Endothelial cells freshly isolated from resistance-sized pulmonary arteries possess a unique K(+) current profile.
We have, for the first time, developed a reliable method for freshly isolating viable endothelial cells from resistance-sized rat pulmonary arteries. The endothelial origin of these cells was confirmed using indirect immunofluorescence, utilizing fluorescently labeled low-density lipoprotein. Biophysical and pharmacological patch-clamp experiments conducted under quasiphysiological cationic gradients revealed that these cells had a mean resting membrane potential of approximately -38 mV and displayed a delayed-rectifying K(+) current. Immunohistochemical staining of rat lung cross-sections revealed an abundance of K(V)1.5 channel protein in pulmonary endothelium. This is the first report of a delayed-rectifying K(+) current in endothelial cells of resistance-sized pulmonary arteries. Since changes in membrane potential associated with K(+) channel activity affect release of vasoactive substances from endothelial cells, this finding has important implications for understanding the mechanisms underlying control of pulmonary vascular tone.
Hogg
D S
DS
University Department of Pharmacology, Mansfield Road, Oxford, OX1 3QT, United Kingdom.
Albarwani
S
S
Davies
A R
AR
Kozlowski
R Z
RZ
D000818:Animals; D004553:Electric Conductivity; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology*; D008297:Male; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000502:physiology*; D011651:Pulmonary Artery / Q000166:cytology / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D014655:Vascular Resistance / Q000502:physiology*
D015221:Potassium Channels