Document Detail


Activation of two inward chloride transport systems in rat femoral arterial smooth muscle in deoxycorticosterone acetate/salt hypertension.
MedLine Citation:
PMID:  9404220     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
1. Intracellular [Cl-] ([Cl-]i) was measured with ion-selective microelectrodes in rat femoral arterial smooth muscle in normotensive controls and after the induction of deoxycorticosterone acetate/salt hypertension. 2. Linear regression of [Cl-]i and time after the induction of hypertension showed good correlation (r = 0.96) for 5-6 weeks, as [Cl-]i increased from 30 +/- 1 mmol/l (mean +/- SD, n = 16), to 49 +/- 2 mmol/l (n = 9, P < 0.0001). 3. Arterial systolic blood pressure also increased linearly (r = 0.97) for 5-6 weeks as hypertension developed from 122 +/- 1 mmHg (n = 20) to 187 +/- 7 mmHg (n = 14): there was consequently a linear relationship between [Cl-]i and arterial systolic blood pressure (r = 0.96). 4. The increase in [Cl-]i was partly because Na(+)-K(+)-Cl- co-transport activity, estimated from the fall in [Cl-]i caused by bumetanide, was greater in hypertension (18 mmol/l) than in normotension (10 mmol/l). This finding, and the depolarization of the membrane potential in hypertension (-56 +/- 3 mV compared with -64 +/- 4 mV in normotension; P < 0.0001), confirms previous studies. 5. The increase in [Cl-]i was also partly due to greater activity of an Na(+)- and HCO3(-)-independent, acetazolamide-sensitive inward Cl- transport system; thus acetazolamide reduced [Cl-]i by 7 mmol/l in normotension and by 16 mmol/l in hypertension. 6. In Cl(-)-free media, the membrane potential in normotension (-59 +/- 5 mV) was not significantly different from that in hypertension (-60 +/- 4 mV). 7. The role of [Cl-]i in the depolarization of the membrane potential in hypertension is discussed.
Authors:
A A Harper; J P Davis; A R Chipperfield
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Clinical science (London, England : 1979)     Volume:  93     ISSN:  0143-5221     ISO Abbreviation:  Clin. Sci.     Publication Date:  1997 Oct 
Date Detail:
Created Date:  1997-12-29     Completed Date:  1997-12-29     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7905731     Medline TA:  Clin Sci (Lond)     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  295-8     Citation Subset:  IM    
Affiliation:
Department of Anatomy and Physiology, University of Dundee, U.K.
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MeSH Terms
Descriptor/Qualifier:
Acetazolamide / pharmacology
Animals
Anions
Bumetanide / pharmacology
Chloride Channels / drug effects,  metabolism*
Desoxycorticosterone
Diuretics / pharmacology
Hypertension / metabolism*
Male
Membrane Potentials
Microelectrodes
Muscle, Smooth, Vascular / drug effects,  metabolism*
Rats
Rats, Sprague-Dawley
Sodium Chloride
Statistics, Nonparametric
Chemical
Reg. No./Substance:
0/Anions; 0/Chloride Channels; 0/Diuretics; 28395-03-1/Bumetanide; 59-66-5/Acetazolamide; 64-85-7/Desoxycorticosterone; 7647-14-5/Sodium Chloride

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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