Fig. 2.

PKA-dependent potentiation of GSIS by 8-pCPT-2′-O-Me-cAMP-AM. A: human islets were equilibrated in KRB containing 2.8 or 10 mM glucose (2.8 G or 10 G, respectively) with or without added 8-pCPT-2′-O-Me-cAMP-AM (10 μM; ESCA-AM), dibutyryl-cAMP-AM (Bt₂-cAMP-AM; 10 μM), or 6-Bnz-cAMP-AM (10 μM). B: basal insulin secretion measured under conditions in which the KRB contained 2.8 mM glucose with or without added 0.1% DMSO, H-89 (10 μM), or Rp-8-CPT-cAMPS (200 μM). C and D: GSIS measured under conditions in which the KRB contained 10 mM glucose with or without added DMSO, ESCA-AM, phosphate-AM₃ (Phos-AM₃), H-89 (10 μM), or Rp-8-CPT-cAMPS (200 μM). Values of fold stimulation in C and D were calculated by measuring secreted insulin under conditions in which islets were exposed to KRB containing 2.8 or 10 mM glucose. Results obtained in 3 static incubation assays using islets from 3 donors are summarized in A–D. *P < 0.05, t-test. Error bars denote the mean ± SE for triplicate determinations.