Skip to main content
. 2014 Apr 17;289(22):15751–15763. doi: 10.1074/jbc.M114.568683

FIGURE 2.

FIGURE 2.

Glucose-stimulated insulin secretion (GSIS) and arginine-potentiated glucagon secretion from GPR120 WT and KO islets. A, ability of islets to secrete insulin in response to glucose was compared in islets isolated from GPR120 WT and KO mice. GPR120 WT islets secreted 1408 ± 278.9 pg/ml insulin at basal glucose levels (2.67 mm) and secreted 13824 ± 2738 pg/ml insulin in response to 16.67 mm glucose. GPR120 KO islets secreted 1321 ± 315.9 pg/ml insulin at basal glucose levels (2.67 mm) and secreted 12441 ± 1073 pg/ml insulin in response to 16.67 mm glucose. B, expressed as a stimulation index, 16.67 mm glucose increased insulin secretion relative to 2.67 mm glucose 9.8 ± 1.9-fold in GPR120 WT islets and 9.4 ± .8-fold in GPR120 KO islets. C, ability of islets to secrete glucagon in response to arginine was compared in islets isolated from GPR120 WT and KO mice. GPR120 WT islets secreted 410 ± 106 pg/ml glucagon at basal arginine levels (2 mm) and secreted 286 ± 43 pg/ml, 1664 ± 270 pg/ml and 3586 ± 756 pg/ml glucagon in response to 5, 10, and 25 mm arginine. GPR120 KO islets secreted 863 ± 92 pg/ml glucagon at basal arginine levels (2 mm) and secreted 575 ± 91 pg/ml, 3057 ± 209 pg/ml, and 9106 ± 2340 pg/ml glucagon in response to 5, 10, and 25 mm arginine. D, expressed as a stimulation index, 5, 10, and 25 mm arginine increased glucagon secretion relative to 2 mm arginine 0.7 ± 0.1-fold, 4.1 ± 0.7-fold, and 8.7 ± 1.8- fold, respectively, from GPR120 WT islets and 0.7 ± 0.1-fold, 3.5 ± .2-fold, and 10.5 ± 2.7-fold, respectively, from GPR120 KO islets. E, to determine if basal glucagon secretion (2 mm arginine) is different between GPR120 WT and GPR120 KO islets, basal glucagon secretion was combined across all experiments performed. GPR120 WT islets secreted 752 ± 125.6 pg/ml and GPR120 KO islets secreted 629.2 ± 42.1 pg/ml glucagon at basal arginine levels (p = 0.4, n = 24–25). F, total glucagon and insulin content was compared in islets isolated from GPR120 WT and GPR120 KO mice on normal chow diet. GPR120 WT islets contained 73.3 ± 6.4 ng/ml and GPR120 KO islets contained 77.1 ± 7.8 ng/ml glucagon per 10 islets (p = 0.71, n = 17–22). GPR120 WT islets contained 5327 ± 241 ng/ml and GPR120 KO islets contained 3687 ± 243 ng/ml insulin per 10 islets (p < 0.0001, n = 17–22).