Table 1.

Increase in cAMP, calcium, and VIP after treatment with increasing concentration of PACAP-27

[PACAP-27]applied	cAMP, picomoles per well	[Ca2+]i (R/R), peak/plateau	VIP, picograms per well
Vehicle	7.00  ± 0.57	0.75  ± 0.8	28  ± 2.8
0.1 nm	6.87  ± 0.41	n.d.	30  ± 0.95
1 nm	9.98  ± 0.06	n.d.	169  ± 10
10 nm	22.40  ± 0.20	3.2 ± 0.6/2.0 ± 0.4	998  ± 60
100 nm	22.22  ± 1.12	14.3 ± 1.1/5.9 ± 0.4	1259  ± 213
1000 nm	21.54  ± 0.44	n.d.	1115  ± 124

PACAP-27 applied to bovine chromaffin cells stimulates intracellular cAMP, calcium, and VIP concentrations. cAMP values were obtained after 30 min exposure to PACAP. In comparison with PACAP, cAMP levels measured after a comparable exposure to VIP ranged from 5.85 ± 0.23 pmol per well at 0.1 nm VIP to 6.9 ± 0.50 pmol per well at 100 nm VIP. cAMP was increased by 25 μm forskolin to 41.85 ± 0.91 pmol per well. Calcium values given are the 340/380 nm ratio of the calcium spike, over the 340/380 nm ratio of the calcium plateau (peak/plateau). n.d., Not determined. VIP levels in cells and culture medium were measured as described in Materials and Methods, after 72 hr exposure to PACAP.