Fig. 7. Gd3+ inhibits store-operated influx of Mn2+ in response to carbachol in an individual ß-cell. Pancreatic ß-cells were loaded with fura-2 in hyperpolarizing medium containing 400 µM diazoxide, 20 mM glucose and 1.28 mM Ca2+. The same medium lacking indicator but containing 50 µM methoxyverapamil was present at the beginning of the experiment. The medium was then supplemented with 200 µM Mn2+ (upper bar), 100 µM carbachol (Carb; middle bar) and 1 µM Gd3+ (lower bar). The cytoplasmic Mn2+ concentration (A) is shown above [Ca2+]i (B), which is not reliable after the introduction of Mn2+ (shaded area). The broken lines indicate the rate of change in Mn2+ concentration immediately after addition of Mn2+ (1), after subsequent addition of 100 µM carbachol (2) and 1 µM Gd3+ (3). The results are representative of nine independent experiments.
