Measuring plasma insulin dynamics. A: Three representative time courses of rapid sampling blood glucose (Glucose, mg/dL) and plasma insulin levels (Insulin, ng/mL)
from Cx36+/+ mice during hyperglycemic clamp. Sampling rate is one per minute. The x-axis indicates the time after glucose infusion is started. #, center of each pulse identified during pulse analysis. B: Three representative time courses of rapid sampling glucose and plasma insulin levels from Cx36−/− mice during hyperglycemic clamp, as in A. C: Time-averaged blood glucose in male littermate Cx36+/+ mice (black bars) and Cx36−/− mice (white bars) at 16–17 weeks of age before and during the hyperglycemic clamp, 40 min after the start of glucose infusion.
n = 10 and 8 mice in Cx36+/+ and Cx36−/− groups, respectively. D: Time-averaged plasma insulin levels corresponding to measurements made in C. E: Time-averaged glucose infusion rate required to establish glucose clamp in C. F: Norepinephrine levels at the end point of hyperglycemic clamp combined from both T0 and T40 groups, averaged over n = 8 mice in each experimental group. *, significant difference (P < 0.05, Student t test) comparing each measurement in Cx36+/+ and Cx36−/− mice.