These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Substance P produces an inward current by suppressing voltage-dependent and -independent K+ currents in bullfrog primary afferent neurons.
    Author: Ishimatsu M.
    Journal: Neurosci Res; 1994 Feb; 19(1):9-20. PubMed ID: 7516511.
    Abstract:
    A whole-cell patch-clamp study was carried out to examine the effect of substance P (SP) on the excitability of neurons in bullfrog dorsal root ganglia (DRG). SP (3 nM to 1 microM) produced an inward current associated with decreased membrane conductance at voltage range between -10 and -130 mV. Neurokinin A (NKA) and neurokinin B (NKB) also produced the inward current in DRG cells; the rank order of agonist potency was NKA = SP much greater than NKB. An antagonist for SP receptors, [D-Arg1, D-Trp7,9, Leu11]SP, did not prevent the response to SP. SP (3 nM to 1 microM) suppressed the voltage-dependent non-inactivating K+ current, the M-current (IM) by reducing the maximum M-conductance. A voltage-independent background K+ current, IK(B), could be recorded at a hyperpolarizing voltage (< or = -60 mV) from DRG neurons. SP (3 nM to 1 microM) produced the inward current associated with decreased IK(B) at a holding potential more negative than -60 mV. The SP-induced inward current reversed its polarity at the equilibrium potential for K ions. Intracellular dialysis with Cs+ blocked the SP-induced responses. Depletion of intracellular ATP reduced SP-induced inward current. These results suggest that the SP-induced inward current was due to suppression of both the IM and IK(B) that are regulated by intracellular activity of ATP in bullfrog DRG neurons.
    [Abstract] [Full Text] [Related] [New Search]