title: Neuropeptide Y modulates calcium channels in hamster submandibular ganglion neurons.
abstract: It is established that neuropeptide Y (NPY) is a transmitter of parasympathetic secretory impulses in submandibular gland. The neuropeptides substance P, vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP) are likely mediators of secretory parasympathetic responses of the gland. Previously, we have shown that substance P, VIP and CGRP modulate voltage-dependent Ca(2+) channels (VDCCs) in hamster submandibular ganglion (SMG) neurons. In this study, we attempt to characterize the effect of NPY on VDCCs current using Ba(2+) (I(Ba)) in SMG neurons. Application of NPY caused both facilitation and inhibition of L-type and N/P/Q-type I(Ba), respectively. Intracellular dialysis of the Gα(s)-protein antibody attenuated the NPY-induced facilitation of I(Ba). The adenylate cyclase (AC) inhibitor, as well as protein kinase A (PKA) inhibitor attenuated the NPY-induced facilitation of I(Ba). Intracellular dialysis of the Gα(i)-protein antibody attenuated the NPY-induced inhibition of I(Ba). Application of a strong depolarizing voltage prepulse attenuated the NPY-induced inhibition of I(Ba). These results indicate that NPY facilitates L-type VDCCs via Gα(s)-protein involving AC and PKA. On the other hand, NPY also inhibits N/P/Q-type VDCCs via Gα(i)-protein βγ subunits in the SMG neurons.
authors.affiliation: Department of Physiology, Tokyo Dental College, 1-2-2 Masago, Mihama-ku, Chiba 261-8502, Japan. tendoh@tdc.ac.jp
authors.forename: Takayuki
authors.initials: T
authors.lastname: Endoh
authors.forename: Hiromi
authors.initials: H
authors.lastname: Nobushima
authors.forename: Masakazu
authors.initials: M
authors.lastname: Tazaki
mesh_terms: D000818:Animals; D015220:Calcium Channels / Q000378:metabolism*; D006224:Cricetinae; D005726:Ganglia, Parasympathetic / Q000378:metabolism*; D008647:Mesocricetus; D009474:Neurons / Q000378:metabolism*; D009478:Neuropeptide Y / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D012463:Saliva / Q000378:metabolism; D013363:Submandibular Gland / Q000294:innervation / Q000378:metabolism*
chemical_list: D015220:Calcium Channels; D009478:Neuropeptide Y