HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Badzynska, B. Articles by Sadowski, J. Search for Related Content PubMed PubMed Citation Articles by Badzynska, B. Articles by Sadowski, J.

Differential effect of angiotensin II on blood circulation in the renal medulla and cortex of anaesthetised rats

Bozena Badzynska, Monika Grzelec-Mojzesowicz, Leszek Dobrowolski and Janusz Sadowski

The renal medulla is sensitive to hypoxia, and a depression of medullary circulation, e.g. in response to angiotensin II (Ang II), could endanger the function of this zone. Earlier data on Ang II effects on medullary vasculature were contradictory. The effects of Ang II on total renal blood flow (RBF), and cortical and medullary blood flow (CBF and MBF: by laser-Doppler flux) were studied in anaesthetised rats. Ang II infusion (30 ng kg^-1 min^-1 I.V.) decreased RBF 27 ± 2 % (mean ± S.E.M.), whereas MBF increased 12 ± 2 % (both P < 0.001). Non-selective blockade of Ang II receptors with saralasin (3 µg kg^-1 min^-1 I.V.) increased RBF 12 ± 2 % and decreased MBF 8 ± 2 % (P < 0.001). Blockade of AT₁ receptors with losartan (10 mg kg^-1) increased CBF 10 ± 2 % (P < 0.002) and did not change MBF. Losartan given during Ang II infusion significantly increased RBF (53 ± 7 %) and decreased MBF (27 ± 7 %). Blockade of AT₂ receptors with PD 123319 (50 µg kg^-1 min^-1 I.V.) did not change CBF or MBF. Intramedullary infusion of PD 123319 (10 µg min^-1) superimposed on intravenous Ang II infusion did not change RBF, but slightly decreased MBF (4 ± 2 %, P < 0.05). We conclude that in anaesthetised surgically prepared rats, exogenous or endogenous Ang II may not depress medullary circulation. In contrast to the usual vasoconstriction in the cortex, vasodilatation was observed, possibly related to secondary activation of vasodilator paracrine agents rather than to a direct action via AT₂ receptors.

This article has been cited by other articles:

				B. Badzynska and J. Sadowski Opposed effects of prostaglandin E2 on perfusion of rat renal cortex and medulla: interactions with the renin-angiotensin system Exp Physiol, December 1, 2008; 93(12): 1292 - 1302. [Abstract] [Full Text] [PDF]

				D. L. Mattson and C. J. Meister Renal cortical and medullary blood flow responses to L-NAME and ANG II in wild-type, nNOS null mutant, and eNOS null mutant mice Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2005; 289(4): R991 - R997. [Abstract] [Full Text] [PDF]

				L. Dobrowolski and J. Sadowski Furosemide-induced renal medullary hypoperfusion in the rat: role of tissue tonicity, prostaglandins and angiotensin II J. Physiol., September 1, 2005; 567(2): 613 - 620. [Abstract] [Full Text] [PDF]

				T.-H. Kwon, J. Nielsen, M. A. Knepper, J. Frokiaer, and S. Nielsen Angiotensin II AT1 receptor blockade decreases vasopressin-induced water reabsorption and AQP2 levels in NaCl-restricted rats Am J Physiol Renal Physiol, April 1, 2005; 288(4): F673 - F684. [Abstract] [Full Text] [PDF]

				L. M. Duke, G. A. Eppel, R. E. Widdop, and R. G. Evans Disparate Roles of AT2 Receptors in the Renal Cortical and Medullary Circulations of Anesthetized Rabbits Hypertension, August 1, 2003; 42(2): 200 - 205. [Abstract] [Full Text] [PDF]

				A. Sarkis, K. L. Liu, M. Lo, and D. Benzoni Angiotensin II and renal medullary blood flow in Lyon rats Am J Physiol Renal Physiol, February 1, 2003; 284(2): F365 - F372. [Abstract] [Full Text] [PDF]