scholarly journals The slow calcium-dependent potassium current in a myenteric neurone of the guinea-pig ileum.

1985 ◽  
Vol 361 (1) ◽  
pp. 315-337 ◽  
Author(s):  
G D Hirst ◽  
S M Johnson ◽  
D F van Helden
Keyword(s):  
Guinea Pig ◽  
Potassium Current ◽  
Guinea Pig Ileum ◽  
Calcium Dependent ◽  
Myenteric Neurone

scholarly journals The calcium current in a myenteric neurone of the guinea-pig ileum.

1985 ◽  
Vol 361 (1) ◽  
pp. 297-314 ◽  
Author(s):  
G D Hirst ◽  
S M Johnson ◽  
D F van Helden
Keyword(s):  
Guinea Pig ◽  
Calcium Current ◽  
Guinea Pig Ileum ◽  
Myenteric Neurone

Potassium currents and their modulation by muscarine and substance P in neuronal cultures from adult guinea pig celiac ganglia

1993 ◽  
Vol 69 (5) ◽  
pp. 1632-1644 ◽  
Author(s):  
S. Vanner ◽  
R. J. Evans ◽  
S. G. Matsumoto ◽  
A. Surprenant
Keyword(s):  
Substance P ◽  
Guinea Pig ◽  
Action Potential ◽  
Potassium Current ◽  
Potassium Currents ◽  
Resting Potential ◽  
Time Constants ◽  
Whole Cell ◽  
Calcium Dependent ◽  
Ganglion Neurons

1. Intracellular microelectrode and whole-cell patch-clamp recordings were obtained from adult guinea pig celiac ganglion neurons grown in tissue culture for 7-14 days. Over 90% of neurons showed phasic-type action-potential discharge with the use of either type of recording electrode; they stained immunohistochemically for catecholamines, tyrosine hydroxylase, and neuropeptide Y. Input resistance (140 M omega) and action-potential amplitude (103 mV) were significantly greater with whole-cell than with microelectrode recordings, but other passive electrical properties were similar. 2. Five potassium currents were characterized: an apamin-sensitive after hyperpolarizing current (IAHP), an apamin and tetraethylammonium-insensitive slow IAHP, an M-like current, a transient outward IA current, and a delayed rectifier IK current. A hyperpolarization-activated cationic Ih current was also present. The first three currents were not observed with whole-cell recordings. 3. Cadmium (200 microM), cobalt (1 mM), lanthanum (30 microM), or a low calcium/high magnesium solution blocked both IAHPS and the M-like current; barium (1 mM) also blocked these currents. 4. Kinetics of the M-like current were best described by a double exponential fit to deactivating tail currents with time constants of 50 and 390 ms at -50 mV. The apamin-sensitive and slow IAHP decayed exponentially with time constants of 145 ms and 3.5 s, respectively. There was no correlation between occurrence of M-like current (95% of neurons) and slow IAHP (40% of neurons), nor any correlation between magnitude of M-like current and IAHP in those cells exhibiting both currents. 5. Muscarine and substance P (SP) caused depolarizations or inward currents (under voltage clamp) at the resting potential (-55 mV) associated with a decreased membrane conductance. The slow IAHP and the M-like current, but not the apamin-sensitive IAHP nor the IA, were blocked by muscarine and SP (IC50 3 microM and 100 nM, respectively). Muscarine and SP also decreased a "leak" potassium current. 6. We conclude that celiac neurons express two calcium-dependent IAHP currents and a calcium-dependent M-current; these are seen by fine-tipped intracellular microelectrodes but not by whole-cell patch electrodes. These currents are not required for spike frequency accommodation. Muscarine and SP reduce these currents, as well as voltage-independent leakage potassium current.

Anti-inflammatory effect of Mitragyna speciosa crude methanol extract on the guinea pig ileum

Planta Medica ◽  
2009 ◽  
Vol 75 (09) ◽  
Author(s):  
WM Shaik Mossadeq ◽  
K Syamimi ◽  
MP Azyyati ◽  
ZA Zakaria ◽  
AK Arifah ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Methanol Extract ◽  
Guinea Pig Ileum ◽  
Mitragyna Speciosa ◽  
Anti Inflammatory ◽  
Crude Methanol Extract ◽  
Inflammatory Effect

Preparation and properties of three analogues of [5-leucine]enkephalin, substrates for enzyme conversion studies

1985 ◽  
Vol 50 (6) ◽  
pp. 1329-1334
Author(s):  
Jaroslav Vičar ◽  
Linda Servítová ◽  
Martin Flegel ◽  
Karel Hauzer ◽  
Tomislav Barth
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Guinea Pig ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Guinea Pig Ileum ◽  
Opioid Activity ◽  
C Terminus ◽  
N Terminus ◽  
Fragment Condensation

Analogues of [5-Leu]enkephalin, prolonged by methionine on the N-terminus or, by lysine or methionine on the C-terminus were prepared by fragment condensation, purified by ion exchange chromatography or high-pressure liquid chromatography. The substances were characterised by their opioid activity in a test on guinea-pig ileum in comparison with the activity of [5-Leu]enkephalin.

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