Cyclosporin A induces a biphasic increase in KCl-induced calcium influx in GH3 pituitary cells. 1999

Y C Chou, and J C Fong
Institute of Biochemistry, National Yang-Ming University, Taipei, Taiwan, Republic of China.

The role of calcineurin in modulation of calcium channel activity was examined in GH3 pituitary cells by using its selective inhibitor cyclosporin A. While cyclosporin A had little effect on basal activity, it induced a biphasic increase in K+-induced 45Ca2+ influx. Cyclosporin A rapidly increased K+-induced 45Ca2+ influx to approximately 140% of control in 1 h and the increment maintained at this magnitude for 1-8 h. Thereafter, K+-induced 45Ca2+ influx gradually increased further to approximately 220% after 24 h exposure to this compound. In the presence of anisomycin, however, the increase occurred at the latter phase was abolished. In addition, the increased calcium influx in cyclosporin A-pretreated cells had a similar sensitivity to KCl and verapamil as in untreated cells. Measurement of intracellular Ca2+ level by Fura-2 analysis indicated that [Ca2+]i increase induced by high K+ or vasoactive intestinal peptide was similarly augmented in cyclosporin A-pretreated cells. Thus the results of this study suggest that calcineurin may play a tonic control on L-type Ca2+ channel, and inhibition of this enzyme may induce a subsequently protein synthesis-dependent higher channel activity.

UI MeSH Term Description Entries
D010902 Pituitary Gland A small, unpaired gland situated in the SELLA TURCICA. It is connected to the HYPOTHALAMUS by a short stalk which is called the INFUNDIBULUM. Hypophysis,Hypothalamus, Infundibular,Infundibular Stalk,Infundibular Stem,Infundibulum (Hypophysis),Infundibulum, Hypophyseal,Pituitary Stalk,Hypophyseal Infundibulum,Hypophyseal Stalk,Hypophysis Cerebri,Infundibulum,Cerebri, Hypophysis,Cerebrus, Hypophysis,Gland, Pituitary,Glands, Pituitary,Hypophyseal Stalks,Hypophyses,Hypophysis Cerebrus,Infundibular Hypothalamus,Infundibular Stalks,Infundibulums,Pituitary Glands,Pituitary Stalks,Stalk, Hypophyseal,Stalk, Infundibular,Stalks, Hypophyseal,Stalks, Infundibular
D011189 Potassium Chloride A white crystal or crystalline powder used in BUFFERS; FERTILIZERS; and EXPLOSIVES. It can be used to replenish ELECTROLYTES and restore WATER-ELECTROLYTE BALANCE in treating HYPOKALEMIA. Slow-K,Chloride, Potassium
D002118 Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002460 Cell Line Established cell cultures that have the potential to propagate indefinitely. Cell Lines,Line, Cell,Lines, Cell
D004347 Drug Interactions The action of a drug that may affect the activity, metabolism, or toxicity of another drug. Drug Interaction,Interaction, Drug,Interactions, Drug
D004791 Enzyme Inhibitors Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction. Enzyme Inhibitor,Inhibitor, Enzyme,Inhibitors, Enzyme
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D016572 Cyclosporine A cyclic undecapeptide from an extract of soil fungi. It is a powerful immunosupressant with a specific action on T-lymphocytes. It is used for the prophylaxis of graft rejection in organ and tissue transplantation. (From Martindale, The Extra Pharmacopoeia, 30th ed). Cyclosporin A,Ciclosporin,CsA-Neoral,CyA-NOF,Cyclosporin,Cyclosporine A,Neoral,OL 27-400,Sandimmun,Sandimmun Neoral,Sandimmune,CsA Neoral,CsANeoral,CyA NOF,OL 27 400,OL 27400
D017136 Ion Transport The movement of ions across energy-transducing cell membranes. Transport can be active, passive or facilitated. Ions may travel by themselves (uniport), or as a group of two or more ions in the same (symport) or opposite (antiport) directions. Antiport,Ion Cotransport,Ion Exchange, Intracellular,Symport,Uniport,Active Ion Transport,Facilitated Ion Transport,Passive Ion Transport,Cotransport, Ion,Exchange, Intracellular Ion,Intracellular Ion Exchange,Ion Transport, Active,Ion Transport, Facilitated,Ion Transport, Passive,Transport, Active Ion,Transport, Ion
D051381 Rats The common name for the genus Rattus. Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus

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