Expression and signal transduction of the glucagon receptor in betaTC3 cells

The expression and signal transduction of the glucagon receptor (GR) have been studied in betaTC3 cells. Northern blot and RT-PCR analysis indicated the expression of the GR gene in betaTC3 cells. One-5 nM glucagon stimulated a 2.5-fold increase in the IP(S) production. At glucagon concentrations higher than 5 nM, the production of IP(S) was blunted but not abolished. The accumulation of intracellular cAMP was observed following the stimulation with 5 nM of glucagon. A maximal 4.5-fold increase in cAMP was observed using 250 nM glucagon and higher. Comparative studies using a glucagon anatogonist, des-His1[Glu]9glucagon, showed no effect on intracellular cAMP and IPs in betaTC3 cells. Our data shows that the GR gene is expressed in betaTC3 cells. The GR in betaTC3 cells transmits its intracellular signal by causing the accumulation of both IP(S) and cAMP.