Effect of bicarbonate on potassium conductance of isolated perfused rat pancreatic ducts.

I Novak; R Greger

Effect of bicarbonate on potassium conductance of isolated perfused rat pancreatic ducts.

I Novak, R Greger

Molecular Integrative Physiology

Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

41 Citationer (Scopus)

Abstract

Udgivelsesdato: 1991-Aug

Originalsprog	Engelsk
Tidsskrift	Pflügers Archiv: European Journal of Physiology
Vol/bind	419
Udgave nummer	1
Sider (fra-til)	76-83
Antal sider	7
ISSN	0031-6768
Status	Udgivet - 1991

Bibliografisk note

Keywords: Animals; Barium; Bicarbonates; Electric Conductivity; Electrophysiology; Osmolar Concentration; Pancreatic Ducts; Perfusion; Potassium; Rats; Stimulation, Chemical

Citationsformater

@article{f19677c0b19011ddb04f000ea68e967b,

title = "Effect of bicarbonate on potassium conductance of isolated perfused rat pancreatic ducts.",

abstract = "The aim of this study was to investigate the role of the K+ conductance in unstimulated and stimulated pancreatic ducts and to see how it is affected by provision of exogenous HCO3-/CO2. For this purpose we have applied electrophysiological techniques to perfused pancreatic ducts, which were dissected from rat pancreas. The basolateral membrane potential PDbl of unstimulated duct cells was between -60 mV and -70 mV, and the cells had a relatively large K+ conductance in the basolateral membrane as demonstrated by (a) 20-22 mV depolarization of PDbl in response to increase in bath K+ concentration from 5 mmol/l to 20 mmol/l and (b) the effect of a K+ channel blocker, Ba2+ (5 mmol/l), which depolarized PDbl by 30-40 mV. These effects on unstimulated ducts were relatively independent of bath HCO3-/CO2. The luminal membrane seemed to have no significant K+ conductance. Upon stimulation with secretin or dibutyryl cyclic AMP, PDbl depolarized to about -35 mV in the presence of HCO3-/CO2. Notably, the K+ conductance in the stimulated ducts was now only apparent in the presence of exogenous HCO3-/CO2 in the bath solutions. Upon addition of Ba2+, PDbl depolarized by 13 +/- 1 mV (n = 7), the fractional resistance of the basolateral membrane, FRbl increased from 0.66 to 0.78 (n = 6), the specific transepithelial resistance, Rte, increased from 52 +/- 13 omega cm2 to 59 +/- 15 omega cm2 (n = 11), and the whole-cell input resistance, Rc, measured with double-barrelled electrodes, increased from 20 M omega to 26 M omega (n = 3).(ABSTRACT TRUNCATED AT 250 WORDS)",

author = "I Novak and R Greger",

note = "Keywords: Animals; Barium; Bicarbonates; Electric Conductivity; Electrophysiology; Osmolar Concentration; Pancreatic Ducts; Perfusion; Potassium; Rats; Stimulation, Chemical",

year = "1991",

language = "English",

volume = "419",

pages = "76--83",

journal = "Pfl{\"u}gers Archiv: European Journal of Physiology",

issn = "0031-6768",

publisher = "Springer",

number = "1",

}

TY - JOUR

T1 - Effect of bicarbonate on potassium conductance of isolated perfused rat pancreatic ducts.

AU - Novak, I

AU - Greger, R

N1 - Keywords: Animals; Barium; Bicarbonates; Electric Conductivity; Electrophysiology; Osmolar Concentration; Pancreatic Ducts; Perfusion; Potassium; Rats; Stimulation, Chemical

PY - 1991

Y1 - 1991

N2 - The aim of this study was to investigate the role of the K+ conductance in unstimulated and stimulated pancreatic ducts and to see how it is affected by provision of exogenous HCO3-/CO2. For this purpose we have applied electrophysiological techniques to perfused pancreatic ducts, which were dissected from rat pancreas. The basolateral membrane potential PDbl of unstimulated duct cells was between -60 mV and -70 mV, and the cells had a relatively large K+ conductance in the basolateral membrane as demonstrated by (a) 20-22 mV depolarization of PDbl in response to increase in bath K+ concentration from 5 mmol/l to 20 mmol/l and (b) the effect of a K+ channel blocker, Ba2+ (5 mmol/l), which depolarized PDbl by 30-40 mV. These effects on unstimulated ducts were relatively independent of bath HCO3-/CO2. The luminal membrane seemed to have no significant K+ conductance. Upon stimulation with secretin or dibutyryl cyclic AMP, PDbl depolarized to about -35 mV in the presence of HCO3-/CO2. Notably, the K+ conductance in the stimulated ducts was now only apparent in the presence of exogenous HCO3-/CO2 in the bath solutions. Upon addition of Ba2+, PDbl depolarized by 13 +/- 1 mV (n = 7), the fractional resistance of the basolateral membrane, FRbl increased from 0.66 to 0.78 (n = 6), the specific transepithelial resistance, Rte, increased from 52 +/- 13 omega cm2 to 59 +/- 15 omega cm2 (n = 11), and the whole-cell input resistance, Rc, measured with double-barrelled electrodes, increased from 20 M omega to 26 M omega (n = 3).(ABSTRACT TRUNCATED AT 250 WORDS)

AB - The aim of this study was to investigate the role of the K+ conductance in unstimulated and stimulated pancreatic ducts and to see how it is affected by provision of exogenous HCO3-/CO2. For this purpose we have applied electrophysiological techniques to perfused pancreatic ducts, which were dissected from rat pancreas. The basolateral membrane potential PDbl of unstimulated duct cells was between -60 mV and -70 mV, and the cells had a relatively large K+ conductance in the basolateral membrane as demonstrated by (a) 20-22 mV depolarization of PDbl in response to increase in bath K+ concentration from 5 mmol/l to 20 mmol/l and (b) the effect of a K+ channel blocker, Ba2+ (5 mmol/l), which depolarized PDbl by 30-40 mV. These effects on unstimulated ducts were relatively independent of bath HCO3-/CO2. The luminal membrane seemed to have no significant K+ conductance. Upon stimulation with secretin or dibutyryl cyclic AMP, PDbl depolarized to about -35 mV in the presence of HCO3-/CO2. Notably, the K+ conductance in the stimulated ducts was now only apparent in the presence of exogenous HCO3-/CO2 in the bath solutions. Upon addition of Ba2+, PDbl depolarized by 13 +/- 1 mV (n = 7), the fractional resistance of the basolateral membrane, FRbl increased from 0.66 to 0.78 (n = 6), the specific transepithelial resistance, Rte, increased from 52 +/- 13 omega cm2 to 59 +/- 15 omega cm2 (n = 11), and the whole-cell input resistance, Rc, measured with double-barrelled electrodes, increased from 20 M omega to 26 M omega (n = 3).(ABSTRACT TRUNCATED AT 250 WORDS)

M3 - Journal article

C2 - 1945765

SN - 0031-6768

VL - 419

SP - 76

EP - 83

JO - Pflügers Archiv: European Journal of Physiology

JF - Pflügers Archiv: European Journal of Physiology

IS - 1

ER -