Agonists for neuropeptide Y receptor subtypes NPY-1 and NPY-2 have opposite actions on rat nodose neuron calcium currents.
1. The whole-cell variation of the patch-clamp technique was used to study the effect of neuropeptide Y (NPY) and preferential agonists for the NPY-1 and NPY-2 receptor subtypes on voltage-dependent calcium currents in acutely dissociated postnatal rat nodose ganglion neurons. 2. Both low- and high-threshold calcium current components were present. NPY altered voltage-dependent calcium currents in approximately 50% of neurons studied. NPY (0.1-100 nM, ED50 6 nM) decreased the peak amplitude of transient high-threshold calcium currents in approximately 45% of the neurons. NPY (100 nM) decreased the peak amplitude of these currents 31 +/- 5% (mean +/- SE). However, in approximately 5% of the neurons NPY (100 nM) caused a reversible and reproducible increase in transient high-threshold calcium currents of 21 +/- 4%. NPY did not affect either transient low-threshold or slowly inactivating high-threshold calcium current components. 3. Application of the C-terminal fragment NPY 13-36 (100 nM), a preferential agonist for NPY-2 receptors, reversibly decreased the peak amplitude of transient high-threshold calcium currents by 26 +/- 5% in 9 of 20 cells (45%). Application of [Pro34]-NPY (100 nM), a preferential agonist for NPY-1 receptors, reversibly increased the peak amplitude of transient high-threshold calcium currents 20 +/- 4% in 23 out of 48 neurons (48%). Six of 20 neurons (30%) responded to application of both agonists. Neither the NPY-1 nor NPY-2 agonists affected transient low-threshold or slowly inactivating high-threshold calcium current components.(ABSTRACT TRUNCATED AT 250 WORDS)
Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor 48109.
J W
JW
Wiley
R A
RA
Gross
R L
RL
MacDonald
D000818:Animals; D015220:Calcium Channels / Q000187:drug effects* / Q000502:physiology; D002478:Cells, Cultured; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009478:Neuropeptide Y / Q000494:pharmacology / Q000502:physiology*; D009620:Nodose Ganglion / Q000187:drug effects* / Q000502:physiology; D010446:Peptide Fragments / Q000494:pharmacology; D051381:Rats; D017476:Receptors, Neuropeptide Y / Q000145:classification / Q000187:drug effects* / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects* / Q000502:physiology; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D015220:Calcium Channels; D009478:Neuropeptide Y; D010446:Peptide Fragments; D017476:Receptors, Neuropeptide Y; D010566:Virulence Factors, Bordetella; C062924:neuropeptide Y (13-36); C048612:neuropeptide Y C-terminal flanking peptide