PMID- 18633640
OWN - NLM
STAT- MEDLINE
DCOM- 20090505
LR  - 20211020
IS  - 0031-6768 (Print)
IS  - 0031-6768 (Linking)
VI  - 457
IP  - 4
DP  - 2009 Feb
TI  - Adaptative modifications of right coronary myocytes voltage-gated K+ currents in 
      rat with hypoxic pulmonary hypertension.
PG  - 721-30
LID - 10.1007/s00424-008-0546-x [doi]
AB  - Chronic hypoxia (CH)-induced pulmonary hypertension (PHT) is well known to alter 
      K+ channels in pulmonary myocytes. PHT induces right ventricle hypertrophy that 
      increases oxygen demand; however, coronary blood flow and K+ channel adaptations 
      of coronary myocytes during PHT remain unknown. We determined whether CH and PHT 
      altered K+ currents and coronary reactivity and what impact they might have on 
      right myocardial perfusion. Right ventricle perfusion, as attested by 
      microspheres, was redistributed toward hypertrophied right ventricle [RV/LV 
      (%)=0.59+/-0.07% in CH rats vs. 0.29+/-0.03 in control rats, P<0.05]. Whole-cell 
      patch clamping showed a reduction of global outward current in hypoxic right 
      coronary artery myocytes (H-RCA), whereas hypoxic left coronary artery myocytes 
      exhibited an increase. K+ channel blockers revealed that a 4-aminopyridine 
      (4AP)-sensitive current (Kv current) was decreased in H-RCA (14.3+/-1.1 vs. 
      23.4+/-2.5 pA/pF at 60 mV in control RCA, P<0.05) and increased in hypoxic left 
      coronary artery myocytes (H-LCA; 26.4+/-3.8 vs. 11.8+/-1.6 pA/pF at 60 mV in 
      control LCA, P<0.05). Constriction to 4AP was decreased in H-RCA when compared to 
      normoxic control and increased in H-LCA when compared to LCA. Finally, we 
      observed that the expression of Kv1.2 and Kv1.5 were lower in H-RCA than that in 
      H-LCA. This study reveals that CH differentially regulates Kv channels in 
      coronary myocytes. Hypoxia decreases Kv currents and therefore reduces 
      vasoreactivity that contributes to an adaptative response leading to right 
      hypertrophied ventricle perfusion enhancement at rest.
FAU - Hyvelin, Jean-Marc
AU  - Hyvelin JM
AD  - Laboratoire de Physiopathologie de la Paroi Arterielle, EA 3852, IFR 135, UFR 
      Medecine, Universite Francois Rabelais, 10 Bld Tonnelle, BP 3223, 37032, Tours 
      Cedex, France. hyvelin@med.univ-tours.fr
FAU - Gautier, Mathieu
AU  - Gautier M
FAU - Lemaire, Marie-Christine
AU  - Lemaire MC
FAU - Bonnet, Pierre
AU  - Bonnet P
FAU - Eder, Veronique
AU  - Eder V
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20080717
PL  - Germany
TA  - Pflugers Arch
JT  - Pflugers Archiv : European journal of physiology
JID - 0154720
RN  - 0 (Peptides)
RN  - 0 (Potassium Channel Blockers)
RN  - 0 (Potassium Channels, Voltage-Gated)
RN  - 773HER9B6T (iberiotoxin)
RN  - BH3B64OKL9 (4-Aminopyridine)
SB  - IM
MH  - 4-Aminopyridine/metabolism
MH  - Animals
MH  - Coronary Vessels/*cytology/pathology
MH  - Hypertension, Pulmonary/etiology/*metabolism
MH  - Hypoxia/complications/*metabolism
MH  - Male
MH  - Membrane Potentials/physiology
MH  - Muscle Contraction/physiology
MH  - Myocytes, Cardiac/cytology/*metabolism
MH  - Myocytes, Smooth Muscle/physiology
MH  - Patch-Clamp Techniques
MH  - Peptides/metabolism
MH  - Potassium Channel Blockers/metabolism
MH  - Potassium Channels, Voltage-Gated/*metabolism
MH  - Rats
EDAT- 2008/07/18 09:00
MHDA- 2009/05/06 09:00
CRDT- 2008/07/18 09:00
PHST- 2007/11/19 00:00 [received]
PHST- 2008/06/13 00:00 [accepted]
PHST- 2008/07/18 09:00 [pubmed]
PHST- 2009/05/06 09:00 [medline]
PHST- 2008/07/18 09:00 [entrez]
AID - 10.1007/s00424-008-0546-x [doi]
PST - ppublish
SO  - Pflugers Arch. 2009 Feb;457(4):721-30. doi: 10.1007/s00424-008-0546-x. Epub 2008 
      Jul 17.