Fig. 4.

Acute inhibition of CK2 selectively augments bethanechol-induced insulin secretion in vivo. WT mice (age: ∼8–12 wk) received a single dose of CX4945 (25 mg/kg, i.p.), followed by a 4-h fast. Mice were then injected with the muscarinic agonist bethanechol (2 mg/kg, s.c.) (A), glibenclamide (5 mg/kg i.p.) (B), arginine (1 g/kg i.p.) (C), or exendin-4 (12 nmol/kg i.p.) (D). Before CX4945 treatment, mice were either fed ad libitum (A, B, and D) or fasted for 5 h (C). Under these experimental conditions, bethanechol stimulates insulin release in WT mice via activation of β-cell M3Rs (17). Plasma insulin levels were measured at the indicated time points. Values are given as means ± SEM (n = 7 or 8 per group). *P < 0.05, compared with the corresponding control value.