Modulation by D-glucose anomers of the effect of D-fructose upon 45Ca efflux from prelabelled rat pancreatic islets

2003 ◽  
Author(s):  
Hassan Jijakli ◽  
Hai-Xia Zhang ◽  
Abdullah Sener ◽  
Willy Malaisse
Keyword(s):  
Pancreatic Islets ◽  
Rat Pancreatic Islets ◽  
Glucose Anomers ◽  
45Ca Efflux

Sensitivity to Cd2+ but resistance to Ni2+ of Ca2+ inflow into rat pancreatic islets

1990 ◽  
Vol 258 (3) ◽  
pp. E529-E533 ◽  
Author(s):  
P. O. Plasman ◽  
M. Hermann ◽  
A. Herchuelz ◽  
P. Lebrun
Keyword(s):  
Pancreatic Islets ◽  
Insulin Release ◽  
Islet Cells ◽  
Excitable Cells ◽  
45Ca Uptake ◽  
Rat Pancreatic Islets ◽  
Cell Plasma ◽  
Different Types ◽  
45Ca Efflux ◽  
Ca2 Channels

The presence of different types [long lasting (L) and transient (T)] of active voltage-operated Ca2+ channels in islet cells was investigated by comparing the effects of Cd2+, Ni2+, and 1,4-dihydropyridines on 45Ca uptake, 45Ca efflux, and insulin release in intact rat pancreatic islets. In several other excitable cells the L-channel has been shown to be modulated by 1,4-dihydropyridines and Cd2+, whereas the T-channel was reported to be sensitive to Ni2+. Nifedipine and Cd2+ inhibited whereas BAY K 8644 enhanced the glucose (11.1, 22.2 mM)-stimulated short-term 45Ca uptake, 45Ca efflux, and insulin release. In contrast, the stimulatory effects of glucose (11.1, 22.2 mM) on 45Ca uptake, 45Ca efflux, and insulin release were unaffected by Ni2+. These findings confirm that glucose provokes Ca2+ entry mainly by activating voltage-sensitive Ca2+ channels of the L-type and suggest that the B-cell plasma membrane is not equipped with active T-type Ca2+ channels.

Regulation of calcium fluxes in pancreatic islets: two calcium movements' dissociated response to glucose

1980 ◽  
Vol 238 (2) ◽  
pp. E87-E95
Author(s):  
A. Herchuelz ◽  
W. J. Malaisse
Keyword(s):  
Glucose Metabolism ◽  
Low Temperature ◽  
Pancreatic Islets ◽  
Islet Cells ◽  
Calcium Fluxes ◽  
Rat Pancreatic Islets ◽  
Early Fall ◽  
45Ca Efflux ◽  
Secondary Rise

At normal extracellular 40Ca concentration (1.0--1.5 mM), D-glucose initially reduces and subsequently increases 45Ca efflux from prelabeled rat pancreatic islets, whether in the absence or presence of 20 mM Ca-EGTA. Thus, the initial fall cannot be attributed to a reuptake of effluent 45Ca. Both the fall and rise in effluent 45Ca represent sustained and rapidly reversible phenomena partially masked by one another. The dose-action relationship for the initial fall in 45Ca efflux (Km = 4.2 mM) differs vastly from that characterizing the secondary rise in 45Ca efflux (Km = 9.1 mM). Mannoheptulose, iodoacetate, and low temperature inhibit both the early fall and secondary rise in effluent radioactivity normally evoked by glucose. D-Glucose (8.3 mM) and D-glyceraldehyde (10 mM) exert comparable effects on 45Ca efflux. The initial fall and later increase in 45Ca efflux evoked by glucose, although dependent on the integrity of glucose metabolism, correspond to two distinct processes in the rapid regulation of Ca handling by the islet cells.

scholarly journals Glucose decreases extracellular adenosine levels in isolated mouse and rat pancreatic islets

Islets ◽  
2012 ◽  
Vol 4 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Gary K. Yang ◽  
Paul E. Squires ◽  
Faming Tian ◽  
Timothy J. Kieffer ◽  
Yin Nam Kwok ◽  
...  
Keyword(s):  
Pancreatic Islets ◽  
Extracellular Adenosine ◽  
Rat Pancreatic Islets
Sign in / Sign up

Export Citation Format

Share Document