Glucose-stimulated efflux of indo-1 from pancreatic beta-cells is reduced by probenecid.
Indo-1 loaded pancreatic beta-cells, isolated from obese hyperglycaemic mice, were studied with respect to cytoplasmic free Ca2+ concentration ([Ca2+]i), efflux of indicator and insulin release. In the absence of glucose there was a continuous efflux of indo-1 which increased upon stimulation with 20 mM of the sugar. The anion exchange inhibitor probenecid reduced both basal efflux of indo-1 and prevented that promoted by glucose. Measurements of [Ca2+]i and insulin release revealed similar results as previously reported with quin-2 and fura-2. Furthermore, probenecid did not influence the [Ca2+]i responses. It is thus possible to reduce efflux of indo-1 probenecid and thereby improve the measurements of [Ca2+]i in pancreatic beta-cells.
Arkhammar
P
P
Department of Endocrinology, Karolinska Institute, Karolinska Hospital, Stockholm, Sweden.
Nilsson
T
T
Berggren
P O
PO
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002217:Carbachol / Q000494:pharmacology; D003600:Cytosol / Q000378:metabolism; D005260:Female; D005456:Fluorescent Dyes; D005947:Glucose / Q000494:pharmacology*; D066298:In Vitro Techniques; D007211:Indoles; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D051379:Mice; D008820:Mice, Obese; D011339:Probenecid / Q000494:pharmacology*
D005456:Fluorescent Dyes; D007211:Indoles; D007328:Insulin; D002217:Carbachol; D005947:Glucose; C048960:indo-1; D011339:Probenecid; D002118:Calcium