Neuropeptide Y modulates calcium channels in hamster submandibular ganglion neurons

作者：Endoh Takayuki^*; Nobushima Hiromi; Tazaki Masakazu

来源：Neuroscience Research, 2012, 73(4): 275-281.

DOI：10.1016/j.neures.2012.05.002

• Neuropeptide Y
• Submandibular ganglion
• Calcium channel currents
• Saliva secretion

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 Ca2+ channels (VDCCs) in hamster submandibular ganglion (SMG) neurons. In this study, we attempt to characterize the effect of NPY on VDCCs current using Ba2+ (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 G alpha(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 G alpha(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 G alpha(s)-protein involving AC and PKA. On the other hand, NPY also inhibits N/P/Q-type VDCCs via G alpha(i)-protein beta gamma subunits in the SMG neurons.

• 出版日期2012-8