paper describes a simple-to-build minipump-chemitrode assembly which can be used for long term electrophysiological, chemical and behavioural studies. This system consists of an osmotic minipump, a cannula and an array of nine electrodes which are connected to a miniature Winchester Socket. A detailed plan for construction of both the chemitrode and the minipump-chemitrode is given together with some suggestions for possible usages in brain research (such as kindling). The osmotic minipump consists of a collapsible reservoir of flexible, impermeable material, surrounded by a sealed layer containing an osmotic agent—all of which is contained by a semipermeable membrane. Imbibed water generates hydrostatic pressure on the flexible lining of the reservoir, gradually compressing it, producing a constant flow of its contents through the delivery portal.

Published
1981

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