Table 1

Modulation of CGRP-release from adult rat trigeminal ganglion neurons

Treatment	Basal	Forskolin	Forskolin ⁺Treatment	n
GR79236X	65 ± 7	288 ± 12^1-a	139 ± 23^1-b	4
CGS21680	53 ± 12	232 ± 18^1-a	238 ± 14	3
2-CI-IB-MECA	37 ± 10	188 ± 35^1-a	195 ± 37	4
Sumatriptan	37 ± 10	193 ± 33^1-a	185 ± 34	4
Fentanyl	45 ± 10	219 ± 36^1-a	91 ± 18^1-b	4

The CGRP concentration (mean ± S.E.M.; pg ml⁻¹) in the culture medium of trigeminal ganglion neurons was determined after a 30-min incubation period in the presence of forskolin (3 μM) with or without the following agents: GR79236X (100 nM), CGS21680 (1 μM), 2-CI-IB-MECA (1 μM), sumatriptan (1 μM), or fentanyl (100 nM). Basal values represent the CGRP secretion obtained after treatment with the appropriate vehicle control. None of the treatments had any significant effect on basal levels of CGRP secretion (data not shown).

↵1-a For every preparation of trigeminal primary cultures, forskolin induced a significant increase in CGRP release over basal (P < 0.001).
↵1-b Significantly different from that incubated with forskolin alone (P < 0.01).