Title:

Effects of renal nerve stimulation on intrarenal blood flow in rats with intact or inactivated NO synthases

Creator:

Walkowska, Agnieszka ; Badzyńska, Bożena ; Kompanowska-Jezierska, Elżbieta ; Johns, EJ ; Sadowski, Janusz

Contributor:

Laboratory of Renal and Body Fluid Physiology, M. Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw,Poland ; Department of Physiology, University College Cork, Cork, Ireland

Publisher:

Blackwell Sci Publ

Place of publishing:

Oxford

Date issued/created:

2005

Type of object:

Journal/Article

Subject and Keywords:

intrarenal circulation ; nitric oxide synthase inhibitors ; renal medulla ; renal nerves

Abstract:

AIM:We studied a possible action of nitric oxide (NO), an intrarenal vasodilator, to buffer a decrease in renal perfusion induced by electrical stimulation of renal nerves (RNS).METHODS:In anaesthetized rats RNS was performed (15 V, 2 ms pulse duration) for 10 s at the frequencies of 2, 3.5, 5 and 7.5 Hz. The total renal blood flow (RBF), an index of cortical perfusion, was measured using a Transonic probe on the renal artery. The outer and inner medullary blood flow (OMBF, IMBF) was measured by laser-Doppler flowmetry. The effect of RNS on RBF, OMBF and IMBF was determined in rats which were either untreated or pre-treated with L-NAME (0.6 or 1.8 mg kg(-1) i.v.), or S-methyl thiocitrulline (SMTC, 20 microg kg(-1) min(-1) i.v.), a selective inhibitor of neuronal NO synthase (nNOS).RESULTS:In untreated rats, RNS decreased IMBF significantly less than RBF and OMBF. High-dose L-NAME treatment significantly enhanced the RNS induced decrease of RBF but not of OMBF or IMBF. SMTC treatment significantly enhanced the decrease of IMBF, without affecting the response of RBF or OMBF.CONCLUSION:At intact NO synthesis the inner medullary circulation is not controlled by renal nerves to the extent observed for the outer medulla or cortex. NO generated by all NOS isoforms present in the kidney buffers partly the intrarenal vasoconstriction triggered by electrical RNS. The NO derived from nNOS seems of particular importance in the control of inner medullary perfusion, interacting with NO generated by endothelial NOS and renal nerves.

Relation:

Acta Physiologica Scandinavica

Volume:

183

Issue:

1

Start page:

99

End page:

105

Resource type:

Text

Detailed Resource Type:

Article

Format:

text/xml

Language:

eng

Rights:

Rights Reserved - Free Access

Terms of use:

Copyright-protected material. May be used within the limits of statutory user freedoms

Digitizing institution:

Mossakowski Medical Research Institute PAS

Original in:

Library of the Mossakowski Medical Research Institute PAS

Projects co-financed by:

Programme Innovative Economy, 2010-2014, Priority Axis 2. R&D infrastructure

Access:

Open