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. 2004 Feb 15;113(4):635–645. doi: 10.1172/JCI20518

Figure 6.

Figure 6

cAMP, carbachol, and insulin secretion. (a) IBMX and insulin secretion. Islets were perifused successively with 2.8 mM glucose for 10 minutes, 16.7 mM glucose for 10 minutes, 2.8 mM glucose for 20 minutes, first in the absence and then in the presence of IBMX 100 μM. Shown are the AUCs of insulin responses normalized to WT values set at 1. Absolute values of AUCs for WT are 0.32% of insulin content (without IBMX) and 0.99 % of insulin content (with IBMX). (b) Forskolin and insulin secretion. Islets were perifused in the presence of 100 μM IBMX as follows: 2.8 mM glucose for 10 minutes, 16.7 mM glucose for 10 minutes, 2.8 mM glucose for 20 minutes, 16.7 mM glucose + forskolin (10 μM) for 10 minutes, and 2.8 mM glucose for 25 minutes. Results are AUCs of insulin responses (n = 4). Inset: double-KO values normalized to WT values, set at 1. (c) Static incubations of isolated islets. Insulin secretion from 10 islets incubated for 15 minutes at 16.7 mM glucose in the presence or absence of IBMX 100 μM and forskolin (FSK) 10 μM (n = 3 separate experiments). Inset, double-KO values normalized to WT values, set at 1. (d) cAMP accumulation in 20 islets incubated in presence of IBMX 250 μM with or without forskolin 10 μM (n = 4–9, pooled from two separate experiments). Data are expressed as means ± SE of femtomoles cAMP accumulated per islet during 20 minutes. **P < 0.01, §P < 0.005, §§P < 0.001 vs. WT controls. (e) Carbachol and insulin secretion. Islets were perifused with 16.7 mM glucose in the presence or absence of carbachol (Cch, 1 μM). The data are AUCs of secreted insulin. Data are mean ± SEM (n = 3).