Regulation of 3-O-methyl-D-glucose uptake in isolated bovine adrenal chromaffin cells.
We showed earlier that insulin stimulated sugar transport in adrenal chromaffin cells (Bigornia, L. and Bihler, I. Biochim. Biophys. Acta 885, 335-344). Transport regulation and its Ca2+ -dependence was further investigated in isolated bovine adrenal chromaffin cells, serving as a model of a homogeneous neuronal cell population. Uptake of the nonmetabolizable glucose analogue, 3-O-methyl-D-glucose was stimulated by hyperosmolar medium, and this effect was abolished in the absence of external Ca2+, or depressed in the presence of La3+ or the slow Ca2+ channel blocker methoxyverapamil. Basal transport was also stimulated by factors (acetylcholine, carbamylcholine, low-Na+ medium), which cause Ca2+ -dependent catecholamine release, and these effects were abolished in Ca2+ -free medium. In addition insulin, acetylcholine, hyperosmolar and low-Na+ medium significantly increased 45Ca uptake. Thus, glucose transport in adrenal chromaffin cells was stimulated by insulin and hyperosmolarity in a Ca2+ -dependent manner, as in muscle. Sensitivity to secretory stimuli, a regulatory feature perhaps characteristic of this cell type, was also demonstrated. In contrast to muscle, sugar transport was not affected by Na+ -pump inhibition, metabolic inhibitors or the Na+ ionophore monensin, suggesting that Ca2+ influx by Na+/Ca2+ exchange does not play a significant role in the activation of sugar transport in chromaffin cells.
Bigornia
L
L
Wattis
M
M
Bihler
I
I
D019325:3-O-Methylglucose; D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002395:Catecholamines / Q000378:metabolism; D002417:Cattle; D002837:Chromaffin Granules / Q000378:metabolism*; D002838:Chromaffin System / Q000378:metabolism*; D004983:Ethanolamines / Q000494:pharmacology; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology; D008757:Methylglucosides / Q000378:metabolism*; D008759:Methylglycosides / Q000378:metabolism*; D009994:Osmolar Concentration; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism
D002395:Catecholamines; D004983:Ethanolamines; D007328:Insulin; D008757:Methylglucosides; D008759:Methylglycosides; D019325:3-O-Methylglucose; D000001:Calcimycin; D012964:Sodium; C009546:triethanolamine; D000109:Acetylcholine; D011188:Potassium; D002118:Calcium