TY - JOUR
T1 - Diverse effects of calcium antagonists on glomerular hemodynamics
AU - Arima, S.
AU - Ito, S.
AU - Omata, K.
AU - Tsunoda, K.
AU - Yaoita, H.
AU - Abe, K.
N1 - Copyright:
Copyright 2004 Elsevier Science B.V., Amsterdam. All rights reserved.
PY - 1996
Y1 - 1996
N2 - This study examined the direct effects of calcium antagonists on glomerular hemodynamics. Rabbit afferent (Af-) or efferent arterioles (Ef-Arts) were microperfused in vitro at constant pressure. Ef-Arts were perfused from the distal end of Af-Art through the glomerulus. Increasing doses (10-10 to 10-7 M) of nifedipine (Nif), nicardipine (Nic) or manidipine (Man) were added into the lumen of Af- or Ef-Arts preconstricted (by about 40%) with norepinephrine. Although Nif and Nic dilated Af-Arts in a dose-dependent manner, they did not cause any dilation in Ef-Arts. In contrast, Man dilated both Af- and Ef-Arts in a dose dependent manner; Man at 10-7 M dilated Af- and Ef-Arts by 71 ± 12% (N = 7) and 38 ± 3% (N = 6), respectively. Although Man's dilator effect on Ef-Art was not affected by inhibiting nitric oxide (NO) synthesis (N = 6), it was markedly attenuated by eliminating the influence of glomerulus (14 ± 3% by Man at 10-7 M, N = 5). These results demonstrate that in addition to dilating Af-Art, Man, but not Nif or Nic, dilates Ef-Art through a glomerulus-derived vasodilator(s) other than NO. Such diverse actions should be taken into consideration when calcium antagonists are used in the treatment of patients with cardiovascular and renal diseases.
AB - This study examined the direct effects of calcium antagonists on glomerular hemodynamics. Rabbit afferent (Af-) or efferent arterioles (Ef-Arts) were microperfused in vitro at constant pressure. Ef-Arts were perfused from the distal end of Af-Art through the glomerulus. Increasing doses (10-10 to 10-7 M) of nifedipine (Nif), nicardipine (Nic) or manidipine (Man) were added into the lumen of Af- or Ef-Arts preconstricted (by about 40%) with norepinephrine. Although Nif and Nic dilated Af-Arts in a dose-dependent manner, they did not cause any dilation in Ef-Arts. In contrast, Man dilated both Af- and Ef-Arts in a dose dependent manner; Man at 10-7 M dilated Af- and Ef-Arts by 71 ± 12% (N = 7) and 38 ± 3% (N = 6), respectively. Although Man's dilator effect on Ef-Art was not affected by inhibiting nitric oxide (NO) synthesis (N = 6), it was markedly attenuated by eliminating the influence of glomerulus (14 ± 3% by Man at 10-7 M, N = 5). These results demonstrate that in addition to dilating Af-Art, Man, but not Nif or Nic, dilates Ef-Art through a glomerulus-derived vasodilator(s) other than NO. Such diverse actions should be taken into consideration when calcium antagonists are used in the treatment of patients with cardiovascular and renal diseases.
UR - http://www.scopus.com/inward/record.url?scp=0001239620&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0001239620&partnerID=8YFLogxK
M3 - Article
C2 - 8743534
AN - SCOPUS:0001239620
SP - S-132-S-134
JO - Kidney International, Supplement
JF - Kidney International, Supplement
SN - 0098-6577
IS - 55
ER -