Dynamics of Insulin Secretion from EndoC-βH1 β-Cell Pseudoislets in Response to Glucose and Other Nutrient and Nonnutrient Secretagogues

Table 1

Quantitative evaluation and statistical analysis of the insulin secretion rates from perifused EndoC-βH1 pseudoislets in response to stimulation with different secretagogues.

		Preperifusion	Perifusion
Stimulation by	Figure	Insulin secretion (ng/min)	Insulin secretion (ng/min)	N	value
A	B	C	D	E	F
Glucose (16.7 mM)	1(a)	0.244 ± 0.037	0.705 ± 0.104	7	<0.01
Glucose (16.7 mM) & IBMX (0.1 mM)	2(a)	0.176 ± 0.030	2.439 ± 0.474	4	<0.01
Glucose (16.7 mM) & forskolin (1 μM)	2(b)	0.418 ± 0.065	3.138 ± 0.792	5	<0.01
Glucose (10 mM) & glibenclamide (10 μM)	3(a)	0.194 ± 0.049	0.938 ± 0.203	5	<0.01
Glucose (10 mM) & Bay K 8644 (1 μM)	3(b)	0.206 ± 0.036	1.631 ± 0.276	5	<0.01
Leucine (20 mM) & glutamine (2 mM)	4(a)	0.275 ± 0.062	0.849 ± 0.262	4	<0.05
Glucose (10 mM) & KCl (40 mM)	4(b)	0.155 ± 0.041	0.681 ± 0.086	3	<0.01
Glucose (10 mM) & pyruvate (10 mM)	5(a)	0.281 ± 0.040	0.358 ± 0.051	4	Ns
Glucose (10 mM) & lactate (10 mM)	5(b)	0.257 ± 0.105	0.254 ± 0.073	5	Ns

For the different experimental conditions (A) as depicted in Figures 1–5 (B), the rates of insulin secretion for 100 perifused islets (expressed as ng/min) were calculated for the preperifusion phase (20 min) (C) and the perifusion phase (30 min) (D) with the numbers of experiments (E) and the values calculated with the unpaired t-test (F). Ns: no significance.