Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/193784
Type: Artigo de periódico
Title: Effects Of Glucose On 45ca2+ Outflow, Cytosolic Ca2+ Concentration And Insulin Release From Freshly Isolated And Cultured Adult Rat Islets.
Author: Boschero, A C
Bordin, S
Herchuelz, A
Lebrun, P
Abstract: The present study aimed at comparing the effects of glucose on ionic and secretory events in freshly isolated and 5-7 day cultured rat pancreatic islets. The capacity of glucose to provoke insulin release was severely reduced in islets maintained in culture. Whether in freshly isolated or cultured islets, glucose provoked a marked and sustained decrease in 45Ca2+ outflow from islets deprived of extracellular Ca2+. In the presence of extracellular Ca2+ throughout, the magnitude of the glucose-induced secondary rise in 45Ca2+ outflow was reduced in cultured islets. Glucose provoked a weaker increase in [Ca2+]i in islet cells obtained from cultured islets than in islet cells dissociated from freshly isolated pancreatic islets. On the other hand, the stimulatory effect of carbamylcholine on 45Ca2+ outflow was unaffected by tissue culture. Lastly, in islet cells obtained from cultured islets, the increase in [Ca2+]i evoked by K+ depolarization averaged half of that observed in control experiments. These results indicate that the reduced secretory potential of glucose in cultured pancreatic islets can be ascribed to the inability of the nutrient secretagogue to provoke a suitable increase in Ca2+ influx.
Subject: Animals
Calcium
Carbachol
Cell Separation
Cells, Cultured
Cytosol
Female
Glucose
Insulin
Islets Of Langerhans
Kinetics
Potassium Chloride
Rats
Rats, Inbred Strains
Rights: fechado
Identifier DOI: 
Address: http://www.ncbi.nlm.nih.gov/pubmed/2285929
Date Issue: 1990
Appears in Collections:Artigos e Materiais de Revistas Científicas - Unicamp

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