Document Detail

Interrelation between baroreceptor and macula densa mechanisms in the control of renin secretion.
MedLine Citation:
PMID:  8271212     Owner:  NLM     Status:  MEDLINE    
1. It was the aim of this study to examine the interrelation between 'baroreceptor' function and the macula densa signal in the control of renin secretion from the kidneys. To this end we investigated the effects of frusemide and bumetanide, two different inhibitors of the macula densa Na(+)-K(+)-2Cl- cotransport, on pressure-dependent renin release from isolated perfused rat kidneys. In addition, pressure modulation of renin secretion from hydronephrotic kidneys devoid of macula densa structures was examined. 2. Basal flow rate through isolated kidneys was 13.5 +/- 1.0 ml min-1 g-1 at a renal artery pressure of 100 mmHg and corresponding renin secretory rates were 5.5 +/- 0.5 (ng angiotensin I (Ang I) h-1) min-1 g-1 (mean +/- S.E.M., n = 15). 3. Frusemide (10-100 microM) and bumetanide (5-50 microM) increased urine flow rates and stimulated urinary sodium excretion in a dose-dependent fashion from 13.0 +/- 2.5 mumol min-1 g-1 (n = 10) under control conditions to maximal values of 38.0 +/- 5.0 (n = 5) and 37.0 +/- 2.0 mumol min-1 g-1 (n = 5), respectively. Both drugs also induced concentration-dependent decreases of the renal vascular resistance. The vasorelaxant effects of frusemide and bumetanide were paralleled by an increase of renin secretion to a maximum of 21 +/- 4 (ng Ang I h-1) min-1 g-1 (n = 10). On a molar basis bumetanide was twice as potent as frusemide in stimulating renin secretion. 4. Lowering of the perfusion pressure from 100 to 40 mmHg resulted in a prompt increase of renin release yielding secretion rates of 92 +/- 10 (ng Ang I h-1) min-1 g-1 (n = 15). In the presence of frusemide (100 microM) and bumetanide (50 microM) renin secretion rates at 40 mmHg were 97 +/- 11 and 133 +/- 24 (ng Ang I h-1) min-1 g-1 (n = 6), respectively. Renin release stimulated by bumetanide was significantly reduced to 8.0 +/- 1.5 (ng Ang I h-1) min-1 g-1 (n = 5) by elevating the perfusion pressure from 100 to 140 mmHg. 5. Lowering the renal artery pressure from 100 to 40 mmHg in isolated perfused rat hydronephrotic kidneys devoid of tubular structures increased renin secretion rates from 4.5 +/- 1.0 to 22.5 +/- 2.5 (ng Ang I h-1) min-1 (n = 5).(ABSTRACT TRUNCATED AT 400 WORDS)
H Scholz; U Vogel; A Kurtz
Publication Detail:
Type:  In Vitro; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Journal of physiology     Volume:  469     ISSN:  0022-3751     ISO Abbreviation:  J. Physiol. (Lond.)     Publication Date:  1993 Sep 
Date Detail:
Created Date:  1994-01-31     Completed Date:  1994-01-31     Revised Date:  2009-11-18    
Medline Journal Info:
Nlm Unique ID:  0266262     Medline TA:  J Physiol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  511-24     Citation Subset:  IM    
Physiologisches Institut der Universität, Zürich, Switzerland.
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MeSH Terms
Blood Pressure / physiology
Bumetanide / pharmacology
Carrier Proteins / metabolism
Furosemide / pharmacology
Hydronephrosis / metabolism
Kidney / drug effects,  metabolism,  physiology
Kidney Tubules, Distal / drug effects,  physiology*
Membrane Proteins / metabolism
Pressoreceptors / drug effects,  physiology*
Rats, Inbred Strains
Renin / metabolism*
Sodium / urine
Sodium-Potassium-Chloride Symporters
Urodynamics / drug effects
Reg. No./Substance:
0/Carrier Proteins; 0/Membrane Proteins; 0/Sodium-Potassium-Chloride Symporters; 28395-03-1/Bumetanide; 54-31-9/Furosemide; 7440-23-5/Sodium; EC

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