Document Detail


Mechanism of renin release during renal nerve stimulation in dogs.
MedLine Citation:
PMID:  7041238     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
During renal nerve stimulation, a predominant vasoconstrictory effect on small arteries would lower blood pressure in the afferent arterioles and induce arteriolar dilation and renin release by the autoregulation mechanism. This hypothesis was examined in anaesthetized dogs by stimulating renal nerves at 4 Hz which permitted continuous reduction of renal blood flow (RBF) by 30-40%; renin release increased almost equally at control and low blood pressure, and in the non-filtering kidney during ureteral occlusion. Examinations of the relationship between RBF and arterial perfusion pressure during mechanical constriction of the renal artery showed that the lowest autoregulating pressure was 25-35 mmHg higher during nerve stimulation than in control experiments, consistent with the hypothesis of arteriolar dilation. Phenoxybenzamine, an inhibitor of alpha-adrenoceptors, abolished vasoconstriction and the effect of nerve stimulation on renin release at control blood pressure; renin release rose from 0.9 +/- 0.4 to 17 +/- 5 microgram/min before, and from 1.7 +/- 0.5 to 4.6 +/- 1.4 microgram/min after phenoxybenzamine infusion. At pressures below the range of autoregulation, phenoxybenzamine did not alter renin release response to nerve stimulation. Propranolol, a Beta-adrenergic inhibitor, attenuated the effect of nerve stimulation on renin release both at control and low blood pressure. We conclude that during renal nerve stimulation (1) renin release is caused by beta-adrenergic stimulation provided the afferent arterioles are dilated and (2) that alpha-adrenergic stimulation dilated the afferent arterioles as a consequence of a predominant vasoconstrictory effect on small arteries. Hence, by inhibiting the beta-adrenergic effect by propranolol, renin release does not increase during renal nerve stimulation. Phenoxybenzamine prevents renin release at control blood pressure because afferent arterioles are not dilated during nerve stimulation. In contrast, phenoxybenzamine does not reduce renin release during nerve stimulation at low blood pressure because afferent arterioles are dilated by the autoregulating mechanism.
Authors:
H Holdaas; O Langård; I Eide; F Kiil
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Scandinavian journal of clinical and laboratory investigation     Volume:  41     ISSN:  0036-5513     ISO Abbreviation:  Scand. J. Clin. Lab. Invest.     Publication Date:  1981 Nov 
Date Detail:
Created Date:  1982-06-14     Completed Date:  1982-06-14     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0404375     Medline TA:  Scand J Clin Lab Invest     Country:  NORWAY    
Other Details:
Languages:  eng     Pagination:  617-25     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Animals
Blood Pressure
Dogs
Electric Stimulation
Female
Homeostasis
Kidney / blood supply,  innervation*
Male
Phenoxybenzamine / pharmacology
Propranolol / pharmacology
Regional Blood Flow
Renin / secretion*
Ureter / physiology
Vasomotor System / physiology
Chemical
Reg. No./Substance:
525-66-6/Propranolol; 59-96-1/Phenoxybenzamine; EC 3.4.23.15/Renin

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


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