| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Service de Physiologie et Pharmacologie, Faculté de Médecine et de Pharmacie, Université de Mons-Hainaut, 7000 Mons, Belgium
In
cultured vascular muscle cells, nitric oxide (NO) has been shown to
inhibit voltage-dependent Ca2+ channels, which are involved
in renal blood flow (RBF) autoregulation. Therefore, our purpose was to
specify in vivo the effects of this interaction on RBF autoregulation.
To do so, hemodynamics were investigated in anesthetized rats during
Ca2+ channel blockade before or after acute NO synthesis
inhibition. Rats were treated intravenously with vehicle (n = 10), 0.3 mg/kg body wt
NG-nitro-L-arginine-methyl ester
(L-NAME; n = 7), 4.5 µg · kg body wt
1 · min1 nifedipine
(n = 8) alone, or with nifedipine infused before (n = 8), after (n = 8), or coadministered with L-NAME
(n = 10). Baseline renal vascular resistance (RVR) averaged
14.0 ± 1.2 resistance units and did not change after vehicle. RVR
increased or decreased significantly by 27 and 29% after
L-NAME or nifedipine, respectively. Nifedipine reversed,
but did not prevent, RVR increase after or coadministered with
L-NAME. RBF autoregulation was maintained after
L-NAME, but the autoregulatory pressure limit
(PA) was significantly lowered by 15 mmHg. Nifedipine
pretreatment or coadministration with L-NAME limited
PA resetting or suppressed autoregulation at higher doses.
Results were similar with verapamil. Intrarenal blockade of
Ca2+-activated K+ channels also prevented
autoregulatory resetting by L-NAME (n = 8). These
findings suggest NO inhibits voltage-dependent Ca2+
channels and thereby modulates RBF autoregulatory efficiency.
autoregulation; renal vascular resistance; nifedipine; iberiotoxin
This article has been cited by other articles:
|
|
 |
|
  C. Lau, I. Sudbury, M. Thomson, P. L. Howard, A. B. Magil, and W. A. Cupples Salt-resistant blood pressure and salt-sensitive renal autoregulation in chronic streptozotocin diabetes Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2009; 296(6): R1761 - R1770. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. A. Cupples and B. Braam Assessment of renal autoregulation Am J Physiol Renal Physiol, April 1, 2007; 292(4): F1105 - F1123. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Shi, C. Lau, and W. A. Cupples Interactive modulation of renal myogenic autoregulation by nitric oxide and endothelin acting through ET-B receptors Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2007; 292(1): R354 - R361. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Joly, R. Seqqat, B. Flamion, N. Caron, A. Michel, J. D. Imig, and R. Kramp Increased renal vascular reactivity to ANG II after unilateral nephrectomy in the rat involves 20-HETE Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2006; 291(4): R977 - R986. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Wronski, E. Seeliger, P. B. Persson, C. Forner, C. Fichtner, J. Scheller, and B. Flemming The step response: a method to characterize mechanisms of renal blood flow autoregulation Am J Physiol Renal Physiol, October 1, 2003; 285(4): F758 - F764. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Kramp, P. Fourmanoir, and N. Caron Endothelin resets renal blood flow autoregulatory efficiency during acute blockade of NO in the rat Am J Physiol Renal Physiol, December 1, 2001; 281(6): F1132 - F1140. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. L. S. Pires, C. Julien, B. Chapuis, J. Sassard, and C. Barres Spontaneous renal blood flow autoregulation curves in conscious sinoaortic baroreceptor-denervated rats Am J Physiol Renal Physiol, January 1, 2002; 282(1): F51 - F58. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
