3 resultados para Pharmacy and pharmacology
em National Center for Biotechnology Information - NCBI
Resumo:
This paper argues that historical works in pharmacy are important tools for the clinician as well as the historian. With this as its operative premise, delineating the tripartite aspects of pharmacy as a business enterprise, a science, and a profession provides a conceptual framework for primary and secondary resource collecting. A brief history and guide to those materials most essential to a historical collection in pharmacy follows. Issues such as availability and cost are discussed and summarized in checklist form. In addition, a glossary of important terms is provided as well as a list of all the major U.S. dispensatories and their various editions. This paper is intended to serve as a resource for those interested in collecting historical materials in pharmacy and pharmaco-therapeutics as well as provide a history that gives context to these classics in the field. This should provide a rationale for selective retrospective collection development in pharmacy.
Resumo:
A second isoform of the human vesicular monoamine transporter (hVMAT) has been cloned from a pheochromocytoma cDNA library. The contribution of the two transporter isoforms to monoamine storage in human neuroendocrine tissues was examined with isoform-specific polyclonal antibodies against hVMAT1 and hVMAT2. Central, peripheral, and enteric neurons express only VMAT2. VMAT1 is expressed exclusively in neuroendocrine, including chromaffin and enterochromaffin, cells. VMAT1 and VMAT2 are coexpressed in all chromaffin cells of the adrenal medulla. VMAT2 alone is expressed in histamine-storing enterochromaffin-like cells of the oxyntic mucosa of the stomach. The transport characteristics and pharmacology of each VMAT isoform have been directly compared after expression in digitonin-permeabilized fibroblastic (CV-1) cells, providing information about substrate feature recognition by each transporter and the role of vesicular monoamine storage in the mechanism of action of psychopharmacologic and neurotoxic agents in human. Serotonin has a similar affinity for both transporters. Catecholamines exhibit a 3-fold higher affinity, and histamine exhibits a 30-fold higher affinity, for VMAT2. Reserpine and ketanserin are slightly more potent inhibitors of VMAT2-mediated transport than of VMAT1-mediated transport, whereas tetrabenazine binds to and inhibits only VMAT2. N-methyl-4-phenylpyridinium, phenylethylamine, amphetamine, and methylenedioxymethamphetamine are all more potent inhibitors of VMAT2 than of VMAT1, whereas fenfluramine is a more potent inhibitor of VMAT1-mediated monamine transport than of VMAT2-mediated monoamine transport. The unique distributions of hVMAT1 and hVMAT2 provide new markers for multiple neuroendocrine lineages, and examination of their transport properties provides mechanistic insights into the pharmacology and physiology of amine storage in cardiovascular, endocrine, and central nervous system function.
Resumo:
Application of L-glutamate to retinal glial (Müller) cells results in an inwardly rectifying current due to the net influx of one positive charge per molecule of glutamate transported into the cell. However, at positive potentials an outward current can be elicited by glutamate. This outward current is eliminated by removal of external chloride ions. Substitution of external chloride with the anions thiocyanate, perchlorate, nitrate, and iodide, which are known to be more permeant at other chloride channels, results in a considerably larger glutamate-elicited outward current at positive potentials. The large outward current in external nitrate has the same ionic dependence, apparent affinity for L-glutamate, and pharmacology as the glutamate transporter previously reported to exist in these cells. Varying the concentration of external nitrate shifts the reversal potential in a manner consistent with a conductance permeable to nitrate. Together, these results suggest that the glutamate transporter in retinal glial cells is associated with an anionic conductance. This anionic conductance may be important for preventing a reduction in the rate of transport due the depolarization that would otherwise occur as a result of electrogenic glutamate uptake.