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) All Versions of this Article: 285/6/L1354    most recent 00091.2003v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science 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 Web of Science (5) Citing Articles via Google Scholar Google Scholar Articles by Linden, B. C. Articles by Cornfield, D. N. Search for Related Content PubMed PubMed Citation Articles by Linden, B. C. Articles by Cornfield, D. N.

Chronic intrauterine pulmonary hypertension compromises fetal pulmonary artery smooth muscle cell O₂ sensing

Division of Pediatric Pulmonology and Critical Care Medicine, Departments of ¹Pediatrics, ²Surgery, and ³Physiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455

Submitted 1 April 2003 ; accepted in final form 24 June 2003

To test the hypothesis that chronic intrauterine pulmonary hypertension (PHTN) compromises pulmonary artery (PA) smooth muscle cell (SMC) O₂ sensing, fluorescence microscopy was used to study the effect of an acute increase in PO₂ on the cytosolic Ca²⁺ concentration ([Ca²⁺]_i) of chronically hypoxic subconfluent monolayers of PA SMC in primary culture. PA SMCs were derived from fetal lambs with PHTN due to intrauterine ligation of the ductus arteriosus. Acute normoxia decreased [Ca²⁺]_i in control but not PHTN PA SMC. In control PA SMC, [Ca²⁺]_i increased after Ca²⁺-sensitive (K_Ca) and voltage-sensitive (K_v) K⁺ channel blockade and decreased after diltiazem treatment. In PHTN PA SMC, K_Ca blockade had no effect, whereas K_v blockade and diltiazem increased [Ca²⁺]_i. Inhibition of sarcoplasmic reticulum Ca²⁺ ATPase activity caused a greater increase in [Ca²⁺]_i in controls compared with PHTN PA SMC. Conversely, ryanodine caused a greater increase of [Ca²⁺]_i in PHTN compared with control PA SMC. K_Ca channel mRNA is decreased and K_v channel mRNA is unchanged in PHTN PA SMC compared with controls. We conclude that PHTN compromises PA SMC O₂ sensing, alters intracellular Ca²⁺ homeostasis, and changes the predominant ion channel that determines basal [Ca²⁺]_i from K_Ca to K_v.

fetus; cytosolic calcium; potassium channel

This article has been cited by other articles:

				E. R. Resnik, M. Keck, D. J. Sukovich, J. M. Herron, and D. N. Cornfield Chronic intrauterine pulmonary hypertension increases capacitative calcium entry in fetal pulmonary artery smooth muscle cells Am J Physiol Lung Cell Mol Physiol, April 1, 2007; 292(4): L953 - L959. [Abstract] [Full Text] [PDF]

				E. Resnik, J. Herron, M. Keck, D. Sukovich, B. Linden, and D. N. Cornfield Chronic intrauterine pulmonary hypertension selectively modifies pulmonary artery smooth muscle cell gene expression Am J Physiol Lung Cell Mol Physiol, March 1, 2006; 290(3): L426 - L433. [Abstract] [Full Text] [PDF]