We examined the effects of neuropeptide Y (NPY) and pancreatic polypeptide on calcium currents (I(Ca)) in acutely dissociated neurons from the adult rat superior cervical ganglion. We found that NPY inhibited the I(Ca) with an estimated IC50 value of 140 nM. This inhibitory effect appeared to be restricted to a subset of cells which were smaller in diameter than the general population. The effect of NPY on the I(Ca) was prevented by pretreatment with pertussis toxin, suggesting the involvement of a GTP- binding protein of the G(i) or G(o) subtype. ω-conotoxin GVIA also occluded the effects of NPY, which suggests that these were directed toward N-type Ca++ channels. The effects of NPY were mimicked by the fragment NPY (13- 36) but not by peptide YY, indicating that a receptor distinct from a Y1- or a Y2-like NPY receptor was involved. Finally, we also observed that pancreatic polypeptide inhibited the I(Ca), suggesting that a pancreatic polypeptide receptor is also present on superior cervical ganglion neurons.
|Original language||English (US)|
|Number of pages||7|
|Journal||Journal of Pharmacology and Experimental Therapeutics|
|State||Published - 1993|
ASJC Scopus subject areas
- Molecular Medicine