Protein kinase C-mediated inhibition of an inward rectifier potassium channel by substance P in nucleus basalis neurons

Takano, Koji; Stanfield, Peter; Nakajima, Shigehiro; Nakajima, Yoshiaki

doi:10.1016/0896-6273(95)90338-0

Cited by 91 publications

(82 citation statements)

References 35 publications

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“…The details of the method for microinjection have already been reported elsewhere (9). GDP ␤ S was dissolved in 150 mM KCl at the concentration of 100 mM and GTP ␥ was dissolved in 150 mM KCl at the concentration of 10 mM.…”

Section: Methodsmentioning

confidence: 99%

Proadrenomedullin NH2-terminal 20 peptide inhibits the voltage-gated Ca2+ channel current through a pertussis toxin-sensitive G protein in rat pheochromocytoma-derived PC 12 cells.

Takano

Yamashita²,

Fujita³

1996

J. Clin. Invest.

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Section: Methodsmentioning

confidence: 99%

Proadrenomedullin NH2-terminal 20 peptide inhibits the voltage-gated Ca2+ channel current through a pertussis toxin-sensitive G protein in rat pheochromocytoma-derived PC 12 cells.

Takano

Yamashita²,

Fujita³

1996

J. Clin. Invest.

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“…The â_adrenergic receptor-mediated inhibition of IK(IR) in ventricular myocytes is mediated by cAMPdependent activation of PKA (Koumi, Wasserstrom & Ten Eick, 1995), while in spinal cord astrocytes â_adrenergic inhibition of IK(IR) current is mimicked by (Bu)µcAMP and forskolin but occurs independently of PKA activation (Roy & Sontheimer, 1995). In nucleus basalis neurones, protein kinase C mediates substance P-induced inhibition of IK(IR) (Takano, Stanfield, Nakajima & Nakajima, 1995). Stimulation of vasoactive intestinal peptide (VIP) receptors or GTPãS activation of G protein inhibits single IK(IR) channels in excised membrane patches from endothelial cells, suggesting a possible direct membrane-delimited regulation by a G protein (Pasyk, Cipris & Daniel, 1996).…”

Section: Modulation Of Ik(ir) By Crhmentioning

confidence: 99%

Corticotropin releasing hormone inhibits an inwardly rectifying potassium current in rat corticotropes

Kuryshev

Haak

Childs

et al. 1997

The Journal of Physiology

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The perforated‐patch‐clamp technique was used to identify an inwardly rectifying K+ current (IK(IR)) in cultured rat anterior pituitary cells highly enriched in corticotropes. IK(IR) was rapidly activating and highly selective for K+. The K+ conductance was approximately proportional to the square root of the extracellular K+ concentration. I K(IR) was blocked in a voltage‐dependent manner by external Ba2+ and Cs+, slightly attenuated by 5 mM 4‐aminopyridine (15% inhibition) and insensitive to 10 mM tetra‐ethylammonium, 2 mM Ca2+, 1 mM Cd2+ and 50 μM La3+. In physiological saline, 100 μM Ba2+, which inhibits 86% of IK(IR) at the cell resting potential, depolarized cells by 6.1 ± 0.7 mV from a mean resting potential of −59.6 ± 0.8 mV. Corticotropin releasing hormone (CRH), which activates adenylyl cyclase and stimulates adrenocorticotropic hormone (ACTH) secretion from corticotropes, inhibited IK(IR) by 25% and depolarized the cells by 10.2 ± 1.0 mV. Dibutyryl cAMP ((Bu)2cAMP) mimicked these effects. The membrane depolarization evoked by Ba2+ or CRH increased the cell firing frequency. Comparison of cells exhibiting a membrane potential of approximately −50 mV revealed that spike frequency in the presence of CRH (109 ± 7 spikes (5 min)−1) was greater than in control (60 ± 5 spikes (5 min)−1) or Ba2+‐treated (77 ± 15 spikes (5 min)−1) corticotropes. The data suggest that IK(IR) contributes to maintenance of the resting membrane potential of rat corticotropes. Inhibition of IK(IR) plays a role in, but does not account for all of, the membrane depolarization and enhancement of firing frequency evoked by CRH.

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“…Modulation of KIR2.3 but not KIR2.1 by PKC provides a novel mechanism for regulation of excitability in the nervous system. Recent reports have shown that neurotensin and substance-P act through PKC to decrease KIR currents in dopaminergic neurons of the substantia nigra (Wu & Wang, 1995) and neurons of the nucleus basalis (Takano, Stanfield, Nakajima & Nakajima, 1995), respectively. An inwardly rectifying K+ channel in T84 epithelial cells has also been shown to be downregulated by PKC (Tabeharani, Boucher, Eng & Hanrahan, 1994 …”

Section: Mutagenesismentioning

confidence: 99%

Protein kinase C inhibition of cloned inward rectifier (HRK1/KIR2.3) K+ channels expressed in Xenopus oocytes.

Henry

Pearson

Nichols

1996

The Journal of Physiology

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1. The effect of protein kinase activators on cloned inward rectifier channels expressed in Xenopus oocytes was examined using a two‐electrode voltage clamp. PKA activators caused no change in KIR1.1, KIR2.1, or KIR2.3 current. The PKC activators phorbol 12‐myristate 14‐acetate (PMA) and phorbol 12, 13‐dibutyrate (PDBu) inhibited KIR2.3 currents, but not KIR2.1 or KIR1.1 current. This inhibition was blocked by staurosporine. An inactive phorbol ester, 4 alpha‐phorbol 12, 13‐didecanoate (4 alpha‐PDD), had no effect on KIR2.3. 2. Upon changing solution from 2 to 98 microM K+, KIR2.3 but not KIR1.1 or KIR2.1 currents typically ‘ran down’ over 5 min to 60‐80% of maximum amplitude. Rundown occurred even if PMA was applied before changing to high [K+] solution, indicating that rundown was independent of PKC activity. Rundown was evoked by substituting NMG+ for Na+, showing that it results from low [Na+] and not from high [K+]. 3. These results suggest that KIR2.3, but not KIR1.1 or KIR2.1, is subject to regulation, both by PKC activation and as a consequence of low [Na+]o. The difference in secondary regulation may account for specific responses to PKC stimulation of tissues expressing otherwise nearly identical KIR channels.

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Protein kinase C-mediated inhibition of an inward rectifier potassium channel by substance P in nucleus basalis neurons

Cited by 91 publications

References 35 publications

Proadrenomedullin NH2-terminal 20 peptide inhibits the voltage-gated Ca2+ channel current through a pertussis toxin-sensitive G protein in rat pheochromocytoma-derived PC 12 cells.

Proadrenomedullin NH2-terminal 20 peptide inhibits the voltage-gated Ca2+ channel current through a pertussis toxin-sensitive G protein in rat pheochromocytoma-derived PC 12 cells.

Corticotropin releasing hormone inhibits an inwardly rectifying potassium current in rat corticotropes

Protein kinase C inhibition of cloned inward rectifier (HRK1/KIR2.3) K+ channels expressed in Xenopus oocytes.

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