| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
AJP - Heart and Circulatory Physiology, Vol 267, Issue 3 1085-H1092, Copyright © 1994 by American Physiological Society
ARTICLES |
M. A. Hill and G. A. Meininger
Department of Medical Physiology, College of Medicine, Texas A&M University, College Station 77843.
Studies were conducted to examine Ca2+ entry in several vasomotor situations related to myogenic properties of arterioles (basal tone, vasomotion, and responsiveness to alterations in intravascular pressure). In vivo studies were performed on small cremaster muscle arterioles of anesthetized rats. Intravascular pressure was increased using the pressure-box technique. Voltage-operated Ca2+ channel (VOC) activity was inhibited by nifedipine or methoxyverapamil and was stimulated with BAY K 8644. To examine the effect of hyperpolarization, studies were performed in the presence of pinacidil. Nifedipine and methoxyverapamil exhibited a trend toward dose-dependent dilation; however, neither agent caused dilation comparable to adenosine (10(-4) M). BAY K 8644 produced a biphasic effect, constriction below 10(-8) M, and dilation at higher levels. These data indicate that basal tone can be modulated by agents acting on VOCs; however, as high concentrations of nifedipine do not abolish tone, other mechanisms contribute. At similar concentrations, the Ca2+ channel antagonist significantly inhibited vasomotion, abolishing vasomotion at concentrations above 5 x 10(-6) M. In contrast, BAY K 8644 caused a dose-dependent increase in vasomotion amplitude (e.g., 269 +/- 52% of basal at 10(-7) M). Thus vasomotion appears highly dependent on VOCs. Experiments performed in the presence of the antagonists/agonists indicated that VOCs are not the prime determinant of constrictor responses to acute increases in intravascular pressure. Exposure to pinacidil resulted in dose-dependent vasodilatation and inhibition of vasomotion while showing little effect on acute myogenic responses. Similar effects of pinacidil were observed in isolated, cannulated, cremaster arterioles.(ABSTRACT TRUNCATED AT 250 WORDS)
This article has been cited by other articles:
|
|
 |
|
  B. R. S. Broughton, B. R. Walker, and T. C. Resta Chronic hypoxia induces Rho kinase-dependent myogenic tone in small pulmonary arteries Am J Physiol Lung Cell Mol Physiol, April 1, 2008; 294(4): L797 - L806. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Xiao, J. N. Buchholz, and L. Zhang Pregnancy attenuates uterine artery pressure-dependent vascular tone: role of PKC/ERK pathway Am J Physiol Heart Circ Physiol, June 1, 2006; 290(6): H2337 - H2343. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Kotecha and M. A. Hill Myogenic contraction in rat skeletal muscle arterioles: smooth muscle membrane potential and Ca2+ signaling Am J Physiol Heart Circ Physiol, October 1, 2005; 289(4): H1326 - H1334. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. S. Naik, S. Earley, T. C. Resta, and B. R. Walker Pressure-induced smooth muscle cell depolarization in pulmonary arteries from control and chronically hypoxic rats does not cause myogenic vasoconstriction J Appl Physiol, March 1, 2005; 98(3): 1119 - 1124. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Earley and B. R. Walker Endothelium-dependent blunting of myogenic responsiveness after chronic hypoxia Am J Physiol Heart Circ Physiol, December 1, 2002; 283(6): H2202 - H2209. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. V. Matchkov, O. S. Tarasova, M. J. Mulvany, and H. Nilsson Myogenic response of rat femoral small arteries in relation to wall structure and [Ca2+]i Am J Physiol Heart Circ Physiol, July 1, 2002; 283(1): H118 - H125. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Storme, T. A. Parker, J. P. Kinsella, R. L. Rairigh, and S. H. Abman Chronic hypertension impairs flow-induced vasodilation and augments the myogenic response in fetal lung Am J Physiol Lung Cell Mol Physiol, January 1, 2002; 282(1): L56 - L66. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Chlopicki, H. Nilsson, and M. J. Mulvany Initial and sustained phases of myogenic response of rat mesenteric small arteries Am J Physiol Heart Circ Physiol, November 1, 2001; 281(5): H2176 - H2183. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. V. Murphy, B. E. Spurrell, and M. A. Hill Tyrosine phosphorylation following alterations in arteriolar intraluminal pressure and wall tension Am J Physiol Heart Circ Physiol, September 1, 2001; 281(3): H1047 - H1056. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Dessy, N. Matsuda, J. Hulvershorn, C. L. Sougnez, F. W. Sellke, and K. G. Morgan Evidence for involvement of the PKC-alpha isoform in myogenic contractions of the coronary microcirculation Am J Physiol Heart Circ Physiol, September 1, 2000; 279(3): H916 - H923. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. R. Nurkiewicz and M. A. Boegehold Reinforcement of arteriolar myogenic activity by endogenous ANG II: susceptibility to dietary salt Am J Physiol Heart Circ Physiol, July 1, 2000; 279(1): H269 - H278. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Hill, H. Zou, M. J. Davis, S. J. Potocnik, and S. Price Transient increases in diameter and [Ca2+]i are not obligatory for myogenic constriction Am J Physiol Heart Circ Physiol, February 1, 2000; 278(2): H345 - H352. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. F. Jackson Ion Channels and Vascular Tone Hypertension, January 1, 2000; 35(1): 173 - 178. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z. Ungvari, P. Pacher, V. Kecskemeti, A. Koller, and E. P. Wei Fluoxetine Dilates Isolated Small Cerebral Arteries of Rats and Attenuates Constrictions to Serotonin, Norepinephrine, and a Voltage-Dependent Ca2+ Channel Opener • Editorial Comment Stroke, September 1, 1999; 30(9): 1949 - 1954. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. J. Davis and M. A. Hill Signaling Mechanisms Underlying the Vascular Myogenic Response Physiol Rev, April 1, 1999; 79(2): 387 - 423. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 X. Wu, J. E. Mogford, S. H. Platts, G. E. Davis, G. A. Meininger, and M. J. Davis Modulation of Calcium Current in Arteriolar Smooth Muscle by alpha vbeta 3 and alpha 5beta 1 Integrin Ligands J. Cell Biol., October 5, 1998; 143(1): 241 - 252. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. G. Welsh, W. F. Jackson, and S. S. Segal Oxygen induces electromechanical coupling in arteriolar smooth muscle cells: a role for L-type Ca2+ channels Am J Physiol Heart Circ Physiol, June 1, 1998; 274(6): H2018 - H2024. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
