Document Detail


Angiotensin II effects upon the glomerular microcirculation and ultrafiltration coefficient of the rat.
MedLine Citation:
PMID:  1254727     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The effects of both synthetic and biologically produced angiotensin II (AII) upon the process of glolerular filtration were examined in the plasma-expanded (2.5% body wt) Munich-Wistar rat, by micropuncture evaluation of pressures, nephron plasma flow (rpf) and filtration rate (sngfr). Plasma expansion was chosen as a control condition because (a) response to AII was uniform and predictable, (b) endogenous generation of AII was presumably suppressed, and (c) the high control values for rpf permitted accurate determination of values for the glomerular permeability coefficient (LpA) before and during AII infusion. With subpressor quantities of synthetic Asn-1, Val-5 AII (less than 5 ng/100 g body wt/min), sngfr fell from 47.7 in the control group to 39.8 nl/min/g kidney (P less than 0.005). The rpf fell to 60% of control values (P less than 0.001). Measurement of glomerular capillary (PG) and Bowman's space (Pt) hydrostatic pressures in surface glomeruli with a servo-nulling device permitted evaluation of the hydrostatic pressure gradient (deltaP = PG - Pi). DeltaP increased from 38.1 +/- 1.2 in control to 45.9 +/- 1.3 mm Hg after Asn-1, Val-5 AII and essentially neutralized the effect of decreased rpf in sngfr. The sngfr then fell as a result of a decreased in LpA from 0.063 +/- 0.008 in control to 0.028 +/- 0.004 nl/s/g kidney/mm Hg after Asn-1, Val-5 AII (P less than 0.02). Lower doses of Asp-1, Ile-5 AII (less than 3 ng/100 g body wt/min) had no effect on sngfr, rpf, deltaP, and afferent and efferent vascular resistance, but significantly elevated systemic blood pressure, suggesting peripheral effects on smooth muscle at this low dose. LpA was 0.044 +/- 0.007 nl/s/g kidney/mm Hg after low-dose Asp-1, Ile-5 AII, and 0.063 +/- 0.008 in the control group (0.02 greater than P greater than 0.1). Higher, equally pressor doses of native AII (5 ng/100 g body wt/min) produced effects almost identical to similar quantites of synthetic Asn-1, Val-5 AII upon rpf, deltaP, sngfr, and renal vascular resistance. LpA again fell to 0.026 +/- 0.004 nl/s/g kidney/mn Hg, a value almost identical to that after the synthetic AII. Paired studies with Asp-1, Ile-5 AII also demonstrated a consistent reduction in LpA.
Authors:
R C Blantz; K S Konnen; B J Tucker
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The Journal of clinical investigation     Volume:  57     ISSN:  0021-9738     ISO Abbreviation:  J. Clin. Invest.     Publication Date:  1976 Feb 
Date Detail:
Created Date:  1976-05-18     Completed Date:  1976-05-18     Revised Date:  2010-09-07    
Medline Journal Info:
Nlm Unique ID:  7802877     Medline TA:  J Clin Invest     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  419-34     Citation Subset:  AIM; IM    
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MeSH Terms
Descriptor/Qualifier:
Angiotensin II / pharmacology*
Animals
Blood Pressure / drug effects
Blood Volume
Capillary Permeability / drug effects
Glomerular Filtration Rate / drug effects*
Hydrostatic Pressure
Kidney Glomerulus / blood supply*
Kidney Tubules, Proximal / drug effects,  physiology
Male
Microcirculation / drug effects*
Nephrons / blood supply,  drug effects,  physiology
Rats
Vascular Resistance / drug effects
Chemical
Reg. No./Substance:
11128-99-7/Angiotensin II
Comments/Corrections

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


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