PMID- 8982499
OWN - NLM
STAT- MEDLINE
DCOM- 19970401
LR  - 20190512
IS  - 0007-1188 (Print)
IS  - 0007-1188 (Linking)
VI  - 119
IP  - 8
DP  - 1996 Dec
TI  - P2x-purinoceptors of myenteric neurones from the guinea-pig ileum and their 
      unusual pharmacological properties.
PG  - 1541-8
AB  - 1. Whole-cell and outside-out patch clamp recordings were used to characterize 
      the physiological and pharmacological properties of the P2x-purinoceptors of 
      myenteric neurones from the guinea-pig ileum. 2. Adenosine 5'-triphosphate (ATP) 
      and analogues (1-3000 microM) evoked a rapid inward current in > 90% of all 
      recorded neurones. The reversal potential of this current was dependent on the 
      extracellular sodium concentration, at +14 +/- 1.9, 0 +/- 1.6 and -12 +/- 1 mV 
      for 166, 83 and 42 mM of sodium, respectively. The fast activation and 
      inactivation of this current occurred even when guanosine 5'-triphosphate (GTP) 
      was omitted from the pipette solution or substituted with an equimolar 
      concentration of guanosine 5'-o-[2-thiotriphosphate] (GTP-gamma-S). Single 
      channel currents were observed when these outside-out membrane patches were 
      exposed to ATP (10-30 microM). These channels have a unitary conductance of about 
      17 picosiemens. 3. The rank-order of potency of the agonists used to induce the 
      whole-cell currents was: ATP-gamma-S = ATP = 2-methylthio-ATP (2-Me-S-ATP) > > 
      alpha, beta-methylene ATP = beta, gamma-methylene ATP; adenosine and uridine 
      5'-triphosphate (UTP) (up to 1 mM) were inactive. 4. 
      Pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) (1-30 microM) 
      antagonized the effects of ATP (1 mM) with an IC50 of 4 microM. alpha, 
      beta-Methylene ATP (100 microM) did not affect the ATP (30 microM)-induced 
      current. Cibacron Blue 3GA increased the ATP activated cationic current whereas 
      Basilen Blue E-3G had a very weak antagonistic effect (IC50 > or = 3 mM). Suramin 
      potentiated the currents induced by ATP through a mechanism that was independent 
      of its inhibitory effect on ectonucleotidase activity, as suramin also 
      potentiated the effect of alpha, beta-methylene ATP (an ATP analogue that is 
      resistant to nucleotidases). 5. In conclusion, the myenteric P2x-purinoceptor 
      shares some properties with other purinoceptors in particular with the P2x4- and 
      P2x6-purinoceptors. This receptor has also some unusual pharmacological 
      properties suggesting that myenteric neurones express a novel subtype of 
      P2x-purinoceptors. The properties of this receptor, however, might be a result of 
      the combination of two or more of the homomeric purinoceptors so far 
      characterized.
FAU - Barajas-Lopez, C
AU  - Barajas-Lopez C
AD  - Department of Biomedical Sciences, McMaster University, Hamilton, Ontario, 
      Canada.
FAU - Huizinga, J D
AU  - Huizinga JD
FAU - Collins, S M
AU  - Collins SM
FAU - Gerzanich, V
AU  - Gerzanich V
FAU - Espinosa-Luna, R
AU  - Espinosa-Luna R
FAU - Peres, A L
AU  - Peres AL
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Br J Pharmacol
JT  - British journal of pharmacology
JID - 7502536
RN  - 0 (Ion Channels)
RN  - 0 (Platelet Aggregation Inhibitors)
RN  - 0 (Purinergic P2 Receptor Agonists)
RN  - 0 (Purinergic P2 Receptor Antagonists)
RN  - 0 (Receptors, Purinergic P2)
RN  - 149017-66-3 (pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid)
RN  - 5V5IOJ8338 (Pyridoxal Phosphate)
RN  - 6032D45BEM (Suramin)
RN  - 8L70Q75FXE (Adenosine Triphosphate)
SB  - IM
MH  - Adenosine Triphosphate/physiology
MH  - Animals
MH  - Cell Membrane/metabolism
MH  - Electric Stimulation
MH  - Guinea Pigs
MH  - Ileum/drug effects/*innervation/metabolism
MH  - In Vitro Techniques
MH  - Ion Channels/drug effects/metabolism
MH  - Membrane Potentials/physiology
MH  - Myenteric Plexus/cytology/drug effects/*metabolism
MH  - Neurons/drug effects/*metabolism
MH  - Patch-Clamp Techniques
MH  - Platelet Aggregation Inhibitors/pharmacology
MH  - *Purinergic P2 Receptor Agonists
MH  - *Purinergic P2 Receptor Antagonists
MH  - Pyridoxal Phosphate/analogs & derivatives/pharmacology
MH  - Receptors, Purinergic P2/metabolism
MH  - Suramin/pharmacology
PMC - PMC1915799
EDAT- 1996/12/01 00:00
MHDA- 1996/12/01 00:01
PMCR- 1997/12/01
CRDT- 1996/12/01 00:00
PHST- 1996/12/01 00:00 [pubmed]
PHST- 1996/12/01 00:01 [medline]
PHST- 1996/12/01 00:00 [entrez]
PHST- 1997/12/01 00:00 [pmc-release]
AID - 10.1111/j.1476-5381.1996.tb16070.x [doi]
PST - ppublish
SO  - Br J Pharmacol. 1996 Dec;119(8):1541-8. doi: 10.1111/j.1476-5381.1996.tb16070.x.